jBPMLogo

Getting Started

Introduction and getting started with jBPM

1. Overview

1.1. What is jBPM?

jBPM is a flexible Business Process Management (BPM) Suite. It is light-weight, fully open-source (distributed under Apache License 2.0) and written in Java. It allows you to model, execute, and monitor business processes throughout their life cycle.

Process

A business process allows you to model your business goals by describing the steps that need to be executed to achieve those goals, and the order of those goals is depicted using a flow chart. This process greatly improves the visibility and agility of your business logic. jBPM focuses on executable business processes, which are business processes that contain enough detail so they can actually be executed on a BPM engine. Executable business processes bridge the gap between business users and developers as they are higher-level and use domain-specific concepts that are understood by business users but can also be executed directly.

Business processes need to be supported throughout their entire life cycle: authoring, deployment, process management and task lists, and dashboards and reporting.

The core of jBPM is a light-weight, extensible workflow engine written in pure Java that allows you to execute business processes using the latest BPMN 2.0 specification. It can run in any Java environment, embedded in your application or as a service.

On top of the core engine, a lot of features and tools are offered to support business processes throughout their entire life cycle:

  • Pluggable human task service based on WS-HumanTask for including tasks that need to be performed by human actors.

  • Pluggable persistence and transactions (based on JPA / JTA).

  • Web-based process designer to support the graphical creation and simulation of your business processes (drag and drop).

  • Web-based data modeler and form modeler to support the creation of data models and task forms

  • Web-based, customizable dashboards and reporting

  • All combined in one web-based workbench, supporting the complete BPM life cycle:

    • Modeling and deployment - author your processes, rules, data models, forms and other assets

    • Execution - execute processes, tasks, rules and events on the core runtime engine

    • Runtime Management - work on assigned task, manage process instances, etc

    • Reporting - keep track of the execution using Business Activity Monitoring capabilities

kie wb after login
  • Eclipse-based developer tools to support the modeling, testing and debugging of processes

  • Remote API to process engine as a service (REST, JMS, Remote Java API)

  • Integration with Maven, Spring, OSGi, etc.

BPM creates the bridge between business analysts, developers and end users by offering process management features and tools in a way that both business users and developers like. Domain-specific nodes can be plugged into the palette, making the processes more easily understood by business users.

jBPM supports adaptive and dynamic processes that require flexibility to model complex, real-life situations that cannot easily be described using a rigid process. We bring control back to the end users by allowing them to control which parts of the process should be executed; this allows dynamic deviation from the process.

jBPM is not just an isolated process engine. Complex business logic can be modeled as a combination of business processes with business rules and complex event processing. jBPM can be combined with the Drools project to support one unified environment that integrates these paradigms where you model your business logic as a combination of processes, rules and events.

1.2. Overview

Overview

This figure gives an overview of the different components of the jBPM project.

  • The core engine is the heart of the project and allows you to execute business processes in a flexible manner. It is a pure Java component that you can choose to embed as part of your application or deploy it as a service and connect to it through the web-based UI or remote APIs.

    • An optional core service is the human task service that will take care of the human task life cycle if human actors participate in the process.

    • Another optional core service is runtime persistence; this will persist the state of all your process instances and log audit information about everything that is happening at runtime.

    • Applications can connect to the core engine through its Java API or as a set of CDI services, but also remotely through a REST and JMS API.

  • Web-based tools allow you to model, simulate and deploy your processes and other related artifacts (like data models, forms, rules, etc.):

    • The process designer allows business users to design and simulate business processes in a web-based environment.

    • The data modeler allows non-technical users to view, modify and create data models for use in your processes.

    • A web-based form modeler also allows you to create, generate or edit forms related to your processes (to start the process or to complete one of the user tasks).

    • Rule authoring allows you to specify different types of business rules (decision tables, guided rules, etc.) for combination with your processes.

    • All assets are stored and managed by the Guvnor repository (exposed through Git) and can be managed (versioning), built and deployed.

  • The web-based management console allows business users to manage their runtime (manage business processes like start new processes, inspect running instances, etc.), to manage their task list and to perform Business Activity Monitoring (BAM) and see reports.

  • The Eclipse-based developer tools are an extension to the Eclipse IDE, targeted towards developers, and allows you to create business processes using drag and drop, test and debug your processes, etc.

Each of the component is described in more detail below.

1.3. Core Engine

The core jBPM engine is the heart of the project. It’s a light-weight workflow engine that executes your business processes. It can be embedded as part of your application or deployed as a service (possibly in the cloud). Its most important features are the following:

  • Solid, stable core engine for executing your process instances.

  • Native support for the latest BPMN 2.0 specification for modeling and executing business processes.

  • Strong focus on performance and scalability.

  • Light-weight (can be deployed on almost any device that supports a simple Java Runtime Environment; does not require any web container at all).

  • (Optional) pluggable persistence with a default JPA implementation.

  • Pluggable transaction support with a default JTA implementation.

  • Implemented as a generic process engine, so it can be extended to support new node types or other process languages.

  • Listeners to get notified about various events.

  • Ability to migrate running process instances to a new version of their process definition

The core engine can also be integrated with a few other (independent) core services:

  • The human task service can be used to manage human tasks when human actors need to participate in the process. It is fully pluggable and the default implementation is based on the WS-HumanTask specification and manages the life cycle of the tasks, task lists, task forms, and some more advanced features like escalation, delegation, rule-based assignments, etc.

  • The history log can store all information about the execution of all the processes in the engine. This is necessary if you need access to historic information as runtime persistence only stores the current state of all active process instances. The history log can be used to store all current and historic states of active and completed process instances. It can be used to query for any information related to the execution of process instances, for monitoring, analysis, etc.

1.4. Process Designer

The web-based jBPM Designer allows you to model your business processes in a web-based environment. It is targeted towards business users and offers a graphical editor for viewing and editing your business processes (using drag and drop), similar to the Eclipse plugin. It supports round-tripping between the Eclipse editor and the web-based designer. It also supports simulation of processes.

Designer
Figure 1. Web-based designer for creating BPMN2 processes

1.5. Data Modeler

Processes almost always have some kind of data to work with. The data modeler allows non-technical users to view, edit or create these data models.

Typically, a business process analyst or data analyst will capture the requirements for a process or application and turn these into a formal set of interrelated data structures. The new Data Modeler tool provides an easy, straightforward and visual aid for building both logical and physical data models, without the need for advanced development skills or explicit coding. The data modeler is transparently integrated into the workbench. Its main goals are to make data models first class citizens in the process improvement cycle and allow for full process automation through the integrated use of data structures (and the forms that will be used to interact with them).

1.6. Form Modeler

The jBPM Form Modeler is a form engine and editor that enables users to create forms to capture and display information during process or task execution, without needing any coding or template markup skills.

It provides a WYSIWYG environment to model forms that is easy to use for less technical users.

FormModeler
Figure 2. Form Modeler

Key features:

  • Form Modeling WYSIWYG UI for forms

  • Form autogeneration from data model / Java objects

  • Data binding for Java objects

  • Formula and expressions

  • Customized forms layouts

  • Forms embedding

The form modeler’s user interfaces aims both at process analysts and developers for building and testing forms.

Developers or advanced users can also leverage advanced features to customize form behavior and look&feel.

1.7. Process Instance and Task Management

Business processes can be managed through a web-based management console. It is targeted towards business users and its main features are the following:

  • Process instance management: the ability to start new process instances, get a list of running process instances, visually inspect the state of a specific process instances.

  • Human task management: being able to get a list of all your current tasks (either assigned to you or that you might be able to claim), and completing tasks on your task list (using customizable task forms).

ProcessInstanceDiagram
Figure 3. Managing your process instances

1.8. Business Activity Monitoring

As of version 6.0, jBPM comes with a full-featured BAM tooling which allows non-technical users to visually compose business dashboards. With this brand new module, to develop business activity monitoring and reporting solutions on top of jBPM has never been so easy!

BAM
Figure 4. Business Activity Monitoring

Key features:

  • Visual configuration of dashboards (Drag’n’drop).

  • Graphical representation of KPIs (Key Performance Indicators).

  • Configuration of interactive report tables.

  • Data export to Excel and CSV format.

  • Filtering and search, both in-memory or SQL based.

  • Data extraction from external systems, through different protocols.

  • Granular access control for different user profiles.

  • Look’n’feel customization tools.

  • Pluggable chart library architecture.

Target users:

  • Managers / Business owners. Consumer of dashboards and reports.

  • IT / System architects. Connectivity and data extraction.

  • Analysts / Developers. Dashboard composition & configuration.

To get further information about the new and noteworthy BAM capabilities of jBPM please read the chapter Business Activity Monitoring.

1.9. Workbench

The workbench is a web-based application that combines all of the above web-based tools into one configurable solution.

It supports the following:

  • A repository service to store your business processes and related artifacts, using a Git repository, which supports versioning, remote Git access (as a file system) and access via REST.

  • A web-based user interface to manage your business processes, targeted towards business users; it also supports the visualization (and editing) of your artifacts (the web-based editors like designer, data and form modeler are integrated here), but also categorisation, build and deployment, etc..

  • Collaboration features which enable multiple actors (for example business users and developers) to work together on the same project.

Workbench application covers complete life cycle of BPM projects starting at authoring phase, going through implementation, execution and monitoring.

kie wb after login
Figure 5. KIE workbench application

1.10. Eclipse Developer Tools

The Eclipse-based tools are a set of plugins to the Eclipse IDE and allow you to integrate your business processes in your development environment. It is targeted towards developers and has some wizards to get started, a graphical editor for creating your business processes (using drag and drop) and a lot of advanced testing and debugging capabilities.

EclipseFlow
Figure 6. Eclipse editor for creating BPMN2 processes

It includes the following features:

  • Wizard for creating a new jBPM project

  • A graphical editor for BPMN 2.0 processes

  • The ability to plug in your own domain-specific nodes

  • Validation

  • Runtime support (so you can select which version of jBPM you would like to use)

  • Graphical debugging to see all running process instances of a selected session, to visualize the current state of one specific process instance, etc.

2. Getting Started

If you would like to take a quick tutorial that will guide you through most of the components using a simple example, take a look at the Installer Chapter. This will teach you how to download and use the installer to create a demo setup, including most of the components. It uses a simple example to guide you through the most important features. Screencasts are available to help you out as well.

If you like to read more information first, the following chapters first focus on the core engine (API, BPMN 2.0, etc.). Further chapters will then describe the other components and other more complex topics like domain-specific processes, flexible processes, etc. After reading the core chapters, you should be able to jump to other chapters that you might find interesting.

You can also start playing around with some examples that are offered in a separate download. Check out the Examples chapter to see how to start playing with these.

After reading through these chapters, you should be ready to start creating your own processes and integrate the engine with your application. These processes can be started from the installer or be started from scratch.

2.1. Downloads

Latest releases can be downloaded from jBPM.org. Just pick the artifact you want:

  • bin: all the jBPM binaries (JARs) and their transitive dependencies

  • src: the sources of the core components

  • docs: the documentation

  • examples: some jBPM examples, can be imported into Eclipse

  • installer: the jBPM Installer, downloads and installs a demo setup of jBPM

  • installer-full: full jBPM Installer, downloads and installs a demo setup of jBPM, already contains a number of dependencies prepackaged (so they don’t need to be downloaded separately)

Older releases are archived at http://downloads.jboss.org/jbpm/release/.

2.2. Community

Here are a lot of useful links part of the jBPM community:

Please feel free to join us in our IRC channel at chat.freenode.net#jbpm. This is where most of the real-time discussion about the project takes place and where you can find most of the developers most of their time as well. Don’t have an IRC client installed? Simply go to http://webchat.freenode.net/, input your desired nickname, and specify #jbpm. Then click login to join the fun.

2.3. Sources

2.3.1. License

The jBPM code itself is using the Apache License v2.0.

Some other components we integrate with have their own license:

  • The new Eclipse BPMN2 plugin is Eclipse Public License (EPL) v1.0.

  • The web-based designer is based on Oryx/Wapama and is MIT License

  • The Drools project is Apache License v2.0.

2.3.2. Source code

jBPM now uses git for its source code version control system. The sources of the jBPM project can be found here (including all releases starting from jBPM 5.0-CR1):

The source of some of the other components we integrate with can be found here:

  • Other components related to the jBPM and Drools project can be found here.

  • The new Eclipse BPMN2 plugin can be found here.

  • The web-based designer can be found here

  • The kie workbench can be found here note this is an aggregate of other projects (drools-wb, jbpm-console-ng, etc)

2.3.3. Building from source

If you’re interested in building the source code, contributing, releasing, etc. make sure to read this README.

2.4. Getting Involved

We are often asked "How do I get involved". Luckily the answer is simple, just write some code and submit it :) There are no hoops you have to jump through or secret handshakes. We have a very minimal "overhead" that we do request to allow for scalable project development. Below we provide a general overview of the tools and "workflow" we request, along with some general advice.

If you contribute some good work, don’t forget to blog about it :)

2.4.1. Sign up to jboss.org

Signing to jboss.org will give you access to the JBoss wiki, forums and JIRA. Go to https://www.jboss.org/ and click "Register".

sign jbossorg

2.4.2. Sign the Contributor Agreement

The only form you need to sign is the contributor agreement, which is fully automated via the web. As the image below says "This establishes the terms and conditions for your contributions and ensures that source code can be licensed appropriately"

sign contributor

2.4.3. Submitting issues via JIRA

To be able to interact with the core development team you will need to use JIRA, the issue tracker. This ensures that all requests are logged and allocated to a release schedule and all discussions captured in one place. Bug reports, bug fixes, feature requests and feature submissions should all go here. General questions should be undertaken at the mailing lists.

Minor code submissions, like format or documentation fixes do not need an associated JIRA issue created.

submit jira

2.4.4. Fork GitHub

With the contributor agreement signed and your requests submitted to JIRA you should now be ready to code :) Create a GitHub account and fork any of the Drools, jBPM or Guvnor repositories. The fork will create a copy in your own GitHub space which you can work on at your own pace. If you make a mistake, don’t worry blow it away and fork again. Note each GitHub repository provides you the clone (checkout) URL, GitHub will provide you URLs specific to your fork.

fork github

2.4.5. Writing Tests

When writing tests, try and keep them minimal and self contained. We prefer to keep the DRL fragments within the test, as it makes for quicker reviewing. If their are a large number of rules then using a String is not practical so then by all means place them in separate DRL files instead to be loaded from the classpath. If your tests need to use a model, please try to use those that already exist for other unit tests; such as Person, Cheese or Order. If no classes exist that have the fields you need, try and update fields of existing classes before adding a new class.

There are a vast number of tests to look over to get an idea, MiscTest is a good place to start.

unit test

2.4.6. Commit with Correct Conventions

When you commit, make sure you use the correct conventions. The commit must start with the JIRA issue id, such as JBRULES-220. This ensures the commits are cross referenced via JIRA, so we can see all commits for a given issue in the same place. After the id the title of the issue should come next. Then use a newline, indented with a dash, to provide additional information related to this commit. Use an additional new line and dash for each separate point you wish to make. You may add additional JIRA cross references to the same commit, if it’s appropriate. In general try to avoid combining unrelated issues in the same commit.

Don’t forget to rebase your local fork from the original master and then push your commits back to your fork.

jira crossreferenced

2.4.7. Submit Pull Requests

With your code rebased from original master and pushed to your personal GitHub area, you can now submit your work as a pull request. If you look at the top of the page in GitHub for your work area their will be a "Pull Request" button. Selecting this will then provide a gui to automate the submission of your pull request.

The pull request then goes into a queue for everyone to see and comment on. Below you can see a typical pull request. The pull requests allow for discussions and it shows all associated commits and the diffs for each commit. The discussions typically involve code reviews which provide helpful suggestions for improvements, and allows for us to leave inline comments on specific parts of the code. Don’t be disheartened if we don’t merge straight away, it can often take several revisions before we accept a pull request. Luckily GitHub makes it very trivial to go back to your code, do some more commits and then update your pull request to your latest and greatest.

It can take time for us to get round to responding to pull requests, so please be patient. Submitted tests that come with a fix will generally be applied quite quickly, where as just tests will often way until we get time to also submit that with a fix. Don’t forget to rebase and resubmit your request from time to time, otherwise over time it will have merge conflicts and core developers will general ignore those.

submit pull request

2.5. What to do if I encounter problems or have questions?

You can always contact the jBPM community for assistance.

IRC: #jbpm at chat.freenode.net

jBPM Setup Google Group - Installation, configuration, setup and administration discussions for the Workbench, Eclipse, runtime environments and general enterprise architectures.

jBPM Usage Google Group - Authoring, executing and managing processes with jBPM. Any questions regarding the use of jBPM. General API help and best practices in building BPM systems.

Legacy jBPM User Forum - serves as an archive; post new questions to one of the Google Groups above

3. jBPM Installer

3.1. Prerequisites

This script assumes you have Java JDK 1.6+ (set as JAVA_HOME), and Ant 1.7+ installed. If you don’t, use the following links to download and install them:

To check whether Java and Ant are installed correctly, type the following commands inside a command prompt:

java -version

ant -version

This should return information about which version of Java and Ant you are currently using.

3.2. Downloading the Installer

First of all, you need to download the installer and unzip it on your local file system. There are two versions

  • full installer - already contains a lot of the dependencies that are necessary during the installation

  • minimal installer - contains only the installer and will download all required dependencies on the fly

In general, it is probably best to download the full installer: jBPM-7.0.0.Final-installer-full.zip

You can also download the latest SNAPSHOT build (only for the minimal installer).

3.3. Demo Setup

The easiest way to get started is to simply run the installation script to install the demo setup. The demo install will setup all the web tooling (on top of WildFly) and Eclipse tooling in a pre-configured setup. Go into the jbpm-installer folder where you unzipped the installer and (from a command prompt) run:

ant install.demo

This will:

  • Download WildFly application server

  • Configure and deploy the web tooling

  • Download Eclipse

  • Install the Drools and jBPM Eclipse plugin

  • Install the Eclipse BPMN 2.0 Modeler

Running this command could take a while (REALLY, not kidding, we are for example downloading an Eclipse installation, even if you downloaded the full installer, specifically for your operating system).

The script always shows which file it is downloading (you could for example check whether it is still downloading by checking the whether the size of the file in question in the jbpm-installer/lib folder is still increasing). If you want to avoid downloading specific components (because you will not be using them or you already have them installed somewhere else), check below for running only specific parts of the demo or directing the installer to an already installed component.

Once the demo setup has finished, you can start playing with the various components by starting the demo setup:

ant start.demo

This will:

  • Start H2 database server

  • Start WildFly application server

  • Start Eclipse

Now wait until the process management console comes up:

It could take a minute to start up the application server and web application. If the web page doesn’t show up after a while, make sure you don’t have a firewall blocking that port, or another application already using the port 8080. You can always take a look at the server log jbpm-installer/wildfly-8.1.0.Final/standalone/log/server.log

Finally, if you also want to use the DashBuilder for reporting (which is implemented as a separate war), you can now also install this:

ant install.dashboard.into.jboss

Once everything is started, you can start playing with the Eclipse and web tooling, as explained in the following sections.

If you only want to try out the web tooling and do not wish to download and install the Eclipse tooling, you can use these alternative commands:

ant install.demo.noeclipse
ant start.demo.noeclipse

Similarly, if you only want to try out the Eclipse tooling and do not wish to download and install the web tooling, you can use these alternative commands:

ant install.demo.eclipse
ant start.demo.eclipse

Now continue with the 10-minute tutorials. Once you’re done playing and you want to shut down the demo setup, you can use:

ant stop.demo

If at any point in time would like to start over with a clean demo setup - meaning all changes you did inside the web tooling and/or saved in the database will be lost, you can run the following command (after which you can run the installer again from scratch, note that this cannot be undone):

ant clean.demo

3.4. 10-Minute Tutorial using the Workbench

Open up the process management console:

It could take a minute to start up the AS and web application. If the web page doesn’t show up after a while, make sure you don’t have a firewall blocking that port, or another application already using the port 8080. You can always take a look at the server log jbpm-installer/jboss-as-7.1.1.Final/standalone/log/server.log

Log in, using krisv / krisv as username / password.

Using a prebuilt Evaluation example, the following screencast gives an overview of how to manage your process instances. It shows you:

  • How to build and deploy a process

  • How to start a new process instance

  • How to look up the current status of a running process instance

  • How to look up your tasks

  • How to complete a task

  • How to generate reports to monitor your process execution

    ScreencastConsole

The workbench supports the entire life cycle of your business processes: authoring, deployment, process management, tasks and dashboards.

  • The project authoring perspective allows you to look at existing repositories, where each project can contain business processes (but also business rules, data models, forms, etc.). By default, the workbench will download two sample playground repositories, containing examples to look at.

    • In this screencast, the Evaluation project inside the jbpm-playground repository is used.

  • The project explorer shows all available artifacts:

    • evaluation: business process describing the evaluation process as a sequence of tasks

    • evaluation-taskform: process form to start the evaluation process

    • PerformanceEvaluation-taskform: task form to perform the evaluation tasks

  • To make a process available for execution, you need to successfully build and deploy it first. To do so, open up the Project Editor (from the Tools menu) and click Build & Deploy.

  • To manage your process definitions and instances, click on the "Process Management" menu option at the top menu bar an select one of available options depending on you interest:

    • Process Definitions - lists all available process definitions

    • Process Instances - lists all active process instances (allows to show completed, aborted as well by changing filter criteria)

  • Process definitions panel allow you to start a new process instance by clicking on the "Play" button. The process form (as defined in the project) will be shown, where you need to fill in the necessary information to start the process. In this case, you need to fill the user you want to start an evaluation for (in this case use "krisv") and a reason for the request, after which you can complete the form. Some details about the process instance that was just started will be shown in the process instance details panel. From there you can access additional details:

    • Process model - to visualize current state of the process

    • Process variables - to see current values of process variables

    The process instance that you just started is first requiring a self-evaluation of the user and is waiting until the user has completed this task.

  • To see the tasks that have been assigned to you, choose the "Tasks" menu option on the top bar and select "Task List" (you may need to click refresh to update your task view). The personal tasks table should show a "Performance Evaluation" task reserved for you. After starting the task, you can complete the task, which will open up the task form related to this task. You can fill in the necessary data and then complete the form and close the window. After completing the task, you could check the "Process Instances" once more to check the progress of your process instance. You should be able to see that the process is now waiting for your HR manager and project manager to also perform an evaluation. You could log in as "john" / "john" and "mary" / "mary" to complete these tasks.

  • After starting and/or completing a few process instances and human tasks, you can generate a report of what has happened so far. Under "Dashboards", select "Process & Task Dashboard". This is a set of see predefined charts that allow users to spot what is going on in the system. Charts can be fully customized as well, as explained in the Business Activity Monitoring chapter.

3.5. 10-Minute Tutorial using Eclipse

The following screencast gives an overview of how to use the Eclipse tooling. It shows you:

  • How to import and execute the evaluation sample project

    • Import the evaluation project (included in the jbpm-installer)

    • Open the Evaluation.bpmn process

    • Open the com.sample.ProcessTest Java class

    • Execute the ProcessTest class to run the process

  • How to create a new jBPM project (including sample process and JUnit test)

    ScreencastEclipse

You can import the evaluation project - a sample included in the jbpm-installer - by selecting "File → Import …​", select "Existing Projects into Workspace" and browse to the jbpm-installer/sample/evaluation folder and click "Finish". You can open up the evaluation process and the ProcessTest class. To execute the class, right-click on it and select "Run as …​ - Java Application". The console should show how the process was started and how the different actors in the process completed the tasks assigned to them, to complete the process instance.

You could also create a new project using the jBPM project wizard. The sample projects contain a process and an associated Java file to start the process. Select "File - New …​ - Project …​" and under the "jBPM" category, select "jBPM project" and click "Next". Give the project a name and click "Next". You can choose from a simple HelloWorld example or a slightly more advanced example using persistence and human tasks. If you select the latter and click Finish, you should see a new project containing a "sample.bpmn" process and a "com.sample.ProcessTest" JUnit test class. You can open the BPMN2 process by double-clicking it. To execute the process, right-click on ProcessTest.java and select "Run As - Java Application".

3.6. Configuration

3.6.1. Playgrounds

The workbench by default brings two sample playground repositories (by cloning the jbpm-playground repository hosted on GitHub). In cases where this is not wanted (access to Internet might not be available or there might be a need to start with a completely clean installation of the workbench) this default behavior can be turned off. To do so, change the following system property in the start.jboss target to false in the build.xml:

-Dorg.kie.demo=false

Note that this will create a completely empty version of the workbench. To be able to start modeling processes, the following elements need to be created first:

  • Organizational unit

  • Repository (new or clone existing one)

  • Project

3.6.2. Workbench Authentication

The workbench web application is using the pre-installed other security domain for authenticating and authorizing users (as specified in the WEB-INF/jboss-web.xml inside the WARs).

The application server uses by default property files based realms - Please note that this configuration is intended only for demo purposes (users, roles and passwords are stored in simple property files on the filesystem).

Authentication is configured in the standalone.xml file as follows:

<security-domain name="other" cache-type="default">
    <authentication>
        <login-module code="Remoting" flag="optional">
            <module-option name="password-stacking" value="useFirstPass"/>
        </login-module>
        <login-module code="RealmDirect" flag="required">
            <module-option name="password-stacking" value="useFirstPass"/>
        </login-module>
        <login-module code="org.kie.security.jaas.KieLoginModule" flag="optional" module="deployment.jbpm-console.war"/>
    </authentication>
</security-domain>
<security-realm name="ApplicationRealm">
    <authentication>
        <local default-user="$local" allowed-users="*" skip-group-loading="true"/>
        <properties path="users.properties" relative-to="jboss.server.config.dir"/>
    </authentication>
    <authorization>
        <properties path="roles.properties" relative-to="jboss.server.config.dir"/>
    </authorization>
</security-realm>

These are the default users:

Table 1. Default users
Name Password Workbench roles Task roles

admin

admin

admin,analyst

krisv

krisv

admin,analyst

john

john

analyst

Accounting,PM

mary

mary

analyst

HR

sales-rep

sales-rep

analyst

sales

jack

jack

analyst

IT

katy

katy

analyst

HR

salaboy

salaboy

admin,analyst

IT,HR,Accounting

kieserver

kieserver1!

kie-server

Authentication can be customized by using any of the following options:

  • The users and groups management screens on the workbench web application.

Navigate into the workbench web application and click on the menu HomeSecurity.

  • The add-user script that comes by default on Wildfly/EAP.

Example for Linux platforms - run the following command and follow the script instructions:

/bin/sh $JBOSS_HOME/bin/add-user.sh
  --user-properties $JBOSS_HOME/standalone/configuration/users.properties
  --group-properties $JBOSS_HOME/standalone/configuration/roles.properties
  --realm ApplicationRealm

3.6.3. Using your own database with the jBPM installer

3.6.3.1. Introduction

jBPM uses the Java Persistence API specification (v2) to allow users to configure whatever datasource they want to use to persist runtime data. As a result, the instructions below describe how you should configure a datasource when using JPA on JBoss application server (e.g. AS7, EAP6 or Wildfly8) using a persistence.xml file and configuring your datasource and driver in your application server’s standalone.xml , similar to how you would configure any other application using JPA on JBoss application server. The installer automates some of this (like copying the right files to the right location after installation).

By default, the jbpm-installer uses an H2 database for persisting runtime data. In this section we will:

  1. modify the persistence settings for runtime persistence of process instance state

  2. test the startup with our new settings!

You will need a local instance of a database, in this case we will use MySQL.

3.6.3.2. Database setup

In the MySQL database used in this quickstart, create a single user:

  • user/schema "jbpm" with password "jbpm" (which will be used to persist all entities)

If you end up using different names for your user/schemas, please make a note of where we insert "jbpm" in the configuration files.

If you want to try this quickstart with another database, a section at the end of this quickstart describes what you may need to modify.

3.6.3.3. Configuration

The following files define the persistence settings for the jbpm-installer demo:

  • jbpm-installer/db/jbpm-persistence-JPA2.xml

  • Application server configuration

    • standalone-*.xml

There are multiple standalone.xml files available (depending on whether you are using JBoss AS7, JBoss EAP6 or Wildfly8 and whether you are running the normal or full profile). The full profile is required to use the JMS component for remote integration, so will be used by default by the installer. Best practice is to update all standalone.xml files to have consistent setup but most important is to have standalone-full-wildfly-8.1.0.Final.xml properly configured as this is used by default by the installer.

Do the following:

  • Disable H2 default database and enable MySQL database in build.properties

    # default is H2
    # H2.version=1.3.168
    # db.name=h2
    # db.driver.jar.name=${db.name}.jar
    # db.driver.download.url=http://repo1.maven.org/maven2/com/h2database/h2/${H2.version}/h2-${H2.version}.jar
    #mysql
    db.name=mysql
    db.driver.module.prefix=com/mysql
    db.driver.jar.name=mysql-connector-java-5.1.18.jar
    db.driver.download.url=https://repository.jboss.org/nexus/service/local/repositories/central/content/mysql/mysql-connector-java/5.1.18/mysql-connector-java-5.1.18.jar

    You might want to update the db driver jar name and download url to whatever version of the jar matches your installation.

  • db/jbpm-persistence-JPA2.xml :

    This is the JPA persistence file that defines the persistence settings used by jBPM for both the process engine information, the logging/BAM information and task service.

    In this file, you will have to change the name of the hibernate dialect used for your database.

    The original line is:

    <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/>

    In the case of a MySQL database, you need to change it to:

    <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>

    For those of you who decided to use another database, a list of the available hibernate dialect classes can be found here.

  • standalone-full-wildfly-8.1.0.Final.xml :

    Standalone.xml and standalone-full.xml are the configuration for the standalone JBoss application server. When the installer installs the demo, it copies these files to the standalone/configuration directory in the JBoss server directory. Since the installer uses Wildfly8 by default as application server, you probably need to change standalone-full-wildfly-8.1.0.Final.xml .

    We need to change the datasource configuration in standalone-full.xml so that the jBPM process engine can use our MySQL database. The original file contains (something very similar to) the following lines:

    <datasource jta="true" jndi-name="java:jboss/datasources/jbpmDS" pool-name="H2DS" enabled="true" use-java-context="true" use-ccm="true">
        <connection-url>jdbc:h2:tcp://localhost/~/jbpm-db;MVCC=TRUE</connection-url>
        <driver>h2</driver>
        <security>
           <user-name>sa</user-name>
        </security>
    </datasource>
    <drivers>
        <driver name="h2" module="com.h2database.h2">
            <xa-datasource-class>org.h2.jdbcx.JdbcDataSource</xa-datasource-class>
        </driver>
    </drivers>

    Change the lines to the following:

    <datasource jta="true" jndi-name="java:jboss/datasources/jbpmDS" pool-name="MySQLDS" enabled="true" use-java-context="true" use-ccm="true">
        <connection-url>jdbc:mysql://localhost:3306/jbpm</connection-url>
        <driver>mysql</driver>
        <security>
           <user-name>jbpm</user-name>
           <password>jbpm</password>
        </security>
    </datasource>

    and add an additional driver configuration:

    <driver name="mysql" module="com.mysql">
        <xa-datasource-class>com.mysql.jdbc.jdbc2.optional.MysqlXADataSource</xa-datasource-class>
    </driver>
  • To install driver jars in JBoss application server (Wildfly8, EAP6, etc.), it is recommended to install the driver jar as a module. The installer already takes care of this mostly: it will copy the driver jar (you specified in the build.properties ) to the right folder inside the modules directory of your server and put a matching module.xml next to it. For MySQL, this file is called db/mysql_module.xml . Open this file and make sure that the file name of the driver jar listed there is identical the driver jar name you specified in the build.properties (including the version). Note that, even if you simply uncommented the default MySQL configuration, you will still need to add the right version here.

  • Starting the demo

    We’ve modified all the necessary files at this point. Now would be a good time to make sure your database is started up as well!

    The installer script copies this file into the jbpm-console WAR before the WAR is installed on the server. If you have already run the installer, it is recommended to stop the installer and clean it first using

    ant stop.demo

    and

    ant clean.demo

    before continuing.

    Run

    ant install.demo

    to (re)install the wars and copy the necessary configuration files. Once you’ve done that, (re)start the demo using

    ant start.demo
  • Problems?

    If this isn’t working for you, please try the following:

    • Please double check the files you’ve modified: I wrote this, but still made mistakes when changing files!

    • Please make sure that you don’t secretly have another (unmodified) instance of JBoss AS running.

    • If neither of those work (and you’re using MySQL), please do then let us know.

3.6.3.4. Using a different database

If you decide to use a different database with this demo, you need to remember the following when going through the steps above:

  • Configuring the jBPM datasource in standalone.xml:

    • After locating the java:jboss/datasources/jbpmDS datasource, you need to provide the following properties specific to your database:

      • Change the url of your database

      • Change the user-name and password

      • Change the name of the driver (which you’ll create next)

        For example:

        <datasource jta="true" jndi-name="java:jboss/datasources/jbpmDS" pool-name="PostgreSQLDS" enabled="true" use-java-context="true" use-ccm="true">
            <connection-url>jdbc:postgresql://localhost:5432/jbpm</connection-url>
            <driver>postgresql</driver>
            <security>
                <user-name>jbpm</user-name>
                <password>jbpm</password>
            </security>
        </datasource>
    • Add an additional driver configuration:

      • Change the name of the driver to match the name you specified when configuring the datasource in the previous step

      • Change the module of the driver: the database driver jar should be installed as a module (see below) and here you should reference the unique name of the module. Since the installer can take care of automatically generating this module for you (see below), this should match the db.driver.module.prefix property in build.properties (where forward slashes are replaced by a point). In the example below, I used org/postgresql as db.driver.module.prefix which means that I should then use org.postgresql as module name for the driver.

      • Fill in the correct name of the XA datasource class to use.

    For example:

    +

    <driver name="postgresql" module="org.postgresql">
        <xa-datasource-class>org.postgresql.xa.PGXADataSource</xa-datasource-class>
    </driver>
  • You need to change the dialect in persistence.xml to the dialect for your database, for example:

    <property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>
  • In order to make sure your driver will be correctly installed in the JBoss application server, there are typically multiple options, like install as a module or as a deployment. It is recommended to install the driver as a module for AS7, EAP6 and Wildfly8. For example, for AS7 both ways are explained here.

    • Install the driver JAR as a module, which is what the install script does.

    • Otherwise, you can modify and install the downloaded JAR as a deployment. In this case you will have to copy the JAR yourself to the standalone/deployments directory.

    If you choose to install driver as JBoss module (recommended), please do the following:

    • In build.properties, disable the default H2 driver properties

      # default is H2
      # H2.version=1.3.168
      # db.name=h2
      # db.driver.jar.name=h2-${H2.version}.jar
      # db.driver.download.url=http://repo1.maven.org/maven2/com/h2database/h2/${H2.version}/h2-${H2.version}.jar
    • Uncomment one of the other example configs (mysql or postgresql) or create your own:

      #postgresql
      db.name=postgresql
      db.driver.module.prefix=org/postgresql
      db.driver.jar.name=postgresql-9.1-902.jdbc4.jar
      db.driver.download.url=https://repository.jboss.org/nexus/content/repositories/thirdparty-uploads/postgresql/postgresql/9.1-902.jdbc4/postgresql-9.1-902.jdbc4.jar
      • Change the db.name property in build.properties to a name for your database.

      • Change the db.driver.module.prefix property to a name for the module of your driver. Note that this should match the module property when configuring the driver in standalone.xml (where forward slashes in the prefix here are replaced by a point). In the example above, I used org/postgresql as db.driver.module.prefix which means that I should then use org.postgresql as module name for the driver.

      • Change the db.driver.jar.name property to the name of the jar that contains your database driver.

      • Change the db.driver.download.url property to where the driver jar can be downloaded. Alternatively, you could manually download the jar yourself, and place it in the db/drivers folder, using the same name as you specified in the db.driver.jar.name property.

    • Lastly, you’ll have to create the db/${db.name}_module.xml file. As an example you can use db/mysql_module.xml, so just make a copy of it and:

      • Change the name of the module to match the driver module name above

      • Change the name of the module resource path to the name of the db.driver.jar.name property.

    • For example, the top of the file would look like:

<module xmlns="urn:jboss:module:1.0" name="org.postgresql">
   <resources>
     <resource-root path="postgresql-9.1-902.jdbc4.jar"/>
   </resources>

3.6.4. jBPM database schema scripts (DDL scripts)

By default the demo setup makes use of Hibernate auto DDL generation capabilities to build up the complete database schema, including all tables, sequences, etc. This might not always be welcomed (by your database administrator), and thus the installer provides DDL scripts for most popular databases.

Table 2. DDL scripts
Database name Location

db2

jbpm-installer/db/ddl-scripts/db2

derby

jbpm-installer/db/ddl-scripts/derby

h2

jbpm-installer/db/ddl-scripts/h2

hsqldb

jbpm-installer/db/ddl-scripts/hsqldb

mysql5

jbpm-installer/db/ddl-scripts/mysql5

mysqlinnodb

jbpm-installer/db/ddl-scripts/mysqlinnodb

oracle

jbpm-installer/db/ddl-scripts/oracle

postgresql

jbpm-installer/db/ddl-scripts/postgresql

sqlserver

jbpm-installer/db/ddl-scripts/sqlserver

sqlserver2008

jbpm-installer/db/ddl-scripts/sqlserver2008

DDL scripts are provided for both jBPM and Quartz schemas although Quartz schema DDL script is only required when the timer service should be configured with Quartz database job store. See the section on timers for additional details.

This can be used to initially create the database schema, but it can also serve as the basis for any\ optimization that needs to be applied - such as indexes, etc.

If you use PostgreSQL with jBPM, you also need to run jbpm-installer/db/ddl-scripts/postgresql/postgresql-jbpm-lo-trigger-clob.sql

This script creates triggers for jBPM tables to protect CLOB references of large objects. Without the triggers, vacuumlo tool (https://www.postgresql.org/docs/9.4/static/vacuumlo.html) deletes active large objects so causes an issue to jBPM. If you are already running jBPM without the triggers, you also need to run the following SQLs after applying the triggers to protect existing CLOB.

insert into jbpm_active_clob ( loid ) select cast(expression as oid) from booleanexpression where expression is not null;
insert into jbpm_active_clob ( loid ) select cast(body as oid) from email_header where body is not null;
insert into jbpm_active_clob ( loid ) select cast(text as oid) from i18ntext where text is not null;
insert into jbpm_active_clob ( loid ) select cast(text as oid) from task_comment where text is not null;
insert into jbpm_active_clob ( loid ) select cast(qexpression as oid) from querydefinitionstore where qexpression is not null;
insert into jbpm_active_clob ( loid ) select cast(deploymentunit as oid) from deploymentstore where deploymentunit is not null;

3.6.5. jBPM installer script

jBPM installer ant script performs most of the work automatically and usually does not require additional attention but in case it does, here is a list of available targets that might be needed to perform some of the steps manually.

Table 3. jBPM installer available targets
Target Description

clean.db

cleans up database used by jBPM demo (applies only to H2 database)

clean.demo

cleans up entire installation so new installation can be performed

clean.demo.noeclipse

same as clean.demo but does not remove Eclipse

clean.eclipse

removes Eclipse and its workspace

clean.generated.ddl

removes DDL scripts generated if any

clean.jboss

removes application server with all its deployments

clean.jboss.repository

removes repository content for demo setup (guvnor Maven repo, niogit, etc)

download.dashboard

downloads jBPM dashboard component (BAM)

download.db.driver

downloads DB driver configured in build.properties

download.ddl.dependencies

downloads all dependencies required to run DDL script generation tool

download.droolsjbpm.eclipse

downloads Drools and jBPM Eclipse plugin

download.eclipse

downloads Eclipse distribution

download.jboss

downloads JBoss Application Server

download.jBPM.bin

downloads jBPM binary distribution (jBPM libs and its dependencies)

download.jBPM.console

downloads jBPM console for JBoss AS

install.dashboard.into.jboss

installs jBPM dashboard into JBoss AS

install.db.files

installs DB driver as JBoss module

install.demo

installs complete demo environment

install.demo.eclipse

installs Eclipse with all jBPM plugins, no server installation

install.demo.noeclipse

similar to install.demo but skips Eclipse installation

install.dependencies

installs custom libraries (such as work item handlers, etc) into the jBPM console

install.droolsjbpm-eclipse.into.eclipse

installs droolsjbpm Eclipse plugin into Eclipse

install.eclipse

install Eclipse IDE

install.jboss

installs JBoss AS

install.jBPM-console.into.jboss

installs jBPM console application into JBoss AS

3.7. Frequently Asked Questions

Some common issues are explained below.

  1. What if the installer complains it cannot download component X?

    Are you connected to the Internet? Do you have a firewall turned on? Do you require a proxy? It might be possible that one of the locations we’re downloading the components from is temporarily offline. Try downloading the components manually (possibly from alternate locations) and put them in the jbpm-installer/lib folder.

  2. What if the installer complains it cannot extract / unzip a certain JAR/WAR/zip?

    If your download failed while downloading a component, it is possible that the installer is trying to use an incomplete file. Try deleting the component in question from the jbpm-installer/lib folder and reinstall, so it will be downloaded again.

  3. What if I have been changing my installation (and it no longer works) and I want to start over again with a clean installation?

    You can use ant clean.demo to remove all the installed components, so you end up with a fresh installation again.

  4. I sometimes see exceptions when trying to stop or restart certain services, what should I do?

    If you see errors during shutdown, are you sure the services were still running? If you see exceptions during restart, are you sure the service you started earlier was successfully shutdown? Maybe try killing the services manually if necessary.

  5. Something seems to be going wrong when running Eclipse but I have no idea what. What can I do?

    Always check the consoles for output like error messages or stack traces. You can also check the Eclipse Error Log for exceptions. Try adding an audit logger to your session to figure out what’s happening at runtime, or try debugging your application.

  6. Something seems to be going wrong when running the a web-based application like the jbpm-console. What can I do?

    You can check the server log for possible exceptions: jbpm-installer/jboss-as-{version}/standalone/log/server.log (for JBoss AS7).

For all other questions, try contacting the jBPM community as described in the Getting Started chapter.

4. Examples

4.1. Introduction

The web-based workbench by default will install two sample repositories that contain various sample projects that help you getting started. This section shows different examples that can be found in the jbpm-playground repository (also available here: https://github.com/kiegroup/jbpm-playground). All these examples are high level and business oriented.

If you want to contribute with these examples please get in touch with any member of the jBPM/Drools Team.

4.2. Importing Projects through Git

To import the Human Resources example, as well as other examples, follow these steps:

  1. Logging into Workbench

    1. On the command line, change into the $SERVER_HOME/bin/ directory and execute the following command:

      • for Unix environment:

        ./standalone.sh
      • for Windows environment:

        ./standalone.bat
    2. Once your server is up and running, open the following address in a web browser:

      http://localhost:8080/business-central

      This opens the login page.

    3. Log into Workbench with the user credentials created during installation.

  2. Importing Projects Through Git

    1. Click Authoring ▸ Administration.

    2. Click Repositories ▸ Clone repository.

    3. In the New Repository dialogue, enter following information:

      • Repository Name: for example, playground.

      • Organizational Unit: select your organizational unit, for example example.

      • Git URL : enter the Git URL you want to import, for example: https://github.com/kiegroup/jbpm-playground.

    4. Click Clone.

This will import a number of premade examples into your instance of jBPM Red Hat JBoss BPM Suite.

4.3. Human Resources Example

The Human Resource Example’s use case can be described as follows: A company wants to hire new developers. In this process, three departments (that is the Human resources, IT, and Accounting) are involved. These departments are represented by three users: Katy, Jack, and John respectively.

human resources high level
Business process designed for the Human Resource Example's use caseBusiness Process

Note that only four out of the six defined activities within the business process are User Tasks. User Tasks require human interaction. The other two tasks are Service Tasks, which are automated and connected to other systems.

Each instance of the process will follow certain actions:

  • The human resources team performs the initial interview with the candidate.

  • The IT department team performs the technical interview.

  • Based on the output from the previous two steps, the accounting team creates a job proposal.

  • When the proposal has been drafted, it is automatically sent to the candidate via email.

  • If the candidate accepts the proposal, a new meeting to sign the contract is scheduled.

  • Finally, if the candidate accepts the proposal, the system posts a message about the new hire using Twitter service connector.

Note, that Jack, John, and Katy represent any employee within the company with appropriate role assigned.

4.3.1. The Kie Project: human-resources

To start exploring the project:

  1. Click Authoring ▸ Project Authoring.

  2. Click BUSINESS PROCESSES ▸ hiring.

The authoring perspective contains the hiring.bpmn2 process and a set of forms for each human task. Click these assets to explore. Notice that different editors open for different types of assets.

human resources hiring bpmn

4.3.2. Building the Human Resources Example

To build the Project:

  1. Click Authoring ▸ Project Authoring.

  2. Click the project name.

  3. Click "Build & Deploy".

Build & Deploy creates a new JAR artifact that is deployed to the runtime environment as a new deployment unit.

human resources build and deploy

After successfully building and deploying your project, you can verify its presence in the Deployments tab. Click Deploy ▸ Deployments to do so.

human resources deployment screen
Figure 7. Deployment Units Section

You can find all the deployed units in the Deployments tab. When you Build & Deploy a project from the Project Editor, it is deployed using the default configurations. That means using the Singleton Strategy, the default Kie Base and the default Kie Session.

If you want a more advanced deployment, undeploy and re-deploy your artifacts using their GAV and selecting non-default settings. Then, you will be able to set a different strategy, or use a non-default Kie Base or Kie Session.

Once your artifact that contains the process definition is deployed, the Process Definition will become available in Process Management ▸ Process Definitions.

4.3.3. Create a new Process Instance

To create new process instances:

Click Process Management ▸ Process Definitions.

Start your instance:

human resources process definitions
You can start process instances using any of the two highlighted options.Starting Process Instances

The Process Definitions tab contains all the available process definitions in the runtime environment. In order to add new process definitions, build and deploy a new project.

Most processes require additional information to create a new process instance. This is done through forms. For this project, fill in the name of the candidate that is to be interviewed.

When you click Submit , you create a new process instance. This creates the first task, that is available for the Human Resources team. To see the task, you need to logout and log in as a user with the appropriate role assigned, that is someone from the Human Resources.

When you start the process, you can interact with the human tasks. To do so, click Task ▸ Tasks.

Note that in order to see the tasks in the task list, you need to belong to specific user groups, for which the task is designed. For example, the HR Interview task is visible only for the members of the HR group, and the Tech Interview Task is visible only to the members of the IT group.

4.4. Examples zip

A zip file of examples can also be downloaded from the downloads page, containing various examples that can be opened in the Eclipse-based Developers Tools. Simply download and unzip the examples artefact and import into your Eclipse workspace.

5. jBPM Version Migration Guide

5.1. Deprecated in jBPM 7

Table 4. Deprecated properties
Property Description jBPM 7 Behavior

jbpm.v5.id.strategy

This property is responsible for how the id value of NodeInstance instances was generated. Setting this property to true meant that the same strategy used in jBPM 5 was still used, even though this (jBPM 5) strategy meant that NodeInstance ids were not unique.

In jBPM 7, this is no longer possible: all NodeInstance id’s are unique.

jBPM Core

Using the jBPM Core Engine

6. Core Engine API

6.1. Overview

This chapter introduces the API you need to load processes and execute them. For more detail on how to define the processes themselves, check out the chapter on BPMN 2.0.

To interact with the process engine (for example, to start a process), you need to set up a session. This session will be used to communicate with the process engine. A session needs to have a reference to a knowledge base, which contains a reference to all the relevant process definitions. This knowledge base is used to look up the process definitions whenever necessary. To create a session, you first need to create a knowledge base, load all the necessary process definitions (this can be from various sources, like from classpath, file system or process repository) and then instantiate a session.

Once you have set up a session, you can use it to start executing processes. Whenever a process is started, a new process instance is created (for that process definition) that maintains the state of that specific instance of the process.

KnowledgeBaseAndSession

For example, imagine you are writing an application to process sales orders. You could then define one or more process definitions that define how the order should be processed. When starting up your application, you first need to create a knowledge base that contains those process definitions. You can then create a session based on this knowledge base so that, whenever a new sales order comes in, a new process instance is started for that sales order. That process instance contains the state of the process for that specific sales request.

A knowledge base can be shared across sessions and usually is only created once, at the start of the application (as creating a knowledge base can be rather heavy-weight as it involves parsing and compiling the process definitions). Knowledge bases can be dynamically changed (so you can add or remove processes at runtime).

Sessions can be created based on a knowledge base and are used to execute processes and interact with the engine. You can create as many independent session as you need and creating a session is considered relatively lightweight. How many sessions you create is up to you. In general, most simple cases start out with creating one session that is then called from various places in your application. You could decide to create multiple sessions if for example you want to have multiple independent processing units (for example, if you want all processes from one customer to be completely independent from processes for another customer, you could create an independent session for each customer) or if you need multiple sessions for scalability reasons. If you don’t know what to do, simply start by having one knowledge base that contains all your process definitions and create one session that you then use to execute all your processes.

The jBPM project has a clear separation between the API the users should be interacting with and the actual implementation classes. The public API exposes most of the features we believe "normal" users can safely use and should remain rather stable across releases. Expert users can still access internal classes but should be aware that they should know what they are doing and that the internal API might still change in the future.

As explained above, the jBPM API should thus be used to (1) create a knowledge base that contains your process definitions, and to (2) create a session to start new process instances, signal existing ones, register listeners, etc.

6.2. KieBase

The jBPM API allows you to first create a knowledge base. This knowledge base should include all your process definitions that might need to be executed by that session. To create a knowledge base, use a KieHelper to load processes from various resources (for example from the classpath or from the file system), and then create a new knowledge base from that helper. The following code snippet shows how to create a knowledge base consisting of only one process definition (using in this case a resource from the classpath).

  KieHelper kieHelper = new KieHelper();
  KieBase kieBase = kieHelper
                    .addResource(ResourceFactory.newClassPathResource("MyProcess.bpmn"))
                    .build();

The ResourceFactory has similar methods to load files from file system, from URL, InputStream, Reader, etc.

This is considered manual creation of knowledge base and while it is simple it is not recommended for real application development but more for try outs. Following you’ll find recommended and much more powerful way of building knowledge base, knowledge session and more - RuntimeManager.

6.3. KieSession

Once you’ve loaded your knowledge base, you should create a session to interact with the engine. This session can then be used to start new processes, signal events, etc. The following code snippet shows how easy it is to create a session based on the previously created knowledge base, and to start a process (by id).

KieSession ksession = kbase.newKieSession();
ProcessInstance processInstance = ksession.startProcess("com.sample.MyProcess");

6.3.1. ProcessRuntime

The ProcessRuntime interface defines all the session methods for interacting with processes, as shown below.

  /**
	 * Start a new process instance.  The process (definition) that should
	 * be used is referenced by the given process id.
	 *
	 * @param processId  The id of the process that should be started
	 * @return the ProcessInstance that represents the instance of the process that was started
	 */
    ProcessInstance startProcess(String processId);

    /**
	 * Start a new process instance.  The process (definition) that should
	 * be used is referenced by the given process id.  Parameters can be passed
	 * to the process instance (as name-value pairs), and these will be set
	 * as variables of the process instance.
     *
	 * @param processId  the id of the process that should be started
     * @param parameters  the process variables that should be set when starting the process instance
	 * @return the ProcessInstance that represents the instance of the process that was started
     */
    ProcessInstance startProcess(String processId,
                                 Map<String, Object> parameters);

    /**
     * Signals the engine that an event has occurred. The type parameter defines
     * which type of event and the event parameter can contain additional information
     * related to the event.  All process instances that are listening to this type
     * of (external) event will be notified.  For performance reasons, this type of event
     * signaling should only be used if one process instance should be able to notify
     * other process instances. For internal event within one process instance, use the
     * signalEvent method that also include the processInstanceId of the process instance
     * in question.
     *
     * @param type the type of event
     * @param event the data associated with this event
     */
    void signalEvent(String type,
                     Object event);

    /**
     * Signals the process instance that an event has occurred. The type parameter defines
     * which type of event and the event parameter can contain additional information
     * related to the event.  All node instances inside the given process instance that
     * are listening to this type of (internal) event will be notified.  Note that the event
     * will only be processed inside the given process instance.  All other process instances
     * waiting for this type of event will not be notified.
     *
     * @param type the type of event
     * @param event the data associated with this event
     * @param processInstanceId the id of the process instance that should be signaled
     */
    void signalEvent(String type,
                     Object event,
                     long processInstanceId);

    /**
     * Returns a collection of currently active process instances.  Note that only process
     * instances that are currently loaded and active inside the engine will be returned.
     * When using persistence, it is likely not all running process instances will be loaded
     * as their state will be stored persistently.  It is recommended not to use this
     * method to collect information about the state of your process instances but to use
     * a history log for that purpose.
     *
     * @return a collection of process instances currently active in the session
     */
    Collection<ProcessInstance> getProcessInstances();

    /**
     * Returns the process instance with the given id.  Note that only active process instances
     * will be returned.  If a process instance has been completed already, this method will return
     * null.
     *
     * @param id the id of the process instance
     * @return the process instance with the given id or null if it cannot be found
     */
    ProcessInstance getProcessInstance(long processInstanceId);

    /**
     * Aborts the process instance with the given id.  If the process instance has been completed
     * (or aborted), or the process instance cannot be found, this method will throw an
     * IllegalArgumentException.
     *
     * @param id the id of the process instance
     */
    void abortProcessInstance(long processInstanceId);

    /**
     * Returns the WorkItemManager related to this session.  This can be used to
     * register new WorkItemHandlers or to complete (or abort) WorkItems.
     *
     * @return the WorkItemManager related to this session
     */
    WorkItemManager getWorkItemManager();

6.3.2. Event Listeners

The session provides methods for registering and removing listeners. A ProcessEventListener can be used to listen to process-related events, like starting or completing a process, entering and leaving a node, etc. Below, the different methods of the ProcessEventListener class are shown. An event object provides access to related information, like the process instance and node instance linked to the event. You can use this API to register your own event listeners.

public interface ProcessEventListener {

  void beforeProcessStarted( ProcessStartedEvent event );
  void afterProcessStarted( ProcessStartedEvent event );
  void beforeProcessCompleted( ProcessCompletedEvent event );
  void afterProcessCompleted( ProcessCompletedEvent event );
  void beforeNodeTriggered( ProcessNodeTriggeredEvent event );
  void afterNodeTriggered( ProcessNodeTriggeredEvent event );
  void beforeNodeLeft( ProcessNodeLeftEvent event );
  void afterNodeLeft( ProcessNodeLeftEvent event );
  void beforeVariableChanged(ProcessVariableChangedEvent event);
  void afterVariableChanged(ProcessVariableChangedEvent event);

}

A note about before and after events: these events typically act like a stack, which means that any events that occur as a direct result of the previous event, will occur between the before and the after of that event. For example, if a subsequent node is triggered as result of leaving a node, the node triggered events will occur inbetween the beforeNodeLeftEvent and the afterNodeLeftEvent of the node that is left (as the triggering of the second node is a direct result of leaving the first node). Doing that allows us to derive cause relationships between events more easily. Similarly, all node triggered and node left events that are the direct result of starting a process will occur between the beforeProcessStarted and afterProcessStarted events. In general, if you just want to be notified when a particular event occurs, you should be looking at the before events only (as they occur immediately before the event actually occurs). When only looking at the after events, one might get the impression that the events are fired in the wrong order, but because the after events are triggered as a stack (after events will only fire when all events that were triggered as a result of this event have already fired). After events should only be used if you want to make sure that all processing related to this has ended (for example, when you want to be notified when starting of a particular process instance has ended.

Also note that not all nodes always generate node triggered and/or node left events. Depending on the type of node, some nodes might only generate node left events, others might only generate node triggered events. Catching intermediate events for example are not generating triggered events (they are only generating left events, as they are not really triggered by another node, rather activated from outside). Similarly, throwing intermediate events are not generating left events (they are only generating triggered events, as they are not really left, as they have no outgoing connection).

jBPM out-of-the-box provides a listener that can be used to create an audit log (either to the console or the a file on the file system). This audit log contains all the different events that occurred at runtime so it’s easy to figure out what happened. Note that these loggers should only be used for debugging purposes. The following logger implementations are supported by default:

  1. Console logger: This logger writes out all the events to the console.

  2. File logger: This logger writes out all the events to a file using an XML representation. This log file might then be used in the IDE to generate a tree-based visualization of the events that occurred during execution.

  3. Threaded file logger: Because a file logger writes the events to disk only when closing the logger or when the number of events in the logger reaches a predefined level, it cannot be used when debugging processes at runtime. A threaded file logger writes the events to a file after a specified time interval, making it possible to use the logger to visualize the progress in realtime, while debugging processes.

The KieServices lets you add a KieRuntimeLogger to your session, as shown below. When creating a console logger, the knowledge session for which the logger needs to be created must be passed as an argument. The file logger also requires the name of the log file to be created, and the threaded file logger requires the interval (in milliseconds) after which the events should be saved. You should always close the logger at the end of your application.

  import org.kie.api.KieServices;
  import org.kie.api.logger.KieRuntimeLogger;
  ...
  KieRuntimeLogger logger = KieServices.Factory.get().getLoggers().newFileLogger(ksession, "test");
  // add invocations to the process engine here,
  // e.g. ksession.startProcess(processId);
  ...
  logger.close();

The log file that is created by the file-based loggers contains an XML-based overview of all the events that occurred at runtime. It can be opened in Eclipse, using the Audit View in the Drools Eclipse plugin, where the events are visualized as a tree. Events that occur between the before and after event are shown as children of that event. The following screenshot shows a simple example, where a process is started, resulting in the activation of the Start node, an Action node and an End node, after which the process was completed.

AuditView

6.3.3. Correlation Keys

A common requirement when working with processes is ability to assign a given process instance some sort of business identifier that can be later on referenced without knowing the actual (generated) id of the process instance. To provide such capabilities, jBPM allows to use CorrelationKey that is composed of CorrelationProperties. CorrelationKey can have either single property describing it (which is in most cases) but it can be represented as multi valued properties set.

Correlation capabilities are provided as part of interface

CorrelationAwareProcessRuntime

that exposes following methods:

      /**
      * Start a new process instance.  The process (definition) that should
      * be used is referenced by the given process id.  Parameters can be passed
      * to the process instance (as name-value pairs), and these will be set
      * as variables of the process instance.
      *
      * @param processId  the id of the process that should be started
      * @param correlationKey custom correlation key that can be used to identify process instance
      * @param parameters  the process variables that should be set when starting the process instance
      * @return the ProcessInstance that represents the instance of the process that was started
      */
      ProcessInstance startProcess(String processId, CorrelationKey correlationKey, Map<String, Object> parameters);

      /**
      * Creates a new process instance (but does not yet start it).  The process
      * (definition) that should be used is referenced by the given process id.
      * Parameters can be passed to the process instance (as name-value pairs),
      * and these will be set as variables of the process instance.  You should only
      * use this method if you need a reference to the process instance before actually
      * starting it.  Otherwise, use startProcess.
      *
      * @param processId  the id of the process that should be started
      * @param correlationKey custom correlation key that can be used to identify process instance
      * @param parameters  the process variables that should be set when creating the process instance
      * @return the ProcessInstance that represents the instance of the process that was created (but not yet started)
      */
      ProcessInstance createProcessInstance(String processId, CorrelationKey correlationKey, Map<String, Object> parameters);

      /**
      * Returns the process instance with the given correlationKey.  Note that only active process instances
      * will be returned.  If a process instance has been completed already, this method will return
      * null.
      *
      * @param correlationKey the custom correlation key assigned when process instance was created
      * @return the process instance with the given id or null if it cannot be found
      */
      ProcessInstance getProcessInstance(CorrelationKey correlationKey);

Correlation is usually used with long running processes and thus require persistence to be enabled to be able to permanently store correlation information.

6.3.4. Threads

In the following text, we will refer to two types of "multi-threading": logical and technical. Technical multi-threading is what happens when multiple threads or processes are started on a computer, for example by a Java or C program. Logical multi-threading is what we see in a BPM process after the process reaches a parallel gateway, for example. From a functional standpoint, the original process will then split into two processes that are executed in a parallel fashion.

Of course, the jBPM engine supports logical multi-threading: for example, processes that include a parallel gateway. We’ve chosen to implement logical multi-threading using one thread: a jBPM process that includes logical multi-threading will only be executed in one technical thread. The main reason for doing this is that multiple (technical) threads need to be be able to communicate state information with each other if they are working on the same process. This requirement brings with it a number of complications. While it might seem that multi-threading would bring performance benefits with it, the extra logic needed to make sure the different threads work together well means that this is not guaranteed. There is also the extra overhead incurred because we need to avoid race conditions and deadlocks.

In general, the jBPM engine executes actions in serial. For example, when the engine encounters a script task in a process, it will synchronously execute that script and wait for it to complete before continuing execution. Similarly, if a process encounters a parallel gateway, it will sequentially trigger each of the outgoing branches, one after the other. This is possible since execution is almost always instantaneous, meaning that it is extremely fast and produces almost no overhead. As a result, the user will usually not even notice this. Similarly, action scripts in a process are also synchronously executed, and the engine will wait for them to finish before continuing the process. For example, doing a Thread.sleep(…​) as part of a script will not make the engine continue execution elsewhere but will block the engine thread during that period.

The same principle applies to service tasks. When a service task is reached in a process, the engine will also invoke the handler of this service synchronously. The engine will wait for the completeWorkItem(…​) method to return before continuing execution. It is important that your service handler executes your service asynchronously if its execution is not instantaneous.

An example of this would be a service task that invokes an external service. Since the delay in invoking this service remotely and waiting for the results might be too long, it might be a good idea to invoke this service asynchronously. This means that the handler will only invoke the service and will notify the engine later when the results are available. In the mean time, the process engine then continues execution of the process.

Human tasks are a typical example of a service that needs to be invoked asynchronously, as we don’t want the engine to wait until a human actor has responded to the request. The human task handler will only create a new task (on the task list of the assigned actor) when the human task node is triggered. The engine will then be able to continue execution on the rest of the process (if necessary) and the handler will notify the engine asynchronously when the user has completed the task.

6.4. RuntimeManager

6.4.1. Overview

RuntimeManager has been introduced to simplify and empower usage of knowledge API especially in context of processes. It provides configurable strategies that control actual runtime execution (how KieSessions are provided) and by default provides following:

  • Singleton - runtime manager maintains single KieSession regardless of number of processes available

  • Per Request - runtime manager delivers new KieSession for every request

  • Per Process Instance - runtime manager maintains mapping between process instance and KieSession and always provides same KieSession whenever working with given process instance

Runtime Manager is primarily responsible for managing and delivering instances of RuntimeEngine to the caller. In turn, RuntimeEngine encapsulates two the most important elements of jBPM engine:

  • KieSession

  • TaskService

Both of these components are already configured to work with each other smoothly without additional configuration from end user. No more need to register human task handler or keeping track if it’s connected to the service or not.

public interface RuntimeManager {

	/**
	 * Returns <code>RuntimeEngine</code> instance that is fully initialized:
	 * <ul>
	 * 	<li>KiseSession is created or loaded depending on the strategy</li>
	 * 	<li>TaskService is initialized and attached to ksession (via listener)</li>
	 * 	<li>WorkItemHandlers are initialized and registered on ksession</li>
	 * 	<li>EventListeners (process, agenda, working memory) are initialized and added to ksession</li>
	 * </ul>
	 * @param context the concrete implementation of the context that is supported by given <code>RuntimeManager</code>
	 * @return instance of the <code>RuntimeEngine</code>
	 */
    RuntimeEngine getRuntimeEngine(Context<?> context);

    /**
     * Unique identifier of the <code>RuntimeManager</code>
     * @return
     */
    String getIdentifier();

    /**
     * Disposes <code>RuntimeEngine</code> and notifies all listeners about that fact.
     * This method should always be used to dispose <code>RuntimeEngine</code> that is not needed
     * anymore. <br/>
     * ksession.dispose() shall never be used with RuntimeManager as it will break the internal
     * mechanisms of the manager responsible for clear and efficient disposal.<br/>
     * Dispose is not needed if <code>RuntimeEngine</code> was obtained within active JTA transaction,
     * this means that when getRuntimeEngine method was invoked during active JTA transaction then dispose of
     * the runtime engine will happen automatically on transaction completion.
     * @param runtime
     */
    void disposeRuntimeEngine(RuntimeEngine runtime);

    /**
     * Closes <code>RuntimeManager</code> and releases its resources. Shall always be called when
     * runtime manager is not needed any more. Otherwise it will still be active and operational.
     */
    void close();

}

RuntimeEngine interface provides the most important methods to get access to engine components:

public interface RuntimeEngine {

	/**
	 * Returns <code>KieSession</code> configured for this <code>RuntimeEngine</code>
	 * @return
	 */
    KieSession getKieSession();

    /**
	 * Returns <code>TaskService</code> configured for this <code>RuntimeEngine</code>
	 * @return
	 */
    TaskService getTaskService();
}

RuntimeManager will ensure that regardless of the strategy it will provide same capabilities when it comes to initialization and configuration of the RuntimeEngine. That means

  • KieSession will be loaded with same factories (either in memory or JPA based)

  • WorkItemHandlers will be registered on every KieSession (either loaded from db or newly created)

  • Event listeners (Process, Agenda, WorkingMemory) will be registered on every KieSession (either loaded from db or newly created)

  • TaskService will be configured with:

    • JTA transaction manager

    • same entity manager factory as for the KieSession

    • UserGroupCallback from environment

On the other hand, RuntimeManager maintains the engine disposal as well by providing dedicated methods to dispose RuntimeEngine when it’s no more needed to release any resources it might have acquired.

RuntimeManager’s identifier is used as "deploymentId" during runtime execution. For example, the identifier is persisted as "deploymentId" of a Task when the Task is persisted. Task’s deploymentId is used to associate the RuntimeManager when the Task is completed and its process instance is resumed. The deploymentId is also persisted as "externalId" in history log tables. If you don’t specify an identifier on RuntimeManager creation, a default value is applied (e.g. "default-per-pinstance" for PerProcessInstanceRuntimeManager). That means your application uses the same deployment in its lifecycle. If you maintain multiple RuntimeManagers in your application, you need to specify their identifiers. For example, jbpm-services (DeploymentService) maintains multiple RuntimeManagers with identifiers of kjar’s GAV. kie-workbench web application too because it depends on jbpm-services.

6.4.2. Strategies

Singleton strategy - instructs RuntimeManager to maintain single instance of RuntimeEngine (and in turn single instance of KieSession and TaskService). Access to the RuntimeEngine is synchronized and by that thread safe although it comes with a performance penalty due to synchronization. This strategy is similar to what was available by default in jBPM version 5.x and it’s considered easiest strategy and recommended to start with.

It has following characteristics that are important to evaluate while considering it for given scenario:

  • small memory footprint - single instance of runtime engine and task service

  • simple and compact in design and usage

  • good fit for low to medium load on process engine due to synchronized access

  • due to single KieSession instance all state objects (such as facts) are directly visible to all process instances and vice versa

  • not contextual - meaning when retrieving instances of RuntimeEngine from singleton RuntimeManager Context instance is not important and usually EmptyContext.get() is used although null argument is acceptable as well

  • keeps track of id of KieSession used between RuntimeManager restarts to ensure it will use same session - this id is stored as serialized file on disc in temp location that depends on the environment can be one of following:

    • value given by jbpm.data.dir system property

    • value given by jboss.server.data.dir system property

    • value given by java.io.tmpdir system property

Per request strategy - instructs RuntimeManager to provide new instance of RuntimeEngine for every request. As request RuntimeManager will consider one or more invocations within single transaction. It must return same instance of RuntimeEngine within single transaction to ensure correctness of state as otherwise operation done in one call would not be visible in the other. This is sort of "stateless" strategy that provides only request scope state and once request is completed RuntimeEngine will be permanently destroyed - KieSession information will be removed from the database in case persistence was used.

It has following characteristics:

  • completely isolated process engine and task service operations for every request

  • completely stateless, storing facts makes sense only for the duration of the request

  • good fit for high load, stateless processes (no facts or timers involved that shall be preserved between requests)

  • KieSession is only available during life time of request and at the end is destroyed

  • not contextual - meaning when retrieving instances of RuntimeEngine from per request RuntimeManager Context instance is not important and usually EmptyContext.get() is used although null argument is acceptable as well

Per process instance strategy - instructs RuntimeManager to maintain a strict relationship between KieSession and ProcessInstance. That means that KieSession will be available as long as the ProcessInstance that it belongs to is active. This strategy provides the most flexible approach to use advanced capabilities of the engine like rule evaluation in isolation (for given process instance only), maximum performance and reduction of potential bottlenecks intriduced by synchronization; and at the same time reduces number of KieSessions to the actual number of process instances rather than number of requests (in contrast to per request strategy).

It has following characteristics:

  • most advanced strategy to provide isolation to given process instance only

  • maintains strict relationship between KieSession and ProcessInstance to ensure it will always deliver same KieSession for given ProcessInstance

  • merges life cycle of KieSession with ProcessInstance making both to be disposed on process instance completion (complete or abort)

  • allows to maintain data (such as facts, timers) in scope of process instance - only process instance will have access to that data

  • introduces bit of overhead due to need to look up and load KieSession for process instance

  • validates usage of KieSession so it cannot be (ab)used for other process instances, in such case an exception is thrown

  • is contextual - accepts following context instances:

    • EmptyContext or null - when starting process instance as there is no process instance id available yet

    • ProcessInstanceIdContext - used after process instance was created

    • CorrelationKeyContext - used as an alternative to ProcessInstanceIdContext to use custom (business) key instead of process instance id

6.4.3. Usage

Regular usage scenario for RuntimeManager is:

  • At application startup

    • build RuntimeManager and keep it for entire life time of the application, it’s thread safe and can be (or even should be) accessed concurrently

  • At request

    • get RuntimeEngine from RuntimeManager using proper context instance dedicated to strategy of RuntimeManager

    • get KieSession and/or TaskService from RuntimeEngine

    • perform operations on KieSession and/or TaskService such as startProcess, completeTask, etc

    • once done with processing dispose RuntimeEngine using RuntimeManager.disposeRuntimeEngine method

  • At application shutdown

    • close RuntimeManager

When RuntimeEngine is obtained from RuntimeManager within an active JTA transaction, then there is no need to dispose RuntimeEngine at the end, as RuntimeManager will automatically dispose the RuntimeEngine on transaction completion (regardless of the completion status commit or rollback).

6.4.3.1. Example

Here is how you can build RuntimeManager and get RuntimeEngine (that encapsulates KieSession and TaskService) from it:

    // first configure environment that will be used by RuntimeManager
    RuntimeEnvironment environment = RuntimeEnvironmentBuilder.Factory.get()
    .newDefaultInMemoryBuilder()
    .addAsset(ResourceFactory.newClassPathResource("BPMN2-ScriptTask.bpmn2"), ResourceType.BPMN2)
    .get();

    // next create RuntimeManager - in this case singleton strategy is chosen
    RuntimeManager manager = RuntimeManagerFactory.Factory.get().newSingletonRuntimeManager(environment);

    // then get RuntimeEngine out of manager - using empty context as singleton does not keep track
    // of runtime engine as there is only one
    RuntimeEngine runtime = manager.getRuntimeEngine(EmptyContext.get());

    // get KieSession from runtime runtimeEngine - already initialized with all handlers, listeners, etc that were configured
    // on the environment
    KieSession ksession = runtimeEngine.getKieSession();

    // add invocations to the process engine here,
    // e.g. ksession.startProcess(processId);

    // and last dispose the runtime engine
    manager.disposeRuntimeEngine(runtimeEngine);

This example provides simplest (minimal) way of using RuntimeManager and RuntimeEngine although it provides few quite valuable information:

  • KieSession will be in memory only - by using newDefaultInMemoryBuilder

  • there will be single process available for execution - by adding it as an asset

  • TaskService will be configured and attached to KieSession via LocalHTWorkItemHandler to support user task capabilities within processes

6.4.4. Configuration

The complexity of knowing when to create, dispose, register handlers, etc is taken away from the end user and moved to the runtime manager that knows when/how to perform such operations but still allows to have a fine grained control over this process by providing comprehensive configuration of the RuntimeEnvironment.

  public interface RuntimeEnvironment {

	/**
	 * Returns <code>KieBase</code> that shall be used by the manager
	 * @return
	 */
    KieBase getKieBase();

    /**
     * KieSession environment that shall be used to create instances of <code>KieSession</code>
     * @return
     */
    Environment getEnvironment();

    /**
     * KieSession configuration that shall be used to create instances of <code>KieSession</code>
     * @return
     */
    KieSessionConfiguration getConfiguration();

    /**
     * Indicates if persistence shall be used for the KieSession instances
     * @return
     */
    boolean usePersistence();

    /**
     * Delivers concrete implementation of <code>RegisterableItemsFactory</code> to obtain handlers and listeners
     * that shall be registered on instances of <code>KieSession</code>
     * @return
     */
    RegisterableItemsFactory getRegisterableItemsFactory();

    /**
     * Delivers concrete implementation of <code>UserGroupCallback</code> that shall be registered on instances
     * of <code>TaskService</code> for managing users and groups.
     * @return
     */
    UserGroupCallback getUserGroupCallback();

    /**
     * Delivers custom class loader that shall be used by the process engine and task service instances
     * @return
     */
    ClassLoader getClassLoader();

    /**
     * Closes the environment allowing to close all depending components such as ksession factories, etc
     */
    void close();
6.4.4.1. Building RuntimeEnvironment

While RuntimeEnvironment interface provides mostly access to data kept as part of the environment and will be used by the RuntimeManager, users should take advantage of builder style class that provides fluent API to configure RuntimeEnvironment with predefined settings.

public interface RuntimeEnvironmentBuilder {

	public RuntimeEnvironmentBuilder persistence(boolean persistenceEnabled);

	public RuntimeEnvironmentBuilder entityManagerFactory(Object emf);

	public RuntimeEnvironmentBuilder addAsset(Resource asset, ResourceType type);

	public RuntimeEnvironmentBuilder addEnvironmentEntry(String name, Object value);

	public RuntimeEnvironmentBuilder addConfiguration(String name, String value);

	public RuntimeEnvironmentBuilder knowledgeBase(KieBase kbase);

	public RuntimeEnvironmentBuilder userGroupCallback(UserGroupCallback callback);

	public RuntimeEnvironmentBuilder registerableItemsFactory(RegisterableItemsFactory factory);

	public RuntimeEnvironment get();

	public RuntimeEnvironmentBuilder classLoader(ClassLoader cl);

	public RuntimeEnvironmentBuilder schedulerService(Object globalScheduler);

Instances of the RuntimeEnvironmentBuilder can be obtained via RuntimeEnvironmentBuilderFactory that provides preconfigured sets of builder to simplify and help users to build the environment for the RuntimeManager.

public interface RuntimeEnvironmentBuilderFactory {

	/**
     * Provides completely empty <code>RuntimeEnvironmentBuilder</code> instance that allows to manually
     * set all required components instead of relying on any defaults.
     * @return new instance of <code>RuntimeEnvironmentBuilder</code>
     */
    public RuntimeEnvironmentBuilder newEmptyBuilder();

    /**
     * Provides default configuration of <code>RuntimeEnvironmentBuilder</code> that is based on:
     * <ul>
     * 	<li>DefaultRuntimeEnvironment</li>
     * </ul>
     * @return new instance of <code>RuntimeEnvironmentBuilder</code> that is already preconfigured with defaults
     *
     * @see DefaultRuntimeEnvironment
     */
    public RuntimeEnvironmentBuilder newDefaultBuilder();

    /**
     * Provides default configuration of <code>RuntimeEnvironmentBuilder</code> that is based on:
     * <ul>
     * 	<li>DefaultRuntimeEnvironment</li>
     * </ul>
     * but it does not have persistence for process engine configured so it will only store process instances in memory
     * @return new instance of <code>RuntimeEnvironmentBuilder</code> that is already preconfigured with defaults
     *
     * @see DefaultRuntimeEnvironment
     */
    public RuntimeEnvironmentBuilder newDefaultInMemoryBuilder();

    /**
     * Provides default configuration of <code>RuntimeEnvironmentBuilder</code> that is based on:
     * <ul>
     * 	<li>DefaultRuntimeEnvironment</li>
     * </ul>
     * This one is tailored to works smoothly with kjars as the notion of kbase and ksessions
     * @param groupId group id of kjar
     * @param artifactId artifact id of kjar
     * @param version version number of kjar
     * @return new instance of <code>RuntimeEnvironmentBuilder</code> that is already preconfigured with defaults
     *
     * @see DefaultRuntimeEnvironment
     */
    public RuntimeEnvironmentBuilder newDefaultBuilder(String groupId, String artifactId, String version);

    /**
     * Provides default configuration of <code>RuntimeEnvironmentBuilder</code> that is based on:
     * <ul>
     * 	<li>DefaultRuntimeEnvironment</li>
     * </ul>
     * This one is tailored to works smoothly with kjars as the notion of kbase and ksessions
     * @param groupId group id of kjar
     * @param artifactId artifact id of kjar
     * @param version version number of kjar
     * @param kbaseName name of the kbase defined in kmodule.xml stored in kjar
     * @param ksessionName name of the ksession define in kmodule.xml stored in kjar
     * @return new instance of <code>RuntimeEnvironmentBuilder</code> that is already preconfigured with defaults
     *
     * @see DefaultRuntimeEnvironment
     */
    public RuntimeEnvironmentBuilder newDefaultBuilder(String groupId, String artifactId, String version, String kbaseName, String ksessionName);

    /**
     * Provides default configuration of <code>RuntimeEnvironmentBuilder</code> that is based on:
     * <ul>
     * 	<li>DefaultRuntimeEnvironment</li>
     * </ul>
     * This one is tailored to works smoothly with kjars as the notion of kbase and ksessions
     * @param releaseId <code>ReleaseId</code> that described the kjar
     * @return new instance of <code>RuntimeEnvironmentBuilder</code> that is already preconfigured with defaults
     *
     * @see DefaultRuntimeEnvironment
     */
    public RuntimeEnvironmentBuilder newDefaultBuilder(ReleaseId releaseId);

    /**
     * Provides default configuration of <code>RuntimeEnvironmentBuilder</code> that is based on:
     * <ul>
     * 	<li>DefaultRuntimeEnvironment</li>
     * </ul>
     * This one is tailored to works smoothly with kjars as the notion of kbase and ksessions
     * @param releaseId <code>ReleaseId</code> that described the kjar
     * @param kbaseName name of the kbase defined in kmodule.xml stored in kjar
     * @param ksessionName name of the ksession define in kmodule.xml stored in kjar
     * @return new instance of <code>RuntimeEnvironmentBuilder</code> that is already preconfigured with defaults
     *
     * @see DefaultRuntimeEnvironment
     */
    public RuntimeEnvironmentBuilder newDefaultBuilder(ReleaseId releaseId, String kbaseName, String ksessionName);

    /**
     * Provides default configuration of <code>RuntimeEnvironmentBuilder</code> that is based on:
     * <ul>
     * 	<li>DefaultRuntimeEnvironment</li>
     * </ul>
     * It relies on KieClasspathContainer that requires to have kmodule.xml present in META-INF folder which
     * defines the kjar itself.
     * Expects to use default kbase and ksession from kmodule.
     * @return new instance of <code>RuntimeEnvironmentBuilder</code> that is already preconfigured with defaults
     *
     * @see DefaultRuntimeEnvironment
     */
    public RuntimeEnvironmentBuilder newClasspathKmoduleDefaultBuilder();

    /**
     * Provides default configuration of <code>RuntimeEnvironmentBuilder</code> that is based on:
     * <ul>
     * 	<li>DefaultRuntimeEnvironment</li>
     * </ul>
     * It relies on KieClasspathContainer that requires to have kmodule.xml present in META-INF folder which
     * defines the kjar itself.
     * @param kbaseName name of the kbase defined in kmodule.xml
     * @param ksessionName name of the ksession define in kmodule.xml
     * @return new instance of <code>RuntimeEnvironmentBuilder</code> that is already preconfigured with defaults
     *
     * @see DefaultRuntimeEnvironment
     */
    public RuntimeEnvironmentBuilder newClasspathKmoduleDefaultBuilder(String kbaseName, String ksessionName);

Besides KieSession Runtime Manager provides access to TaskService too as integrated component of a RuntimeEngine that will always be configured and ready for communication between process engine and task service.

Since the default builder was used, it will already come with predefined set of elements that consists of:

  • Persistence unit name will be set to org.jbpm.persistence.jpa (for both process engine and task service)

  • Human Task handler will be automatically registered on KieSession

  • JPA based history log event listener will be automatically registered on KieSession

  • Event listener to trigger rule task evaluation (fireAllRules) will be automatically registered on KieSession

6.4.4.2. Registering handlers and listeners

To extend it with your own handlers or listeners a dedicated mechanism is provided that comes as implementation of RegisterableItemsFactory

	/**
	 * Returns new instances of <code>WorkItemHandler</code> that will be registered on <code>RuntimeEngine</code>
	 * @param runtime provides <code>RuntimeEngine</code> in case handler need to make use of it internally
	 * @return map of handlers to be registered - in case of no handlers empty map shall be returned.
	 */
    Map<String, WorkItemHandler> getWorkItemHandlers(RuntimeEngine runtime);

    /**
	 * Returns new instances of <code>ProcessEventListener</code> that will be registered on <code>RuntimeEngine</code>
	 * @param runtime provides <code>RuntimeEngine</code> in case listeners need to make use of it internally
	 * @return list of listeners to be registered - in case of no listeners empty list shall be returned.
	 */
    List<ProcessEventListener> getProcessEventListeners(RuntimeEngine runtime);

    /**
	 * Returns new instances of <code>AgendaEventListener</code> that will be registered on <code>RuntimeEngine</code>
	 * @param runtime provides <code>RuntimeEngine</code> in case listeners need to make use of it internally
	 * @return list of listeners to be registered - in case of no listeners empty list shall be returned.
	 */
    List<AgendaEventListener> getAgendaEventListeners(RuntimeEngine runtime);

    /**
	 * Returns new instances of <code>WorkingMemoryEventListener</code> that will be registered on <code>RuntimeEngine</code>
	 * @param runtime provides <code>RuntimeEngine</code> in case listeners need to make use of it internally
	 * @return list of listeners to be registered - in case of no listeners empty list shall be returned.
	 */
    List<WorkingMemoryEventListener> getWorkingMemoryEventListeners(RuntimeEngine runtime);

A best practice is to just extend those that come out of the box and just add your own. Extensions are not always needed as the default implementations of RegisterableItemsFactory provides possibility to define custom handlers and listeners. Following is a list of available implementations that might be useful (they are ordered in the hierarchy of inheritance):

  • org.jbpm.runtime.manager.impl.SimpleRegisterableItemsFactory - simplest possible implementations that comes empty and is based on reflection to produce instances of handlers and listeners based on given class names

  • org.jbpm.runtime.manager.impl.DefaultRegisterableItemsFactory - extension of the Simple implementation that introduces defaults described above and still provides same capabilities as Simple implementation

  • org.jbpm.runtime.manager.impl.KModuleRegisterableItemsFactory - extension of default implementation that provides specific capabilities for kmodule and still provides same capabilities as Simple implementation

  • org.jbpm.runtime.manager.impl.cdi.InjectableRegisterableItemsFactory - extension of default implementation that is tailored for CDI environments and provides CDI style approach to finding handlers and listeners via producers

Alternatively, simple (stateless or requiring only KieSession) work item handlers might be registered in the well known way - defined as part of CustomWorkItem.conf file that shall be placed on class path. To use this approach do following:

  • create file "drools.session.conf" inside META-INF of the root of the class path, for web applications it will be WEB-INF/classes/META-INF

  • add following line to drools.session.conf file "drools.workItemHandlers = CustomWorkItemHandlers.conf"

  • create file "CustomWorkItemHandlers.conf" inside META-INF of the root of the class path, for web applications it will be WEB-INF/classes/META-INF

  • define custom work item handlers in MVEL style inside CustomWorkItemHandlers.conf

    [
      "Log": new org.jbpm.process.instance.impl.demo.SystemOutWorkItemHandler(),
      "WebService": new org.jbpm.process.workitem.webservice.WebServiceWorkItemHandler(ksession),
      "Rest": new org.jbpm.process.workitem.rest.RESTWorkItemHandler(),
      "Service Task" : new org.jbpm.process.workitem.bpmn2.ServiceTaskHandler(ksession)
    ]

And that’s it, now all these work item handlers will be registered for any KieSession created by that application, regardless if it uses RuntimeManager or not.

Registering handlers and listeners in CDI environment

When using RuntimeManager in CDI environment there are dedicated interfaces that can be used to provide custom WorkItemHandlers and EventListeners to the RuntimeEngine.

public interface WorkItemHandlerProducer {

    /**
     * Returns map of (key = work item name, value work item handler instance) of work items
     * to be registered on KieSession
     * <br/>
     * Parameters that might be given are as follows:
     * <ul>
     *  <li>ksession</li>
     *  <li>taskService</li>
     *  <li>runtimeManager</li>
     * </ul>
     *
     * @param identifier - identifier of the owner - usually RuntimeManager that allows the producer to filter out
     * and provide valid instances for given owner
     * @param params - owner might provide some parameters, usually KieSession, TaskService, RuntimeManager instances
     * @return map of work item handler instances (recommendation is to always return new instances when this method is invoked)
     */
    Map<String, WorkItemHandler> getWorkItemHandlers(String identifier, Map<String, Object> params);
}

Event listener producer shall be annotated with proper qualifier to indicate what type of listeners they provide, so pick one of following to indicate they type:

  • @Process - for ProcessEventListener

  • @Agenda - for AgendaEventListener

  • @WorkingMemory - for WorkingMemoryEventListener

public interface EventListenerProducer<T> {

    /**
     * Returns list of instances for given (T) type of listeners
     * <br/>
     * Parameters that might be given are as follows:
     * <ul>
     *  <li>ksession</li>
     *  <li>taskService</li>
     *  <li>runtimeManager</li>
     * </ul>
     * @param identifier - identifier of the owner - usually RuntimeManager that allows the producer to filter out
     * and provide valid instances for given owner
     * @param params - owner might provide some parameters, usually KieSession, TaskService, RuntimeManager instances
     * @return list of listener instances (recommendation is to always return new instances when this method is invoked)
     */
    List<T> getEventListeners(String identifier, Map<String, Object>  params);
}

Implementations of these interfaces shall be packaged as bean archive (includes beans.xml inside META-INF) and placed on application classpath (e.g. WEB-INF/lib for web application). THat is enough for CDI based RuntimeManager to discover them and register on every KieSession that is created or loaded from data store.

Some parameters are provided to the producers to allow handlers/listeners to be more stateful and be able to do more advanced things with the engine - like signal of the engine or process instance in case of an error. Thus all components are provided:

  • KieSession

  • TaskService

  • RuntimeManager

Whenever there is a need to interact with the process engine/task service from within handler or listener, recommended approach is to use RuntimeManager and retrieve RuntimeEngine (and then KieSession and/or TaskService) from it as that will ensure proper state managed according to strategy

In addition, some filtering can be applied based on identifier (that is given as argument to the methods) to decide if given RuntimeManager shall receive handlers/listeners or not.

6.5. Services

On top of RuntimeManager API a set of high level services has been provided from jBPM version 6.2. These services are meant to be the easiest way to embed (j)BPM capabilities into custom application. A complete set of modules are delivered as part of these services. They are partitioned into several modules to ease thier adoptions in various environments.

  • jbpm-services-api

    contains only api classes and interfaces

  • jbpm-kie-services

    rewritten code implementation of services api - pure java, no framework dependencies

  • jbpm-services-cdi

    CDI wrapper on top of core services implementation

  • jbpm-services-ejb-api

    extension to services api for ejb needs

  • jbpm-services-ejb-impl

    EJB wrappers on top of core services implementation

  • jbpm-services-ejb-timer

    scheduler service based on EJB TimerService to support time based operations e.g. timer events, deadlines, etc

  • jbpm-services-ejb-client

    EJB remote client implementation - currently only for JBoss Service modules are grouped with its framework dependencies, so developers are free to choose which one is suitable for them and use only that.

6.5.1. Deployment Service

As the name suggest, its primary responsibility is to deploy (and undeploy) units. Deployment unit is kjar that brings in business assets (like processes, rules, forms, data model) for execution. Deployment services allow to query it to get hold of available deployment units and even their RuntimeManager instances.

there are some restrictions on EJB remote client to do not expose RuntimeManager as it won’t make any sense on client side (after it was serialized).

So typical use case for this service is to provide dynamic behavior into your system so multiple kjars can be active at the same time and be executed simultaneously.

// create deployment unit by giving GAV
DeploymentUnit deploymentUnit = new KModuleDeploymentUnit(GROUP_ID, ARTIFACT_ID, VERSION);
// deploy
deploymentService.deploy(deploymentUnit);
// retrieve deployed unit
DeployedUnit deployed = deploymentService.getDeployedUnit(deploymentUnit.getIdentifier());
// get runtime manager
RuntimeManager manager = deployed.getRuntimeManager();

Complete DeploymentService interface is as follows:

public interface DeploymentService {

    void deploy(DeploymentUnit unit);

    void undeploy(DeploymentUnit unit);

    RuntimeManager getRuntimeManager(String deploymentUnitId);

    DeployedUnit getDeployedUnit(String deploymentUnitId);

    Collection<DeployedUnit> getDeployedUnits();

    void activate(String deploymentId);

    void deactivate(String deploymentId);

    boolean isDeployed(String deploymentUnitId);
}

6.5.2. Definition Service

Upon deployment, every process definition is scanned using definition service that parses the process and extracts valuable information out of it. These information can provide valuable input to the system to inform users about what is expected. Definition service provides information about:

  • process definition - id, name, description

  • process variables - name and type

  • reusable subprocesses used in the process (if any)

  • service tasks (domain specific activities)

  • user tasks including assignment information

  • task data input and output information

So definition service can be seen as sort of supporting service that provides quite a few information about process definition that are extracted directly from BPMN2.

String processId = "org.jbpm.writedocument";

Collection<UserTaskDefinition> processTasks =
bpmn2Service.getTasksDefinitions(deploymentUnit.getIdentifier(), processId);

Map<String, String> processData =
bpmn2Service.getProcessVariables(deploymentUnit.getIdentifier(), processId);

Map<String, String> taskInputMappings =
bpmn2Service.getTaskInputMappings(deploymentUnit.getIdentifier(), processId, "Write a Document" );

While it usually is used with combination of other services (like deployment service) it can be used standalone as well to get details about process definition that do not come from kjar. This can be achieved by using buildProcessDefinition method of definition service.

public interface DefinitionService {

    ProcessDefinition buildProcessDefinition(String deploymentId, String bpmn2Content,
			ClassLoader classLoader, boolean cache) throws IllegalArgumentException;

    ProcessDefinition getProcessDefinition(String deploymentId, String processId);

    Collection<String> getReusableSubProcesses(String deploymentId, String processId);

    Map<String, String> getProcessVariables(String deploymentId, String processId);

    Map<String, String> getServiceTasks(String deploymentId, String processId);

    Map<String, Collection<String>> getAssociatedEntities(String deploymentId, String processId);

    Collection<UserTaskDefinition> getTasksDefinitions(String deploymentId, String processId);

    Map<String, String> getTaskInputMappings(String deploymentId, String processId, String taskName);

    Map<String, String> getTaskOutputMappings(String deploymentId, String processId, String taskName);

}

6.5.3. Process Service

Process service is the one that usually is of the most interest. Once the deployment and definition service was already used to feed the system with something that can be executed. Process service provides access to execution environment that allows:

  • start new process instance

  • work with existing one - signal, get details of it, get variables, etc

  • work with work items

At the same time process service is a command executor so it allows to execute commands (essentially on ksession) to extend its capabilities.

Important to note is that process service is focused on runtime operations so use it whenever there is a need to alter (signal, change variables, etc) process instance and not for read operations like show available process instances by looping though given list and invoking getProcessInstance method. For that there is dedicated runtime data service that is described below.

An example on how to deploy and run process can be done as follows:

KModuleDeploymentUnit deploymentUnit = new KModuleDeploymentUnit(GROUP_ID, ARTIFACT_ID, VERSION);

deploymentService.deploy(deploymentUnit);

long processInstanceId = processService.startProcess(deploymentUnit.getIdentifier(), "customtask");

ProcessInstance pi = processService.getProcessInstance(processInstanceId);

As you can see start process expects deploymentId as first argument. This is extremely powerful to enable service to easily work with various deployments, even with same processes but coming from different versions - kjar versions.

public interface ProcessService {

    Long startProcess(String deploymentId, String processId);

    Long startProcess(String deploymentId, String processId, Map<String, Object> params);

    void abortProcessInstance(Long processInstanceId);

    void abortProcessInstances(List<Long> processInstanceIds);

    void signalProcessInstance(Long processInstanceId, String signalName, Object event);

    void signalProcessInstances(List<Long> processInstanceIds, String signalName, Object event);

    ProcessInstance getProcessInstance(Long processInstanceId);

    void setProcessVariable(Long processInstanceId, String variableId, Object value);

    void setProcessVariables(Long processInstanceId, Map<String, Object> variables);

    Object getProcessInstanceVariable(Long processInstanceId, String variableName);

    Map<String, Object> getProcessInstanceVariables(Long processInstanceId);

    Collection<String> getAvailableSignals(Long processInstanceId);

    void completeWorkItem(Long id, Map<String, Object> results);

    void abortWorkItem(Long id);

    WorkItem getWorkItem(Long id);

    List<WorkItem> getWorkItemByProcessInstance(Long processInstanceId);

    public <T> T execute(String deploymentId, Command<T> command);

    public <T> T execute(String deploymentId, Context<?> context, Command<T> command);

}

6.5.4. Runtime Data Service

Runtime data service as name suggests, deals with all that refers to runtime information:

  • started process instances

  • executed node instances

  • executed node instances

  • and more

Use this service as main source of information whenever building list based UI - to show process definitions, process instances, tasks for given user, etc. This service was designed to be as efficient as possible and still provide all required information.

Some examples:

  • get all process definitions

    Collection definitions = runtimeDataService.getProcesses(new QueryContext());
  • get active process instances

    Collection<processinstancedesc> instances = runtimeDataService.getProcessInstances(new QueryContext());
  • get active nodes for given process instance

    Collection<nodeinstancedesc> instances = runtimeDataService.getProcessInstanceHistoryActive(processInstanceId, new QueryContext());
  • get tasks assigned to john

    List<tasksummary> taskSummaries = runtimeDataService.getTasksAssignedAsPotentialOwner("john", new QueryFilter(0, 10));

There are two important arguments that the runtime data service operations supports:

  • QueryContext

  • QueryFilter - extension of QueryContext

These provide capabilities for efficient management result set like pagination, sorting and ordering (QueryContext). Moreover additional filtering can be applied to task queries to provide more advanced capabilities when searching for user tasks.

public interface RuntimeDataService {

    // Process instance information

    Collection<ProcessInstanceDesc> getProcessInstances(QueryContext queryContext);

    Collection<ProcessInstanceDesc> getProcessInstances(List<Integer> states, String initiator, QueryContext queryContext);

    Collection<ProcessInstanceDesc> getProcessInstancesByProcessId(List<Integer> states, String processId, String initiator, QueryContext queryContext);

    Collection<ProcessInstanceDesc> getProcessInstancesByProcessName(List<Integer> states, String processName, String initiator, QueryContext queryContext);

    Collection<ProcessInstanceDesc> getProcessInstancesByDeploymentId(String deploymentId, List<Integer> states, QueryContext queryContext);

    ProcessInstanceDesc getProcessInstanceById(long processInstanceId);

    Collection<ProcessInstanceDesc> getProcessInstancesByProcessDefinition(String processDefId, QueryContext queryContext);

    Collection<ProcessInstanceDesc> getProcessInstancesByProcessDefinition(String processDefId, List<Integer> states, QueryContext queryContext);


    // Node and Variable instance information

    NodeInstanceDesc getNodeInstanceForWorkItem(Long workItemId);

    Collection<NodeInstanceDesc> getProcessInstanceHistoryActive(long processInstanceId, QueryContext queryContext);

    Collection<NodeInstanceDesc> getProcessInstanceHistoryCompleted(long processInstanceId, QueryContext queryContext);

    Collection<NodeInstanceDesc> getProcessInstanceFullHistory(long processInstanceId, QueryContext queryContext);

    Collection<NodeInstanceDesc> getProcessInstanceFullHistoryByType(long processInstanceId, EntryType type, QueryContext queryContext);

    Collection<VariableDesc> getVariablesCurrentState(long processInstanceId);

    Collection<VariableDesc> getVariableHistory(long processInstanceId, String variableId, QueryContext queryContext);


    // Process information

    Collection<ProcessDefinition> getProcessesByDeploymentId(String deploymentId, QueryContext queryContext);

    Collection<ProcessDefinition> getProcessesByFilter(String filter, QueryContext queryContext);

    Collection<ProcessDefinition> getProcesses(QueryContext queryContext);

    Collection<String> getProcessIds(String deploymentId, QueryContext queryContext);

    ProcessDefinition getProcessById(String processId);

    ProcessDefinition getProcessesByDeploymentIdProcessId(String deploymentId, String processId);

	// user task query operations

    UserTaskInstanceDesc getTaskByWorkItemId(Long workItemId);

    UserTaskInstanceDesc getTaskById(Long taskId);

    List<TaskSummary> getTasksAssignedAsBusinessAdministrator(String userId, QueryFilter filter);

    List<TaskSummary> getTasksAssignedAsBusinessAdministratorByStatus(String userId, List<Status> statuses, QueryFilter filter);

    List<TaskSummary> getTasksAssignedAsPotentialOwner(String userId, QueryFilter filter);

    List<TaskSummary> getTasksAssignedAsPotentialOwner(String userId, List<String> groupIds, QueryFilter filter);

    List<TaskSummary> getTasksAssignedAsPotentialOwnerByStatus(String userId, List<Status> status, QueryFilter filter);

    List<TaskSummary> getTasksAssignedAsPotentialOwner(String userId, List<String> groupIds, List<Status> status, QueryFilter filter);

    List<TaskSummary> getTasksAssignedAsPotentialOwnerByExpirationDateOptional(String userId, List<Status> status, Date from, QueryFilter filter);

    List<TaskSummary> getTasksOwnedByExpirationDateOptional(String userId, List<Status> strStatuses, Date from, QueryFilter filter);

    List<TaskSummary> getTasksOwned(String userId, QueryFilter filter);

    List<TaskSummary> getTasksOwnedByStatus(String userId, List<Status> status, QueryFilter filter);

    List<Long> getTasksByProcessInstanceId(Long processInstanceId);

    List<TaskSummary> getTasksByStatusByProcessInstanceId(Long processInstanceId, List<Status> status, QueryFilter filter);

    List<AuditTask> getAllAuditTask(String userId, QueryFilter filter);

}

6.5.5. User Task Service

User task service covers complete life cycle of individual task so it can be managed from start to end. It explicitly eliminates queries from it to provide scoped execution and moves all query operations into runtime data service. Besides lifecycle operations user task service allows:

  • modification of selected properties

  • access to task variables

  • access to task attachments

  • access to task comments

On top of that user task service is a command executor as well that allows to execute custom task commands.

Complete example with start process and complete user task done by services:

long processInstanceId =
processService.startProcess(deployUnit.getIdentifier(), "org.jbpm.writedocument");

List<Long> taskIds =
runtimeDataService.getTasksByProcessInstanceId(processInstanceId);

Long taskId = taskIds.get(0);

userTaskService.start(taskId, "john");
UserTaskInstanceDesc task = runtimeDataService.getTaskById(taskId);

Map<String, Object> results = new HashMap<String, Object>();
results.put("Result", "some document data");
userTaskService.complete(taskId, "john", results);

The most important thing when working with services is that there is no more need to create your own implementations of Process service that simply wraps runtime manager, runtime engine, ksession usage. Services make use of RuntimeManager API best practices and thus eliminate various risks when working with that API.

6.5.6. QueryService

QueryService provides advanced search capabilities that are based on Dashbuilder DataSets. The concept behind it is that users are given control over how to retrieve data from underlying data store. This includes complex joins with external tables such as JPA entities tables, custom systems data base tables etc.

QueryService is build around two parts:

  • Management operations

    • register query definition

    • replace query definition

    • unregister (remove) query definition

    • get query definition

    • get all registered query definitions

  • Runtime operations

    • query - with two flavors

      • simple based on QueryParam as filter provider

      • advanced based on QueryParamBuilder as filter provider

DashBuilder DataSets provide support for multiple data sources (CSV, SQL, elastic search, etc) while jBPM - since its backend is RDBMS based - focuses on SQL based data sets. So jBPM QueryService is a subset of DashBuilder DataSets capabilities to allow efficient queries with simple API.

Terminology

  • QueryDefinition - represents definion of the data set which consists of unique name, sql expression (the query) and source - JNDI name of the data source to use when performing queries

  • QueryParam - basic structure that represents individual query parameter - condition - that consists of: column name, operator, expected value(s)

  • QueryResultMapper - responsible for mapping raw data set data (rows and columns) into object representation

  • QueryParamBuilder - responsible for building query filters that will be applied on the query definition for given query invocation

While QueryDefinition and QueryParam is rather straight forward, QueryParamBuilder and QueryResultMapper is bit more advanced and require slightly more attention to make use of it in right way, and by that take advantage of their capabilities.

QueryResultMapper

Mapper as the name suggest, maps data taken out from data base (from data set) into object representation. Much like ORM providers such as hibernate maps tables to entities. Obviously there might be many object types that could be used for representing data set results so it’s almost impossible to provide them out of the box. Mappers are rather powerful and thus are pluggable, you can implement your own that will transform the result into whatever type you like. jBPM comes with following mappers out of the box:

  • org.jbpm.kie.services.impl.query.mapper.ProcessInstanceQueryMapper

    • registered with name - ProcessInstances

  • org.jbpm.kie.services.impl.query.mapper.ProcessInstanceWithVarsQueryMapper

    • registered with name - ProcessInstancesWithVariables

  • org.jbpm.kie.services.impl.query.mapper.ProcessInstanceWithCustomVarsQueryMapper

    • registered with name - ProcessInstancesWithCustomVariables

  • org.jbpm.kie.services.impl.query.mapper.UserTaskInstanceQueryMapper

    • registered with name - UserTasks

  • org.jbpm.kie.services.impl.query.mapper.UserTaskInstanceWithVarsQueryMapper

    • registered with name - UserTasksWithVariables

  • org.jbpm.kie.services.impl.query.mapper.UserTaskInstanceWithCustomVarsQueryMapper

    • registered with name - UserTasksWithCustomVariables

  • org.jbpm.kie.services.impl.query.mapper.TaskSummaryQueryMapper

    • registered with name - TaskSummaries

  • org.jbpm.kie.services.impl.query.mapper.RawListQueryMapper

    • registered with name - RawList

Each QueryResultMapper is registered under given name to allow simple look up by name instead of referencing its class name - especially important when using EJB remote flavor of services where we want to reduce number of dependencies and thus not relying on implementation on client side. So to be able to reference QueryResultMapper by name, NamedQueryMapper should be used which is part of jbpm-services-api. That acts as delegate (lazy delegate) as it will look up the actual mapper when the query is actually performed.

queryService.query("my query def", new NamedQueryMapper<Collection<ProcessInstanceDesc>>("ProcessInstances"), new QueryContext());

QueryParamBuilder

QueryParamBuilder that provides more advanced way of building filters for our data sets. By default when using query method of QueryService that accepts zero or more QueryParam instances (as we have seen in above examples) all of these params will be joined with AND operator meaning all of them must match. But that’s not always the case so that’s why QueryParamBuilder has been introduced for users to build their on builders which will provide filters at the time the query is issued.

There is one QueryParamBuilder available out of the box and it is used to cover default QueryParams that are based on so called core functions. These core functions are SQL based conditions and includes following

  • IS_NULL

  • NOT_NULL

  • EQUALS_TO

  • NOT_EQUALS_TO

  • LIKE_TO

  • GREATER_THAN

  • GREATER_OR_EQUALS_TO

  • LOWER_THAN

  • LOWER_OR_EQUALS_TO

  • BETWEEN

  • IN

  • NOT_IN

QueryParamBuilder is simple interface that is invoked as long as its build method returns non null value before query is performed. So you can build up a complex filter options that could not be simply expressed by list of QueryParams. Here is basic implementation of QueryParamBuilder to give you a jump start to implement your own - note that it relies on DashBuilder Dataset API.

public class TestQueryParamBuilder implements QueryParamBuilder<ColumnFilter> {

    private Map<String, Object> parameters;
    private boolean built = false;
    public TestQueryParamBuilder(Map<String, Object> parameters) {
        this.parameters = parameters;
    }

    @Override
    public ColumnFilter build() {
        // return null if it was already invoked
        if (built) {
            return null;
        }

        String columnName = "processInstanceId";

        ColumnFilter filter = FilterFactory.OR(
                FilterFactory.greaterOrEqualsTo((Long)parameters.get("min")),
                FilterFactory.lowerOrEqualsTo((Long)parameters.get("max")));
        filter.setColumnId(columnName);

        built = true;
        return filter;
    }

}

Once you have query param builder implemented you simply use its instance when performing query via QueryService

queryService.query("my query def", ProcessInstanceQueryMapper.get(), new QueryContext(), paramBuilder);

Typical usage scenario

First thing user needs to do is to define data set - view of the data you want to work with - so called QueryDefinition in services api.

SqlQueryDefinition query = new SqlQueryDefinition("getAllProcessInstances", "java:jboss/datasources/ExampleDS");
query.setExpression("select * from processinstancelog");

This is the simplest possible query definition as it can be:

  • constructor takes

    • a unique name that identifies it on runtime

    • data source JNDI name used when performing queries on this definition - in other words source of data

  • expression - the most important part - is the sql statement that builds up the view to be filtered when performing queries

Once we have the sql query definition we can register it so it can be used later for actual queries.

queryService.registerQuery(query);

From now on, this query definition can be used to perform actual queries (or data look ups to use terminology from data sets). Following is the basic one that collects data as is, without any filtering

Collection<ProcessInstanceDesc> instances = queryService.query("getAllProcessInstances", ProcessInstanceQueryMapper.get(), new QueryContext());

Above query was very simple and used defaults from QueryContext - paging and sorting. So let’s take a look at one that changes the defaults of the paging and sorting

QueryContext ctx = new QueryContext(0, 100, "start_date", true);
         
Collection<ProcessInstanceDesc> instances = queryService.query("getAllProcessInstances", ProcessInstanceQueryMapper.get(), ctx);

Now let’s take a look at how to do data filtering

// single filter param
Collection<ProcessInstanceDesc> instances = queryService.query("getAllProcessInstances", ProcessInstanceQueryMapper.get(), new QueryContext(), QueryParam.likeTo(COLUMN_PROCESSID, true, "org.jbpm%"));
 
// multiple filter params (AND)
Collection<ProcessInstanceDesc> instances = queryService.query("getAllProcessInstances", ProcessInstanceQueryMapper.get(), new QueryContext(),
 QueryParam.likeTo(COLUMN_PROCESSID, true, "org.jbpm%"),
 QueryParam.in(COLUMN_STATUS, 1, 3));

With that end user is put in driver seat to define what data and how they should be fetched. Not being limited by JPA provider nor anything else. Moreover this promotes use of tailored queries for your environment as in most of the case there will be single data base used and thus specific features of that data base can be used to increase performance.

Further examples can be found here.

6.5.7. ProcessInstanceMigrationService

ProcessInstanceMigrationService provides administrative utility to move given process instance(s) from one deployment to another or one process definition to another. It’s main responsibility is to allow basic upgrade of process definition behind given process instance. That might include mapping of currently active nodes to other nodes in new definition.

Migration does not deal with process or task variables, they are not affected by migration. Essentially process instance migration means a change of underlying process definition process engine uses to move on with process instance.

Even though process instance migration is available it’s recommended to let active process instances finish and then start new instances with new version whenever possible. In case that approach can’t be used, migration of active process instance needs to be carefully planned before its execution as it might lead to unexpected issues.Most important to take into account is:

  • is new process definition backward compatible?

  • are there any data changes (variables that could affect process instance decisions after migration)?

  • is there need for node mapping?

Answers to these question might save a lot of headache and production problems after migration. Best is to always stick with backward compatible processes - like extending process definition rather than removing nodes. Though that’s not always possible and in some cases there is a need to remove certain nodes from process definition. In that situation, migration needs to be instructed how to map nodes that were removed in new definition in case active process instance is at the moment in such a node.

Node mapping is given as a map of node ids (UniqueIds that are set in the definition) where key is the source node id (from process definition used by process instance) to target node id (in new process definition).

Node mapping can only be used to map same type of nodes e.g. user task to user task.

Again, process or task variables are not affected by process instance migration at the moment.

ProcessInstanceMigrationService comes with several flavors of migrate operation:

ProcessInstanceMigrationService
----
public interface ProcessInstanceMigrationService {
 /**
 * Migrates given process instance that belongs to source deployment, into target process id that belongs to target deployment.
 * Following rules are enforced:
 * <ul>
 * <li>source deployment id must be there</li>
 * <li>process instance id must point to existing and active process instance</li>
 * <li>target deployment must exist</li>
 * <li>target process id must exist in target deployment</li>
 * </ul>
 * Migration returns migration report regardless of migration being successful or not that needs to be examined for migration outcome.
 * @param sourceDeploymentId deployment that process instance to be migrated belongs to
 * @param processInstanceId id of the process instance to be migrated
 * @param targetDeploymentId id of deployment that target process belongs to
 * @param targetProcessId id of the process process instance should be migrated to
 * @return returns complete migration report
 */
 MigrationReport migrate(String sourceDeploymentId, Long processInstanceId, String targetDeploymentId, String targetProcessId);
 /**
 * Migrates given process instance (with node mapping) that belongs to source deployment, into target process id that belongs to target deployment.
 * Following rules are enforced:
 * <ul>
 * <li>source deployment id must be there</li>
 * <li>process instance id must point to existing and active process instance</li>
 * <li>target deployment must exist</li>
 * <li>target process id must exist in target deployment</li>
 * </ul>
 * Migration returns migration report regardless of migration being successful or not that needs to be examined for migration outcome.
 * @param sourceDeploymentId deployment that process instance to be migrated belongs to
 * @param processInstanceId id of the process instance to be migrated
 * @param targetDeploymentId id of deployment that target process belongs to
 * @param targetProcessId id of the process process instance should be migrated to
 * @param nodeMapping node mapping - source and target unique ids of nodes to be mapped - from process instance active nodes to new process nodes
 * @return returns complete migration report
 */
 MigrationReport migrate(String sourceDeploymentId, Long processInstanceId, String targetDeploymentId, String targetProcessId, Map<String, String> nodeMapping);
 /**
 * Migrates given process instances that belong to source deployment, into target process id that belongs to target deployment.
 * Following rules are enforced:
 * <ul>
 * <li>source deployment id must be there</li>
 * <li>process instance id must point to existing and active process instance</li>
 * <li>target deployment must exist</li>
 * <li>target process id must exist in target deployment</li>
 * </ul>
 * Migration returns list of migration report - one per process instance, regardless of migration being successful or not that needs to be examined for migration outcome.
 * @param sourceDeploymentId deployment that process instance to be migrated belongs to
 * @param processInstanceIds list of process instance id to be migrated
 * @param targetDeploymentId id of deployment that target process belongs to
 * @param targetProcessId id of the process process instance should be migrated to
 * @return returns complete migration report
 */
 List<MigrationReport> migrate(String sourceDeploymentId, List<Long> processInstanceIds, String targetDeploymentId, String targetProcessId);
 /**
 * Migrates given process instances (with node mapping) that belong to source deployment, into target process id that belongs to target deployment.
 * Following rules are enforced:
 * <ul>
 * <li>source deployment id must be there</li>
 * <li>process instance id must point to existing and active process instance</li>
 * <li>target deployment must exist</li>
 * <li>target process id must exist in target deployment</li>
 * </ul>
 * Migration returns list of migration report - one per process instance, regardless of migration being successful or not that needs to be examined for migration outcome.
 * @param sourceDeploymentId deployment that process instance to be migrated belongs to
 * @param processInstanceIds list of process instance id to be migrated
 * @param targetDeploymentId id of deployment that target process belongs to
 * @param targetProcessId id of the process process instance should be migrated to
 * @param nodeMapping node mapping - source and target unique ids of nodes to be mapped - from process instance active nodes to new process nodes
 * @return returns list of migration reports one per each process instance
 */
 List<MigrationReport> migrate(String sourceDeploymentId, List<Long> processInstanceIds, String targetDeploymentId, String targetProcessId, Map<String, String> nodeMapping);
}
----

Migration can either be performed for single process instance or multiple process instances at the same time. Multiple process instances migration is a utility method on top of single instance, instead of calling it multiple times, users call it once and then service will take care of the migration of individual process instances.

Multi instance migration does migrate each instance in separation (transaction) to secure that one won’t affect the other and then produces dedicated migration reports for each process instance
6.5.7.1. Migration report

Migration is always comcluded with migration report that is per each process instance. That migration report provides following information:

  • start and end date of the migration

  • outcome of the migration - success or failure

  • complete log entry - all steps performed during migration, entry can be INFO, WARN or ERROR - in case of ERROR there will be at most one as they are causing migration to be immedietely terminated.

6.5.7.2. Example

Following is an example of how to invoke the migration

 protected static final String MIGRATION_ARTIFACT_ID = "test-migration";
 protected static final String MIGRATION_GROUP_ID = "org.jbpm.test";
 protected static final String MIGRATION_VERSION_V1 = "1.0.0";
 protected static final String MIGRATION_VERSION_V2 = "2.0.0";
 // first deploy both versions
 deploymentUnitV1 = new KModuleDeploymentUnit(MIGRATION_GROUP_ID, MIGRATION_ARTIFACT_ID, MIGRATION_VERSION_V1);
 deploymentService.deploy(deploymentUnitV1);
 // ... version 2
 deploymentUnitV2 = new KModuleDeploymentUnit(MIGRATION_GROUP_ID, MIGRATION_ARTIFACT_ID, MIGRATION_VERSION_V2);
 deploymentService.deploy(deploymentUnitV2);
 // next start process instance in version 1
 long processInstanceId = processService.startProcess(deploymentUnitV1.getIdentifier(), "processID-V1");
// and once the instance is active it can be migrated
MigrationReport report = migrationService.migrate(deploymentUnitV1.getIdentifier(), processInstanceId, deploymentUnitV2.getIdentifier(), "processID-V2");
// as last step check if the migration finished successfully
report.isSuccessful()
6.5.7.3. Known limitations
  • When a new or modified task requires inputs which are not available in the migrated v2 process instance.

  • Modifying the tasks prior to the active task where the changes have an impact on the further processing.

  • Removing a human task which is currently active (can only be replaced - requires to be mapped to another human task)

  • Adding a new task parallel to the single active task (all branches in AND gateway are not activated - process will stuck)

  • Changing or removing the active recurring timer events (won’t be changed in DB)

  • Fixing or updating inputs and outputs in an active task (task data aren’t migrated)

  • Node mapping updates only the task node name and description! (other task fields won’t be mapped including the TaskName variable)

6.5.8. Working with deployments

Deployment Service provides convinient way to put business assets to an execution environment but there are cases that requires some additional management to make them available in right context.

Activation and Deactivation of deployments

Imagine situation where there are number of processes already running of given deployment and then new version of these processes comes into the runtime environment. With that administrator can decide that new instances of given process definition should be using new version only while already active instances should continue with the previous version.

To help with that deployment service has been equipped with following methods:

  • activate

    allows to activate given deployment so it can be available for interaction meaning will show its process definition and allow to start new process instances of that project’s processes

  • deactivate

    allows to deactivate deployment which will disable option to see or start new process instances of that project’s processes but will allow to continue working with already active process instances, e.g. signal, work with user task etc

This feature allows smooth transition between project versions whitout need of process instance migration.

Deployment synchronization

Prior to jBPM 6.2, jbpm services did not have deployment store by default. When embedded in jbpm-console/kie-wb they utilized sistem.git VFS repository to preserve deployed units across server restarts. While that works fine, it comes with some drawbacks:

  • not available for custom systems that use services

  • requires complex setup in cluster - zookeeper and helix

With version 6.2 jbpm services come with deployment synchronizer that stores available deployments into data base, including its deployment descriptor. At the same time it constantly monitors that table to keep it in sync with other installations that might be using same data source. This is especially important when running in cluster or when jbpm console runs next to custom application and both should be able to operate on the same artifacts.

By default synchronization must be configured (when runing as core services while it is automatically enabled for ejb and cdi extensions). To configure synchronization following needs to be configured:

TransactionalCommandService commandService = new TransactionalCommandService(emf);

DeploymentStore store = new DeploymentStore();
store.setCommandService(commandService);

DeploymentSynchronizer sync = new DeploymentSynchronizer();
sync.setDeploymentService(deploymentService);
sync.setDeploymentStore(store);

DeploymentSyncInvoker invoker = new DeploymentSyncInvoker(sync, 2L, 3L, TimeUnit.SECONDS);
invoker.start();
....
invoker.stop();

With this, deployments will be synchronized every 3 seconds with initial delay of two seconds.

Invoking latest version of project’s processes

In case there is a need to always work with latest version of project’s process, services allow to interact with various operations using deployment id with latest keyword. Let’s go over an example to better understand the feature.

Initially deployed unit is org.jbpm:HR:1.0 which has the first version of an hiring process. After several weeks, new version is developed and deployed to the execution server - org.jbpm:HR.2.0 with version 2 of the hiring process.

To allow callers of the services to interact without being worried if they work with latest version, they can use following deployment id:

org.jbpm.HR:latest

this will alwyas find out latest available version of project that is identified by:

  • groupId: org.jbpm

  • artifactId: HR

version comparizon is based on Maven version numbers and relies on Maen based algorithm to find the latest one.

This is only supported when process identifier remains the same in all project versions

Here is a complete example with deployment of multiple versions and interacting always with the latest:

KModuleDeploymentUnit deploymentUnitV1 = new KModuleDeploymentUnit("org.jbpm", "HR", "1.0");
deploymentService.deploy(deploymentUnitV1);

long processInstanceId = processService.startProcess("org.jbpm:HR:LATEST", "customtask");
ProcessInstanceDesc piDesc = runtimeDataService.getProcessInstanceById(processInstanceId);

// we have started process with project's version 1
assertEquals(deploymentUnitV1.getIdentifier(), piDesc.getDeploymentId());

// next we deploy version 1
KModuleDeploymentUnit deploymentUnitV2 = new KModuleDeploymentUnit("org.jbpm", "HR", "2.0");
deploymentService.deploy(deploymentUnitV2);

processInstanceId = processService.startProcess("org.jbpm:HR:LATEST", "customtask");
piDesc = runtimeDataService.getProcessInstanceById(processInstanceId);

// this time we have started process with project's version 2
assertEquals(deploymentUnitV2.getIdentifier(), piDesc.getDeploymentId());

As illustrated this provides very powerful feature when interacting with frequently chaning environment that allows to always be up to date when it comes to use of process definitions.

This feature is also available in REST interface so whenever sending request with deployment id, it’s enough to replace concrete version with LATEST keyword to make use of this feature.

6.6. Configuration

There are several control parameters available to alter engine default behavior. This allows to fine tune the execution for the environment needs and actual requirements. All of these parameters are set as JVM system properties, usually with -D when starting program e.g. application server.

Table 5. Control parameters
Name Possible values Default value Description

jbpm.ut.jndi.lookup

String

Alternative JNDI name to be used when there is no access to the default one (java:comp/UserTransaction)

jbpm.enable.multi.con

true|false

false

Enables multiple incoming/outgoing sequence flows support for activities

jbpm.business.calendar.properties

String

/jbpm.business.calendar.properties

Allows to provide alternative classpath location of business calendar configuration file

jbpm.overdue.timer.delay

Long

2000

Specifies delay for overdue timers to allow proper initialization, in milliseconds

jbpm.process.name.comparator

String

Allows to provide alternative comparator class to empower start process by name feature, if not set NumberVersionComparator is used

jbpm.loop.level.disabled

true|false

true

Allows to enable or disable loop iteration tracking, to allow advanced loop support when using XOR gateways

org.kie.mail.session

String

mail/jbpmMailSession

Allows to provide alternative JNDI name for mail session used by Task Deadlines

jbpm.usergroup.callback.properties

String

/jbpm.usergroup.callback.properties

Allows to provide alternative classpath location for user group callback implementation (LDAP, DB)

jbpm.user.group.mapping

String

${jboss.server.config.dir}/roles.properties

Allows to provide alternative location of roles.properties for JBossUserGroupCallbackImpl

jbpm.user.info.properties

String

/jbpm.user.info.properties

Allows to provide alternative classpath location of user info configuration (used by LDAPUserInfoImpl)

org.jbpm.ht.user.separator

String

,

Allows to provide alternative separator of actors and groups for user tasks, default is comma (,)

org.quartz.properties

String

Allows to provide location of the quartz config file to activate quartz based timer service

jbpm.data.dir

String

${jboss.server.data.dir} is available otherwise ${java.io.tmpdir}

Allows to provide location where data files produced by jbpm should be stored

org.kie.executor.pool.size

Integer

1

Allows to provide thread pool size for jbpm executor

org.kie.executor.retry.count

Integer

3

Allows to provide number of retries attempted in case of error by jbpm executor

org.kie.executor.interval

Integer

3

Allows to provide frequency used to check for pending jobs by jbpm executor, in seconds

org.kie.executor.disabled

true|false

true

Enables or disable jbpm executor

org.kie.store.services.class

String

org.drools.persistence.jpa.KnowledgeStoreServiceImpl

Fully qualified name of the class that implements KieStoreServices that will be responsible for bootstraping KieSession instances

7. Processes

7.1. What is BPMN 2.0

"The primary goal of BPMN is to provide a notation that is readily understandable by all business users, from the business analysts that create the initial drafts of the processes, to the technical developers responsible for implementing the technology that will perform those processes, and finally, to the business people who will manage and monitor those processes."

The Business Process Model and Notation (BPMN) 2.0 specification is an OMG specification that not only defines a standard on how to graphically represent a business process (like BPMN 1.x), but now also includes execution semantics for the elements defined, and an XML format on how to store (and share) process definitions.

jBPM6 allows you to execute processes defined using the BPMN 2.0 XML format. That means that you can use all the different jBPM6 tooling to model, execute, manage and monitor your business processes using the BPMN 2.0 format for specifying your executable business processes. Actually, the full BPMN 2.0 specification also includes details on how to represent things like choreographies and collaboration. The jBPM project however focuses on that part of the specification that can be used to specify executable processes.

Executable processes in BPMN consist of a different types of nodes being connected to each other using sequence flows. The BPMN 2.0 specification defines three main types of nodes:

  • Events: They are used to model the occurrence of a particular event. This could be a start event (that is used to indicate the start of the process), end events (that define the end of the process, or of that subflow) and intermediate events (that indicate events that might occur during the execution of the process).

  • Activities: These define the different actions that need to be performed during the execution of the process. Different types of tasks exist, depending on the type of activity you are trying to model (e.g. human task, service task, etc.) and activities could also be nested (using different types of sub-processes).

  • Gateways: Can be used to define multiple paths in the process. Depending on the type of gateway, these might indicate parallel execution, choice, etc.

jBPM6 does not implement all elements and attributes as defined in the BPMN 2.0 specification. We do however support a significant subset, including the most common node types that can be used inside executable processes. This includes (almost) all elements and attributes as defined in the "Common Executable" subclass of the BPMN 2.0 specification, extended with some additional elements and attributes we believe are valuable in that context as well. The full set of elements and attributes that are supported can be found below, but it includes elements like:

  • Flow objects

    • Events

      • Start Event (None, Conditional, Signal, Message, Timer)

      • End Event (None, Terminate, Error, Escalation, Signal, Message, Compensation)

      • Intermediate Catch Event (Signal, Timer, Conditional, Message)

      • Intermediate Throw Event (None, Signal, Escalation, Message, Compensation)

      • Non-interrupting Boundary Event (Escalation, Signal, Timer, Conditional, Message)

      • Interrupting Boundary Event (Escalation, Error, Signal, Timer, Conditional, Message, Compensation)

    • Activities

      • Script Task

      • Task

      • Service Task

      • User Task

      • Business Rule Task

      • Manual Task

      • Send Task

      • Receive Task

      • Reusable Sub-Process (Call Activity)

      • Embedded Sub-Process

      • Event Sub-Process

      • Ad-Hoc Sub-Process

      • Data-Object

    • Gateways

      • Diverging

        • Exclusive

        • Inclusive

        • Parallel

        • Event-Based

      • Converging

        • Exclusive

        • Inclusive

        • Parallel

    • Lanes

  • Data

    • Java type language

    • Process properties

    • Embedded Sub-Process properties

    • Activity properties

  • Connecting objects

    • Sequence flow

For example, consider the following "Hello World" BPMN 2.0 process, which does nothing more that writing out a "Hello World" statement when the process is started.

HelloWorld

An executable version of this process expressed using BPMN 2.0 XML would look something like this:

<?xml version="1.0" encoding="UTF-8"?>
<definitions id="Definition"
             targetNamespace="http://www.example.org/MinimalExample"
             typeLanguage="http://www.java.com/javaTypes"
             expressionLanguage="http://www.mvel.org/2.0"
             xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
             xmlns:xs="http://www.w3.org/2001/XMLSchema-instance"
             xs:schemaLocation="http://www.omg.org/spec/BPMN/20100524/MODEL BPMN20.xsd"
             xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI"
             xmlns:dc="http://www.omg.org/spec/DD/20100524/DC"
             xmlns:di="http://www.omg.org/spec/DD/20100524/DI"
             xmlns:tns="http://www.jboss.org/drools">

  <process processType="Private" isExecutable="true" id="com.sample.HelloWorld" name="Hello World" >

    <!-- nodes -->
    <startEvent id="_1" name="StartProcess" />
    <scriptTask id="_2" name="Hello" >
      <script>System.out.println("Hello World");</script>
    </scriptTask>
    <endEvent id="_3" name="EndProcess" >
        <terminateEventDefinition/>
    </endEvent>

    <!-- connections -->
    <sequenceFlow id="_1-_2" sourceRef="_1" targetRef="_2" />
    <sequenceFlow id="_2-_3" sourceRef="_2" targetRef="_3" />

  </process>

  <bpmndi:BPMNDiagram>
    <bpmndi:BPMNPlane bpmnElement="Minimal" >
      <bpmndi:BPMNShape bpmnElement="_1" >
        <dc:Bounds x="15" y="91" width="48" height="48" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape bpmnElement="_2" >
        <dc:Bounds x="95" y="88" width="83" height="48" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape bpmnElement="_3" >
        <dc:Bounds x="258" y="86" width="48" height="48" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNEdge bpmnElement="_1-_2" >
        <di:waypoint x="39" y="115" />
        <di:waypoint x="75" y="46" />
        <di:waypoint x="136" y="112" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge bpmnElement="_2-_3" >
        <di:waypoint x="136" y="112" />
        <di:waypoint x="240" y="240" />
        <di:waypoint x="282" y="110" />
      </bpmndi:BPMNEdge>
    </bpmndi:BPMNPlane>
  </bpmndi:BPMNDiagram>

</definitions>

To create your own process using BPMN 2.0 format, you can

  • The jBPM Designer is an open-source web-based editor that supports the BPMN 2.0 format. We have embedded it into jbpm console for BPMN 2.0 process visualization and editing. You could use the Designer (either standalone or integrated) to create / edit BPMN 2.0 processes and then export them to BPMN 2.0 format or save them into repository and import them so they can be executed.

  • A new BPMN2 Eclipse plugin is being created to support the full BPMN2 specification.

  • You can always manually create your BPMN 2.0 process files by writing the XML directly. You can validate the syntax of your processes against the BPMN 2.0 XSD, or use the validator in the Eclipse plugin to check both syntax and completeness of your model.

  • Drools Eclipse Process editor has been deprecated in favor of BPMN2 Modeler for process modeling. It can still be used for limited number of supported elements but should be faced out as it is not being developed any more.

    Create a new Process file using the Drools Eclipse plugin wizard and in the last page of the wizard, make sure you select Drools 5.1 code compatibility. This will create a new process using the BPMN 2.0 XML format. Note however that this is not exactly a BPMN 2.0 editor, as it still uses different attributes names etc. It does however save the process using valid BPMN 2.0 syntax. Also note that the editor does not support all node types and attributes that are already supported in the execution engine.

The following code fragment shows you how to load a BPMN2 process into your knowledge base …​

private static KnowledgeBase createKnowledgeBase() throws Exception {
    KieHelper kieHelper = new KieHelper();
    KieBase kieBase = kieHelper
    .addResource(ResourceFactory.newClassPathResource("sample.bpmn2"))
    .build();

    return kieBase;
}

... and how to execute this process …​

KieBase kbase = createKnowledgeBase();
KieSession ksession = kbase.newKieSession();
ksession.startProcess("com.sample.HelloWorld");

For more detail, check out the chapter on the API and the basics.

7.2. Process

Process

A business process is a graph that describes the order in which a series of steps need to be executed, using a flow chart. A process consists of a collection of nodes that are linked to each other using connections. Each of the nodes represents one step in the overall process while the connections specify how to transition from one node to the other. A large selection of predefined node types have been defined. This chapter describes how to define such processes and use them in your application.

7.2.1. Creating a process

Processes can be created by using one of the following three methods:

  1. Using the graphical process editor such as jBPM web designer or Eclipse BPMN2 modeler

  2. As an XML file, according to the XML process format as defined in the XML Schema Definition in the BPMN 2.0 specification.

  3. By directly creating a process using the Process API.

7.2.1.1. Using the graphical BPMN2 Editor

The graphical BPMN2 editor is an editor that allows you to create a process by dragging and dropping different nodes on a canvas and editing the properties of these nodes. The graphical BPMN2 modeler is an Eclipse plugin hosted on eclipse.org that provides number of contributors where one of them is jBPM project. Once you have set up a jBPM project (see the installer for creating a working Eclipse environment where you can start), you can start adding processes. When in a project, launch the "New" wizard (use Ctrl+N) or right-click the directory you would like to put your process in and select "New", then "File". Give the file a name and the extension bpmn (e.g. MyProcess.bpmn). This will open up the process editor (you can safely ignore the warning that the file could not be read, this is just because the file is still empty).

First, ensure that you can see the Properties View down the bottom of the Eclipse window, as it will be necessary to fill in the different properties of the elements in your process. If you cannot see the properties view, open it using the menu "Window", then "Show View" and "Other…​", and under the "General" folder select the Properties View.

NewProcess
Figure 8. New process

The process editor consists of a palette, a canvas and an outline view. To add new elements to the canvas, select the element you would like to create in the palette and then add them to the canvas by clicking on the preferred location. For example, click on the "End Event" icon in the palette of the GUI. Clicking on an element in your process allows you to set the properties of that element. You can connect the nodes (as long as it is permitted by the different types of nodes) by using "Sequence Flow" from the palette.

You can keep adding nodes and connections to your process until it represents the business logic that you want to specify.

7.2.1.2. Defining processes using XML

It is also possible to specify processes using the underlying BPMN 2.0 XML directly. The syntax of these XML processes is defined using the BPMN 2.0 XML Schema Definition. For example, the following XML fragment shows a simple process that contains a sequence of a Start Event, a Script Task that prints "Hello World" to the console, and an End Event.

<?xml version="1.0" encoding="UTF-8"?>
<definitions id="Definition"
             targetNamespace="http://www.jboss.org/drools"
             typeLanguage="http://www.java.com/javaTypes"
             expressionLanguage="http://www.mvel.org/2.0"
             xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"Rule Task
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://www.omg.org/spec/BPMN/20100524/MODEL BPMN20.xsd"
             xmlns:g="http://www.jboss.org/drools/flow/gpd"
             xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI"
             xmlns:dc="http://www.omg.org/spec/DD/20100524/DC"
             xmlns:di="http://www.omg.org/spec/DD/20100524/DI"
             xmlns:tns="http://www.jboss.org/drools">

  <process processType="Private" isExecutable="true" id="com.sample.hello" name="Hello Process" >

    <!-- nodes -->
    <startEvent id="_1" name="Start" />
    <scriptTask id="_2" name="Hello" >
      <script>System.out.println("Hello World");</script>
    </scriptTask>
    <endEvent id="_3" name="End" >
        <terminateEventDefinition/>
    </endEvent>

    <!-- connections -->
    <sequenceFlow id="_1-_2" sourceRef="_1" targetRef="_2" />
    <sequenceFlow id="_2-_3" sourceRef="_2" targetRef="_3" />

  </process>

  <bpmndi:BPMNDiagram>
    <bpmndi:BPMNPlane bpmnElement="com.sample.hello" >
      <bpmndi:BPMNShape bpmnElement="_1" >
        <dc:Bounds x="16" y="16" width="48" height="48" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape bpmnElement="_2" >
        <dc:Bounds x="96" y="16" width="80" height="48" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNShape bpmnElement="_3" >
        <dc:Bounds x="208" y="16" width="48" height="48" />
      </bpmndi:BPMNShape>
      <bpmndi:BPMNEdge bpmnElement="_1-_2" >
        <di:waypoint x="40" y="40" />
        <di:waypoint x="136" y="40" />
      </bpmndi:BPMNEdge>
      <bpmndi:BPMNEdge bpmnElement="_2-_3" >
        <di:waypoint x="136" y="40" />
        <di:waypoint x="232" y="40" />
      </bpmndi:BPMNEdge>
    </bpmndi:BPMNPlane>
  </bpmndi:BPMNDiagram>

</definitions>

The process XML file consists of two parts, the top part (the "process" element) contains the definition of the different nodes and their properties, the lower part (the "BPMNDiagram" element) contains all graphical information, like the location of the nodes. The process XML consist of exactly one <process> element. This element contains parameters related to the process (its type, name, id and package name), and consists of three subsections: a header section (where process-level information like variables, globals, imports and lanes can be defined), a nodes section that defines each of the nodes in the process, and a connections section that contains the connections between all the nodes in the process. In the nodes section, there is a specific element for each node, defining the various parameters and, possibly, sub-elements for that node type.

Table 6. jBPM BPMN2 constructs
.The different types of BPMN2 events image::BPMN2/Events.png[] .The different types of BPMN2 activities and gateways image::BPMN2/ActivitiesGateways.png[]
7.2.1.3. Details: Process properties

A BPMN2 process is a flow chart where different types of nodes are linked using connections. The process itself exposes the following properties:

  • Id: The unique id of the process.

  • Name: The display name of the process.

  • Version: The version number of the process.

  • Package: The package (namespace) the process is defined in.

ProcessProperties
Figure 9. BPMN2 process properties

In addition to that following can be defined as well:

  • Variables: Variables can be defined to store data during the execution of your process. See section “[_sec.data]” for details.

  • Swimlanes: Specify the swimlanes used in this process for assigning human tasks. See chapter “[_ch.human_tasks]” for details.

ProcessVariables
Figure 10. BPMN2 process variables

7.3. Activities

7.3.1. Script task

ScriptTask
Figure 11. Script task

Represents a script that should be executed in this process. A Script Task should have one incoming connection and one outgoing connection. The associated action specifies what should be executed, the dialect used for coding the action (i.e., Java, JavaScript or MVEL), and the actual action code. This code can access any variables and globals. There is also a predefined variable kcontext that references the ProcessContext object (which can, for example, be used to access the current ProcessInstance or NodeInstance, and to get and set variables, or get access to the ksession using kcontext.getKieRuntime()). When a Script Task is reached in the process, it will execute the action and then continue with the next node. It contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • Action: The action script associated with this action node.

Note that you can write any valid Java code inside a script node. This basically allows you to do anything inside such a script node. There are some caveats however:

  • When trying to create a higher-level business process, that should also be understood by business users, it is probably wise to avoid low-level implementation details inside the process, including inside these script tasks. A Script Task could still be used to quickly manipulate variables etc. but other concepts like a Service Task could be used to model more complex behaviour in a higher-level manner.

  • Scripts should be immediate. They are using the engine thread to execute the script. Scripts that could take some time to execute should probably be modeled as an asynchronous Service Task.

  • You should try to avoid contacting external services through a script node. Not only does this usually violate the first two caveats, it is also interacting with external services without the knowledge of the engine, which can be problematic, especially when using persistence and transactions. In general, it is probably wiser to model communication with an external service using a service task.

  • Scripts should not throw exceptions. Runtime exceptions should be caught and for example managed inside the script or transformed into signals or errors that can then be handled inside the process.

7.3.2. Service task

ServiceTask
Figure 12. Service task

Represents an (abstract) unit of work that should be executed in this process. All work that is executed outside the process engine should be represented (in a declarative way) using a Service Task. Different types of services are predefined, e.g., sending an email, logging a message, etc. Users can define domain-specific services or work items, using a unique name and by defining the parameters (input) and results (output) that are associated with this type of work. Check the chapter on domain-specific processes for a detailed explanation and illustrative examples of how to define and use work items in your processes. When a Service Task is reached in the process, the associated work is executed. A Service Task should have one incoming connection and one outgoing connection.

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • Parameter mapping: Allows copying the value of process variables to parameters of the work item. Upon creation of the work item, the values will be copied.

  • Result mapping: Allows copying the value of result parameters of the work item to a process variable. Each type of work can define result parameters that will (potentially) be returned after the work item has been completed. A result mapping can be used to copy the value of the given result parameter to the given variable in this process. For example, the "FileFinder" work item returns a list of files that match the given search criteria within the result parameter Files. This list of files can then be bound to a process variable for use within the process. Upon completion of the work item, the values will be copied.

  • On-entry and on-exit actions: Actions that are executed upon entry or exit of this node, respectively.

  • Additional parameters: Each type of work item can define additional parameters that are relevant for that type of work. For example, the "Email" work item defines additional parameters such as From, To, Subject and Body. The user can either provide values for these parameters directly, or define a parameter mapping that will copy the value of the given variable in this process to the given parameter; if both are specified, the mapping will have precedence. Parameters of type String can use #{expression} to embed a value in the string. The value will be retrieved when creating the work item, and the substitution expression will be replaced by the result of calling toString() on the variable. The expression could simply be the name of a variable (in which case it resolves to the value of the variable), but more advanced MVEL expressions are possible as well, e.g., \#{person.name.firstname}.

7.3.3. User task

UserTask
Figure 13. User task

Processes can also involve tasks that need to be executed by human actors. A User Task represents an atomic task to be executed by a human actor. It should have one incoming connection and one outgoing connection. User Tasks can be used in combination with Swimlanes to assign multiple human tasks to similar actors. Refer to the chapter on human tasks for more details. A User Task is actually nothing more than a specific type of service node (of type "Human Task"). A User Task contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • TaskName: The name of the human task.

  • Priority: An integer indicating the priority of the human task.

  • Comment: A comment associated with the human task.

  • ActorId: The actor id that is responsible for executing the human task. A list of actor id’s can be specified using a comma (',') as separator.

  • GroupId: The group id that is responsible for executing the human task. A list of group id’s can be specified using a comma (',') as separator.

  • Skippable: Specifies whether the human task can be skipped, i.e., whether the actor may decide not to execute the task.

  • Content: The data associated with this task.

  • Swimlane: The swimlane this human task node is part of. Swimlanes make it easy to assign multiple human tasks to the same actor. See the human tasks chapter for more detail on how to use swimlanes.

  • On entry and on exit actions: Action scripts that are executed upon entry and exit of this node, respectively.

  • Parameter mapping: Allows copying the value of process variables to parameters of the human task. Upon creation of the human tasks, the values will be copied.

  • Result mapping: Allows copying the value of result parameters of the human task to a process variable. Upon completion of the human task, the values will be copied. A human task has a result variable "Result" that contains the data returned by the human actor. The variable "ActorId" contains the id of the actor that actually executed the task.

A user task should define the type of task that needs to be executed (using properties like TaskName, Comment, etc.) and who needs to perform it (using either actorId or groupId). Note that if there is data related to this specific process instance that the end user needs when performing the task, this data should be passed as the content of the task. The task for example does not have access to process variables. Check out the chapter on human tasks to get more detail on how to pass data between human tasks and the process instance.

7.3.4. Reusable sub-process

ReusableSubProcess
Figure 14. Reusable sub-process - Call activity

Represents the invocation of another process from within this process. A sub-process node should have one incoming connection and one outgoing connection. When a Reusable Sub-Process node is reached in the process, the engine will start the process with the given id. It contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • ProcessId: The id of the process that should be executed.

  • Wait for completion (by default true): If this property is true, this sub-process node will only continue if the child process that was started has terminated its execution (completed or aborted); otherwise it will continue immediately after starting the subprocess (so it will not wait for its completion).

  • Independent (by default true): If this property is true, the child process is started as an independent process, which means that the child process will not be terminated if this parent process is completed (or this sub-process node is canceled for some other reason); otherwise the active sub-process will be canceled on termination of the parent process (or cancellation of the sub-process node). Note that you can only set independent to "false" only when "Wait for completion" is set to true.

  • On-entry and on-exit actions: Actions that are executed upon entry or exit of this node, respectively.

  • Parameter in/out mapping: A sub-process node can also define in- and out-mappings for variables. The variables given in the "in" mapping will be used as parameters (with the associated parameter name) when starting the process. The variables of the child process that are defined for the "out" mappings will be copied to the variables of this process when the child process has been completed. Note that you can use "out" mappings only when "Wait for completion" is set to true.

7.3.5. Business rule task

BusinessRuleTask
Figure 15. Business rule task

A Business Rule Task Represents a set of rules that need to be evaluated. The rules are evaluated when the node is reached. A Rule Task should have one incoming connection and one outgoing connection. Rules are defined in separate files using the Drools rule format. Rules can become part of a specific ruleflow group using the ruleflow-group attribute in the header of the rule.

When a Rule Task is reached in the process, the engine will start executing rules that are part of the corresponding ruleflow-group (if any). Execution will automatically continue to the next node if there are no more active rules in this ruleflow group. As a result, during the execution of a ruleflow group, new activations belonging to the currently active ruleflow group can be added to the Agenda due to changes made to the facts by the other rules. Note that the process will immediately continue with the next node if it encounters a ruleflow group where there are no active rules at that time.

If the ruleflow group was already active, the ruleflow group will remain active and execution will only continue if all active rules of the ruleflow group has been completed. It contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • RuleFlowGroup: The name of the ruleflow group that represents the set of rules of this RuleFlowGroup node.

7.3.6. Embedded sub-process

EmbeddedSubProcess
Figure 16. Embedded sub-process

A Sub-Process is a node that can contain other nodes so that it acts as a node container. This allows not only the embedding of a part of the process within such a sub-process node, but also the definition of additional variables that are accessible for all nodes inside this container. A sub-process should have one incoming connection and one outgoing connection. It should also contain one start node that defines where to start (inside the Sub-Process) when you reach the sub-process. It should also contain one or more end events. Note that, if you use a terminating event node inside a sub-process, you are terminating just that sub-process. A sub-process ends when there are no more active nodes inside the sub-process. It contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • Variables: Additional variables can be defined to store data during the execution of this node. See section “[_sec.data]” for details.

7.3.7. Multi-instance sub-process

MultipleInstances
Figure 17. Multi-instance sub-process

A Multiple Instance sub-process is a special kind of sub-process that allows you to execute the contained process segment multiple times, once for each element in a collection. A multiple instance sub-process should have one incoming connection and one outgoing connection. It waits until the embedded process fragment is completed for each of the elements in the given collection before continuing. It contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • CollectionExpression: The name of a variable that represents the collection of elements that should be iterated over. The collection variable should be an array or of type java.util.Collection. If the collection expression evaluates to null or an empty collection, the multiple instances sub-process will be completed immediately and follow its outgoing connection.

  • VariableName: The name of the variable to contain the current element from the collection. This gives nodes within the composite node access to the selected element.

  • CollectionOutput: The name of a variable that represents collection of elements that will gather all output of the multi instance sub process

  • OutputVariableName: The name of the variable to contain the currentl output from the multi instance activitiy

  • CompletionCondition: MVEL expression that will be evaluated on each instance completion to check if given multi instance activity can already be completed. In case it evaluates to true all other remaining instances within multi instance activity will be canceled.

7.4. Events

7.4.1. Start event

StartEvent
Figure 18. Start event

The start of the process. A process should have exactly one start node (none start node which does not have event definitions), which cannot have incoming connections and should have one outgoing connection. Whenever a process is started, execution will start at this node and automatically continue to the first node linked to this start event, and so on. It contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

7.4.2. End events

7.4.2.1. End event
EndEvent
Figure 19. End event

The end of the process. A process should have one or more end events. The End Event should have one incoming connection and cannot have any outgoing connections. It contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • Terminate: An End Event can terminate the entire process or just the path. When a process instance is terminated, it means its state is set to completed and all other nodes that might still be active (on parallel paths) in this process instance are canceled. Non-terminating end events are simply end for this path (execution of this branch will end here), but other parallel paths can still continue. A process instance will automatically complete if there are no more active paths inside that process instance (for example, if a process instance reaches a non-terminating end node but there are no more active branches inside the process instance, the process instance will be completed anyway). Terminating end events are visualized using a full circle inside the event node, non-terminating event nodes are empty. Note that, if you use a terminating event node inside a sub-process, you are terminating just that sub-process and top level continues.

7.4.2.2. Throwing error event
ErrorEndEvent
Figure 20. Throwing error event

An Error Event can be used to signal an exceptional condition in the process. It should have one incoming connection and no outgoing connections. When an Error Event is reached in the process, it will throw an error with the given name. The process will search for an appropriate error handler that is capable of handling this kind of fault. If no error handler is found, the process instance will be aborted. An Error Event contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • FaultName: The name of the fault. This name is used to search for appropriate exception handlers that are capable of handling this kind of fault.

  • FaultVariable: The name of the variable that contains the data associated with this fault. This data is also passed on to the exception handler (if one is found).

Error handlers can be specified using boundary events.

7.4.3. Intermediate events

7.4.3.1. Catching timer event
IntermediateTimerEvent
Figure 21. Catching timer event

Represents a timer that can trigger one or multiple times after a given period of time. A Timer Event should have one incoming connection and one outgoing connection. The timer delay specifies how long the timer should wait before triggering the first time. When a Timer Event is reached in the process, it will start the associated timer. The timer is canceled if the timer node is canceled (e.g., by completing or aborting the enclosing process instance). Consult the section “[_sec.timers]” for more information. The Timer Event contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • Timer delay: The delay that the node should wait before triggering the first time. The expression should be of the form [d][#h][#m][#s][[ms]]. This allows you to specify the number of days, hours, minutes, seconds and milliseconds (which is the default if you don’t specify anything). For example, the expression "1h" will wait one hour before triggering the timer. The expression could also use #{expr} to dynamically derive the delay based on some process variable. Expr in this case could be a process variable, or a more complex expression based on a process variable (e.g. myVariable.getValue()). It does support CRON like expression as well.

  • Timer period: The period between two subsequent triggers. If the period is 0, the timer should only be triggered once. The expression should be of the form [d][#h][#m][#s][[ms]]. You can specify the number of days, hours, minutes, seconds and milliseconds (which is the default if you don’t specify anything). For example, the expression "1h" will wait one hour before triggering the timer again. The expression could also use #{expr} to dynamically derive the period based on some process variable. Expr in this case could be a process variable, or a more complex expression based on a process variable (e.g. myVariable.getValue()).

Timer events could also be specified as boundary events on sub-processes and tasks that are not automatic tasks like script task that have no wait state as timer will not have a change to fire before task completion.

7.4.3.2. Catching signal event
IntermediateSignalEvent
Figure 22. Catching signal event

A Signal Event can be used to respond to internal or external events during the execution of the process. A Signal Event should have one incoming connections and one outgoing connection. It specifies the type of event that is expected. Whenever that type of event is detected, the node connected to this event node will be triggered. It contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • EventType: The type of event that is expected.

  • VariableName: The name of the variable that will contain the data associated with this event (if any) when this event occurs.

A process instance can be signaled that a specific event occurred using

ksession.signalEvent(eventType, data, processInstanceId)

This will trigger all (active) signal event nodes in the given process instance that are waiting for that event type. Data related to the event can be passed using the data parameter. If the event node specifies a variable name, this data will be copied to that variable when the event occurs.

It is also possible to use event nodes inside sub-processes. These event nodes will however only be active when the sub-process is active.

You can also generate a signal from inside a process instance. A script (in a script task or using on entry or on exit actions) can use

kcontext.getKieRuntime().signalEvent(eventType, data, kcontext.getProcessInstance().getId());

A throwing signal event could also be used to model the signaling of an event.

7.5. Gateways

7.5.1. Diverging gateway

DivergingGateway
Figure 23. Diverging gateway

Allows you to create branches in your process. A Diverging Gateway should have one incoming connection and two or more outgoing connections. There are three types of gateway nodes currently supported:

  • AND or parallel means that the control flow will continue in all outgoing connections simultaneously.

  • XOR or exclusive means that exactly one of the outgoing connections will be chosen. The decision is made by evaluating the constraints that are linked to each of the outgoing connections. The constraint with the lowest priority number that evaluates to true is selected. Constraints can be specified using different dialects. Note that you should always make sure that at least one of the outgoing connections will evaluate to true at runtime (the engine will throw an exception at runtime if it cannot find at least one outgoing connection).

  • OR or inclusive means that all outgoing connections whose condition evaluates to true are selected. Conditions are similar to the exclusive gateway, except that no priorities are taken into account. Note that you should make sure that at least one of the outgoing connections will evaluate to true at runtime because the engine will throw an exception at runtime if it cannot determine an outgoing connection.

It contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • Type: The type of the split node, i.e., AND, XOR or OR (see above).

  • Constraints: The constraints linked to each of the outgoing connections (in case of an exclusive or inclusive gateway).

7.5.2. Converging gateway

ConvergingGateway
Figure 24. Converging gateway

Allows you to synchronize multiple branches. A Converging Gateway should have two or more incoming connections and one outgoing connection. There are three types of splits currently supported:

  • AND or parallel means that is will wait until all incoming branches are completed before continuing.

  • XOR or exclusive means that it continues as soon as one of its incoming branches has been completed. If it is triggered from more than one incoming connection, it will trigger the next node for each of those triggers.

  • OR or inclusive means that it continues as soon as all direct active paths of its incoming branches has been completed. This is complex merge behaviour that is described in BPMN2 specification but in most cases it means that OR join will wait for all active flows that started in OR split. Some advanced cases (including other gateways in between or repeatable timers) will be causing different "direct active path" calculation.

It contains the following properties:

  • Id: The id of the node (which is unique within one node container).

  • Name: The display name of the node.

  • Type: The type of the Join node, i.e. AND, OR or XOR.

7.6. Others

7.6.1. Variables

While the flow chart focuses on specifying the control flow of the process, it is usually also necessary to look at the process from a data perspective. Throughout the execution of a process, data can be retrieved, stored, passed on and used.

For storing runtime data, during the execution of the process, process variables can be used. A variable is defined by a name and a data type. This could be a basic data type, such as boolean, int, or String, or any kind of Object subclass (it must implement Serializable interface). Variables can be defined inside a variable scope. The top-level scope is the variable scope of the process itself. Subscopes can be defined using a Sub-Process. Variables that are defined in a subscope are only accessible for nodes within that scope.

Whenever a variable is accessed, the process will search for the appropriate variable scope that defines the variable. Nesting of variable scopes is allowed. A node will always search for a variable in its parent container. If the variable cannot be found, it will look in that one’s parent container, and so on, until the process instance itself is reached. If the variable cannot be found, a read access yields null, and a write access produces an error message, with the process continuing its execution.

Variables can be used in various ways:

  • Process-level variables can be set when starting a process by providing a map of parameters to the invocation of the startProcess method. These parameters will be set as variables on the process scope.

  • Script actions can access variables directly, simply by using the name of the variable as a local parameter in their script. For example, if the process defines a variable of type "org.jbpm.Person" in the process, a script in the process could access this directly:

    // call method on the process variable "person"
    person.setAge(10);

    Changing the value of a variable in a script can be done through the knowledge context:

    kcontext.setVariable(variableName, value);
  • Service tasks (and reusable sub-processes) can pass the value of process variables to the outside world (or another process instance) by mapping the variable to an outgoing parameter. For example, the parameter mapping of a service task could define that the value of the process variable x should be mapped to a task parameter y right before the service is being invoked. You can also inject the value of process variable into a hard-coded parameter String using \#{expression}. For example, the description of a human task could be defined as You need to contact person #{person.getName()} (where person is a process variable), which will replace this expression by the actual name of the person when the service needs to be invoked. Similarly results of a service (or reusable sub-process) can also be copied back to a variable using a result mapping.

  • Various other nodes can also access data. Event nodes for example can store the data associated to the event in a variable, etc. Check the properties of the different node types for more information.

  • Process variables can be accessed also from the Java code of your application. It is done by casting of ProcessInstance to WorkflowProcessInstance. See the following example:

    variable = ((WorkflowProcessInstance) processInstance).getVariable("variableName");

    To list all the process variables see the following code snippet:

    org.jbpm.process.instance.ProcessInstance processInstance = ...;
    VariableScopeInstance variableScope = (VariableScopeInstance) processInstance.getContextInstance(VariableScope.VARIABLE_SCOPE);
    Map<String, Object> variables = variableScope.getVariables();

    Note that when you use persistence then you have to use a command based approach to get all process variables:

    Map<String, Object> variables = ksession.execute(new GenericCommand<Map<String, Object>>() {
        public Map<String, Object> execute(Context context) {
            KieSession ksession = ((KnowledgeCommandContext) context).getStatefulKnowledgesession();
            org.jbpm.process.instance.ProcessInstance processInstance = (org.jbpm.process.instance.ProcessInstance) ksession.getProcessInstance(piId);
            VariableScopeInstance variableScope = (VariableScopeInstance) processInstance.getContextInstance(VariableScope.VARIABLE_SCOPE);
            Map<String, Object> variables = variableScope.getVariables();
            return variables;
        }
    });

Finally, processes (and rules) all have access to globals, i.e. globally defined variables and data in the Knowledge Session. Globals are directly accessible in actions just like variables. Globals need to be defined as part of the process before they can be used. You can for example define globals by clicking the globals button when specifying an action script in the Eclipse action property editor. You can also set the value of a global from the outside using ksession.setGlobal(name, value) or from inside process scripts using kcontext.getKieRuntime().setGlobal(name,value);.

7.6.2. Scripts

Action scripts can be used in different ways:

  • Within a Script Task,

  • As entry or exit actions, with a number of nodes.

Actions have access to globals and the variables that are defined for the process and the predefined variable kcontext. This variable is of type ProcessContext and can be used for several tasks:

  • Getting the current node instance (if applicable). The node instance could be queried for data, such as its name and type. You can also cancel the current node instance.

    NodeInstance node = kcontext.getNodeInstance();
    String name = node.getNodeName();
  • Getting the current process instance. A process instance can be queried for data (name, id, processId, etc.), aborted or signaled an internal event.

    ProcessInstance proc = kcontext.getProcessInstance();
    proc.signalEvent( type, eventObject );
  • Getting or setting the value of variables.

  • Accessing the Knowledge Runtime allows you do things like starting a process, signaling (external) events, inserting data, etc.

jBPM supports multiple dialects, like Java, JavaScript and MVEL. Java actions should be valid Java code, same for JavaScript. MVEL actions can use the business scripting language MVEL to express the action. MVEL accepts any valid Java code but additionally provides support for nested accesses of parameters (e.g., person.name instead of person.getName()), and many other scripting improvements. Thus, MVEL expressions are more convenient for the business user. For example, an action that prints out the name of the person in the "requester" variable of the process would look like this:

// Java dialect
System.out.println( person.getName() );

// JavaScript dialect
print(person.name + '\n);

//  MVEL dialect
System.out.println( person.name );

7.6.3. Constraints

Constraints can be used in various locations in your processes, for example in a diverging gateway. jBPM supports two types of constraints:

  • Code constraints are boolean expressions, evaluated directly whenever they are reached. We support multiple dialects for expressing these code constraints: Java, JavaScript and MVEL. All code constraints have direct access to the globals and variables defined in the process. Here is an example of a valid Java code constraint, person being a variable in the process:

    return person.getAge() > 20;

    A similar example of a valid MVEL code constraint is:

    return person.age > 20;

    And for JavaScript:

    person.age > 20
  • Rule constraints are equals to normal Drools rule conditions. They use the Drools Rule Language syntax to express possibly complex constraints. These rules can, like any other rule, refer to data in the Working Memory. They can also refer to globals directly. Here is an example of a valid rule constraint:

    Person( age > 20 )

    This tests for a person older than 20 being in the Working Memory.

Rule constraints do not have direct access to variables defined inside the process. It is however possible to refer to the current process instance inside a rule constraint, by adding the process instance to the Working Memory and matching for the process instance in your rule constraint. We have added special logic to make sure that a variable processInstance of type WorkflowProcessInstance will only match to the current process instance and not to other process instances in the Working Memory. Note that you are however responsible yourself to insert the process instance into the session and, possibly, to update it, for example, using Java code or an on-entry or on-exit or explicit action in your process. The following example of a rule constraint will search for a person with the same name as the value stored in the variable "name" of the process:

processInstance : WorkflowProcessInstance()
Person( name == ( processInstance.getVariable("name") ) )
# add more constraints here ...

7.6.4. Timers

Timers wait for a predefined amount of time, before triggering, once or repeatedly. They can be used to trigger certain logic after a certain period, or to repeat some action at regular intervals.

7.6.4.1. Configure timer with delay and period

A Timer node is set up with a delay and a period. The delay specifies the amount of time to wait after node activation before triggering the timer the first time. The period defines the time between subsequent trigger activations. A period of 0 results in a one-shot timer.

The (period and delay) expression should be of the form [d][#h][#m][#s][[ms]]. You can specify the amount of days, hours, minutes, seconds and milliseconds (which is the default if you don’t specify anything). For example, the expression "1h" will wait one hour before triggering the timer (again).

7.6.4.2. Configure timer with CRON like expression

Timer events can be configured with CRON like expression when timeCycle is used as timer event definition. Important is that the language attribute of timeCycle definition must be set to cron. With that such cycle of a timer is controlled in the same way as CRON jobs. CRON like expression is supported for:

  • start event timers

  • intermediate event timers

  • boundary event timers

Following is an example of a definition of a boundary timer with CRON like expression

<bpmn2:boundaryEvent id="1" name="Send Update Timer" attachedToRef="_77A94B54-8B7C-4F8A-84EE-C1D310A343A6" cancelActivity="false">
   <bpmn2:outgoing>2</bpmn2:outgoing>
   <bpmn2:timerEventDefinition id="_erIyiJZ7EeSDh8PHobjSSA">
     <bpmn2:timeCycle xsi:type="bpmn2:tFormalExpression" id="_erIyiZZ7EeSDh8PHobjSSA" language="cron">0/1 * * * * ?</bpmn2:timeCycle>
   </bpmn2:timerEventDefinition>
</bpmn2:boundaryEvent>

This timer will fire every second and will continue until activity this boundary event is attached to is active.

7.6.4.3. Configure timer ISO-8601 date format

since version 6 timers can be configured with valid ISO8601 date format that supports both one shot timers and repeatable timers. Timers can be defined as date and time representation, time duration or repeating intervals

  • Date - 2013-12-24T20:00:00.000+02:00 - fires exactly at Christmas Eve at 8PM

  • Duration - PT1S - fires once after 1 second

  • Repeatable intervals - R/PT1S - fires every second, no limit, alternatively R5/PT1S will fire 5 times every second

7.6.4.4. Configure timer with process variables

The timer service is responsible for making sure that timers get triggered at the appropriate times. Timers can also be canceled, meaning that the timer will no longer be triggered.

Timers can be used in two ways inside a process:

  • A Timer Event may be added to the process flow. Its activation starts the timer, and when it triggers, once or repeatedly, it activates the Timer node’s successor. Subsequently, the outgoing connection of a timer with a positive period is triggered multiple times. Canceling a Timer node also cancels the associated timer, after which no more triggers will occur.

  • Timers can be associated with a Sub-Process or tasks as a boundary event.

7.6.4.5. Update timer within running process instance

In some cases timer that has been already scheduled should be rescheduled to accomodate new requirements (prolong or shorten timer expiration time, change delay, period or repeat limit).

As this involves several low level steps, jBPM comes with a dedicated command to perform these operations as atomic operation to make sure all is done within same transaction.

org.jbpm.process.instance.command.UpdateTimerCommand

Following timer events are supported to be updated:

  • boundary timer event

  • intermediate timer event

Timers can be rescheduled by providing following information to the UpdateTimerCommand

  • processInstanceId - mandatory

  • timer node name - mandatory

Next one of following three parameters set needs to be used:

  • delay

  • period and repeatLimit

  • delay, period and repeatLimit

Example on how to updated timer event:

// first start process instance and record its id
long id = kieSession.startProcess(BOUNDARY_PROCESS_NAME).getId();

//set timer delay to 3s
kieSession.execute(new UpdateTimerCommand(id, BOUNDARY_TIMER_ATTACHED_TO_NAME, 3));

Important is that the update command is executed via ksession executor to ensure it’s done in transaction (when persistence is used).

7.7. Process Fluent API

While it is recommended to define processes using the graphical editor or the underlying XML (to shield yourself from internal APIs), it is also possible to define a process using the Process API directly. The most important process model elements are defined in the packages org.jbpm.workflow.core and org.jbpm.workflow.core.node. A "fluent API" is provided that allows you to easily construct processes in a readable manner using factories. At the end, you can validate the process that you were constructing manually.

7.7.1. Example

This is a simple example of a basic process with a script task only:

RuleFlowProcessFactory factory =
    RuleFlowProcessFactory.createProcess("org.jbpm.HelloWorld");
factory
    // Header
    .name("HelloWorldProcess")
    .version("1.0")
    .packageName("org.jbpm")
    // Nodes
    .startNode(1).name("Start").done()
    .actionNode(2).name("Action")
        .action("java", "System.out.println(\"Hello World\");").done()
    .endNode(3).name("End").done()
    // Connections
    .connection(1, 2)
    .connection(2, 3);
RuleFlowProcess process = factory.validate().getProcess();

KieServices ks = KieServices.Factory.get();
KieFileSystem kfs = ks.newKieFileSystem();
Resource resource = ks.getResources().newByteArrayResource(
    XmlBPMNProcessDumper.INSTANCE.dump(process).getBytes());
resource.setSourcePath("helloworld.bpmn2");
kfs.write(resource);
ReleaseId releaseId = ks.newReleaseId("org.jbpm", "helloworld", "1.0");
kfs.generateAndWritePomXML(releaseId);
ks.newKieBuilder(kfs).buildAll();
ks.newKieContainer(releaseId).newKieSession().startProcess("org.jbpm.HelloWorld");

You can see that we start by calling the static createProcess() method from the RuleFlowProcessFactory class. This method creates a new process with the given id and returns the RuleFlowProcessFactory that can be used to create the process. A typical process consists of three parts. The header part comprises global elements like the name of the process, imports, variables, etc. The nodes section contains all the different nodes that are part of the process. The connections section finally links these nodes to each other to create a flow chart.

In this example, the header contains the name and the version of the process and the package name. After that, you can start adding nodes to the current process. If you have auto-completion you can see that you have different methods to create each of the supported node types at your disposal.

When you start adding nodes to the process, in this example by calling the startNode(), actionNode() and endNode() methods, you can see that these methods return a specific NodeFactory, that allows you to set the properties of that node. Once you have finished configuring that specific node, the done() method returns you to the current RuleFlowProcessFactory so you can add more nodes, if necessary.

When you are finished adding nodes, you must connect them by creating connections between them. This can be done by calling the method connection, which will link previously created nodes.

Finally, you can validate the generated process by calling the validate() method and retrieve the created RuleFlowProcess object.

7.8. Testing

Even though business processes aren’t code (we even recommend you to make them as high-level as possible and to avoid adding implementation details), they also have a life cycle like other development artefacts. And since business processes can be updated dynamically, testing them (so that you don’t break any use cases when doing a modification) is really important as well.

7.8.1. Unit testing

When unit testing your process, you test whether the process behaves as expected in specific use cases, for example test the output based on the existing input. To simplify unit testing, jBPM includes a helper class called JbpmJUnitBaseTestCase (in the jbpm-test module) that you can use to greatly simplify your JUnit testing, by offering:

  • helper methods to create a new RuntimeManager and RuntimeEngine for a given (set of) process(es)

    • you can select whether you want to use persistence or not

  • assert statements to check

    • the state of a process instance (active, completed, aborted)

    • which node instances are currently active

    • which nodes have been triggered (to check the path that has been followed)

    • get the value of variables

For example, consider the following "hello world" process containing a start event, a script task and an end event. The following JUnit test will create a new session, start the process and then verify whether the process instance completed successfully and whether these three nodes have been executed.

HelloWorld
public class ProcessPersistenceTest extends JbpmJUnitBaseTestCase {

    public ProcessPersistenceTest() {
        // setup data source, enable persistence
        super(true, true);
    }

    @Test
    public void testProcess() {
        // create runtime manager with single process - hello.bpmn
        createRuntimeManager("hello.bpmn");

        // take RuntimeManager to work with process engine
        RuntimeEngine runtimeEngine = getRuntimeEngine();

        // get access to KieSession instance
        KieSession ksession = runtimeEngine.getKieSession();

        // start process
        ProcessInstance processInstance = ksession.startProcess("com.sample.bpmn.hello");

        // check whether the process instance has completed successfully
        assertProcessInstanceCompleted(processInstance.getId(), ksession);

        // check what nodes have been triggered
        assertNodeTriggered(processInstance.getId(), "StartProcess", "Hello", "EndProcess");
    }
}

JbpmJUnitBaseTestCase acts as base test case class that shall be used for jBPM related tests. It provides four usage areas:

  • JUnit life cycle methods

    • setUp: executed @Before and configures data source and EntityManagerFactory, cleans up Singleton’s session id

    • tearDown: executed @After and clears out history, closes EntityManagerFactory and data source, disposes RuntimeEngines and RuntimeManager

  • Knowledge Base and KnowledgeSession management methods

    • createRuntimeManager creates RuntimeManager for given set of assets and selected strategy

    • disposeRuntimeManager disposes RuntimeManager currently active in the scope of test

    • getRuntimeEngine creates new RuntimeEngine for given context

  • Assertions

    • assertProcessInstanceCompleted

    • assertProcessInstanceAborted

    • assertProcessInstanceActive

    • assertNodeActive

    • assertNodeTriggered

    • assertProcessVarExists

    • assertNodeExists

    • assertVersionEquals

    • assertProcessNameEquals

  • Helper methods

    • getDs - returns currently configured data source

    • getEmf - returns currently configured EntityManagerFactory

    • getTestWorkItemHandler - returns test work item handler that might be registered in addition to what is registered by default

    • clearHistory - clears history log

    • setupPoolingDataSource - sets up data source

JbpmJUnitBaseTestCase supports all three predefined RuntimeManager strategies as part of the unit testing. It’s enough to specify which strategy shall be used whenever creating runtime manager as part of single test:

public class ProcessHumanTaskTest extends JbpmJUnitBaseTestCase {

    private static final Logger logger = LoggerFactory.getLogger(ProcessHumanTaskTest.class);

    public ProcessHumanTaskTest() {
        super(true, false);
    }

    @Test
    public void testProcessProcessInstanceStrategy() {
        RuntimeManager manager = createRuntimeManager(Strategy.PROCESS_INSTANCE, "manager", "humantask.bpmn");
        RuntimeEngine runtimeEngine = getRuntimeEngine(ProcessInstanceIdContext.get());
        KieSession ksession = runtimeEngine.getKieSession();
        TaskService taskService = runtimeEngine.getTaskService();

        int ksessionID = ksession.getId();
        ProcessInstance processInstance = ksession.startProcess("com.sample.bpmn.hello");

        assertProcessInstanceActive(processInstance.getId(), ksession);
        assertNodeTriggered(processInstance.getId(), "Start", "Task 1");

        manager.disposeRuntimeEngine(runtimeEngine);
        runtimeEngine = getRuntimeEngine(ProcessInstanceIdContext.get(processInstance.getId()));

        ksession = runtimeEngine.getKieSession();
        taskService = runtimeEngine.getTaskService();

        assertEquals(ksessionID, ksession.getId());

        // let john execute Task 1
        List<TaskSummary> list = taskService.getTasksAssignedAsPotentialOwner("john", "en-UK");
        TaskSummary task = list.get(0);
        logger.info("John is executing task {}", task.getName());
        taskService.start(task.getId(), "john");
        taskService.complete(task.getId(), "john", null);

        assertNodeTriggered(processInstance.getId(), "Task 2");

        // let mary execute Task 2
        list = taskService.getTasksAssignedAsPotentialOwner("mary", "en-UK");
        task = list.get(0);
        logger.info("Mary is executing task {}", task.getName());
        taskService.start(task.getId(), "mary");
        taskService.complete(task.getId(), "mary", null);

        assertNodeTriggered(processInstance.getId(), "End");
        assertProcessInstanceCompleted(processInstance.getId(), ksession);
    }
}

Above is more complete example that uses PerProcessInstance runtime manager strategy and uses task service to deal with user tasks.

7.8.1.1. Testing integration with external services

Real-life business processes typically include the invocation of external services (like for example a human task service, an email server or your own domain-specific services). One of the advantages of our domain-specific process approach is that you can specify yourself how to actually execute your own domain-specific nodes, by registering a handler. And this handler can be different depending on your context, allowing you to use testing handlers for unit testing your process. When you are unit testing your business process, you can register test handlers that then verify whether specific services are requested correctly, and provide test responses for those services. For example, imagine you have an email node or a human task as part of your process. When unit testing, you don’t want to send out an actual email but rather test whether the email that is requested contains the correct information (for example the right to email, a personalized body, etc.).

A TestWorkItemHandler is provided by default that can be registered to collect all work items (a work item represents one unit of work, like for example sending one specific email or invoking one specific service and contains all the data related to that task) for a given type. This test handler can then be queried during unit testing to check whether specific work was actually requested during the execution of the process and that the data associated with the work was correct.

The following example describes how a process that sends out an email could be tested. This test case in particular will test whether an exception is raised when the email could not be sent (which is simulated by notifying the engine that the sending the email could not be completed). The test case uses a test handler that simply registers when an email was requested (and allows you to test the data related to the email like from, to, etc.). Once the engine has been notified the email could not be sent (using abortWorkItem(..)), the unit test verifies that the process handles this case successfully by logging this and generating an error, which aborts the process instance in this case.

HelloWorld2
public void testProcess2() {

    // create runtime manager with single process - hello.bpmn
    createRuntimeManager("sample-process.bpmn");
    // take RuntimeManager to work with process engine
    RuntimeEngine runtimeEngine = getRuntimeEngine();

    // get access to KieSession instance
    KieSession ksession = runtimeEngine.getKieSession();

    // register a test handler for "Email"
    TestWorkItemHandler testHandler = getTestWorkItemHandler();

    ksession.getWorkItemManager().registerWorkItemHandler("Email", testHandler);

    // start the process
    ProcessInstance processInstance = ksession.startProcess("com.sample.bpmn.hello2");

    assertProcessInstanceActive(processInstance.getId(), ksession);
    assertNodeTriggered(processInstance.getId(), "StartProcess", "Email");

    // check whether the email has been requested
    WorkItem workItem = testHandler.getWorkItem();
    assertNotNull(workItem);
    assertEquals("Email", workItem.getName());
    assertEquals("me@mail.com", workItem.getParameter("From"));
    assertEquals("you@mail.com", workItem.getParameter("To"));

    // notify the engine the email has been sent
    ksession.getWorkItemManager().abortWorkItem(workItem.getId());
    assertProcessInstanceAborted(processInstance.getId(), ksession);
    assertNodeTriggered(processInstance.getId(), "Gateway", "Failed", "Error");

}
7.8.1.2. Configuring persistence

You can configure whether you want to execute the JUnit tests using persistence or not. By default, the JUnit tests will use persistence, meaning that the state of all process instances will be stored in a (in-memory H2) database (which is started by the JUnit test during setup) and a history log will be used to check assertions related to execution history. When persistence is not used, process instances will only live in memory and an in-memory logger is used for history assertions.

Persistence (and setup of data source) is controlled by the super constructor and allows following

  • default, no arg constructor - the most simple test case configuration (does NOT initialize data source and does NOT configure session persistence) - this is usually used for in memory process management, without human task interaction

  • super(boolean, boolean) - allows to explicitly configure persistence and data source. This is the most common way of bootstrapping test cases for jBPM

    • super(true, false) - to execute with in memory process management with human tasks persistence

    • super(true, true) - to execute with persistent process management with human tasks persistence

  • super(boolean, boolean, string) - same as super(boolean, boolean) but allows to use another persistence unit name than default (org.jbpm.persistence.jpa)

public class ProcessHumanTaskTest extends JbpmJUnitBaseTestCase {

    private static final Logger logger = LoggerFactory.getLogger(ProcessHumanTaskTest.class);

    public ProcessHumanTaskTest() {
        // configure this tests to not use persistence for process engine but still use it for human tasks
        super(true, false);
    }
}

8. Human Tasks

8.1. Introduction

An important aspect of business processes is human task management. While some of the work performed in a process can be executed automatically, some tasks need to be executed by human actors.

jBPM supports a special human task node inside processes for modeling this interaction with human users. This human task node allows process designers to define the properties related to the task that the human actor needs to execute, like for example the type of task, the actor(s), or the data associated with the task.

jBPM also includes a so-called human task service, a back-end service that manages the life cycle of these tasks at runtime. The jBPM implementation is based on the WS-HumanTask specification. Note however that this implementation is fully pluggable, meaning that users can integrate their own human task solution if necessary.

In order to have human actors participate in your processes, you first need to (1) include human task nodes inside your process to model the interaction with human actors, (2) integrate a task management component (like for example the WS-HumanTask based implementation provided by jBPM) and (3) have end users interact with a human task client to request their task list and claim and complete the tasks assigned to them. Each of these three elements will be discussed in more detail in the next sections.

8.2. Using User Tasks in our Processes

jBPM supports the use of human tasks inside processes using a special User Task node defined by the BPMN2 Specification(as shown in the figure above). A User Task node represents an atomic task that needs to be executed by a human actor.

user task

[Although jBPM has a special user task node for including human tasks inside a process, human tasks are considered the same as any other kind of external service that needs to be invoked and are therefore simply implemented as a domain-specific service. See the chapter on domain-specific processes to learn more about this.]

A User Task node contains the following core properties:

  • Actors: The actors that are responsible for executing the human task. A list of actor id’s can be specified using a comma (',') as separator.

  • Group: The group id that is responsible for executing the human task. A list of group id’s can be specified using a comma (',') as separator.

  • Name: The display name of the node.

  • TaskName: The name of the human task. This name is used to link the task to a Form. It also represent the internal name of the Task that can be used for other purposes.

  • DataInputSet: all the input variables that the task will receive to work on. Usually you will be interested in copying variables from the scope of the process to the scope of the task. (Look at the data mappings section for an example)

  • DataOutputSet: all the output variables that will be generated by the execution of the task. Here you specify all the name of the variables in the context of the task that you are interested to copy to the context of the process. (Look at the data mappings section for an example)

  • Assignments: here you specify which process variable will be linked to each Data Input and Data Output mapping. (Look at the data mappings section for an example)

You can edit these variables in the properties view (see below) when selecting the User Task node.

properties panel

A User Task node also contains the following extra properties:

  • Comment: A comment associated with the human task. Here you can use expressions.

  • Content: The data associated with this task.

  • Priority: An integer indicating the priority of the human task.

  • Skippable: Specifies whether the human task can be skipped, i.e., whether the actor may decide not to execute the task.

  • On entry and on exit actions: Action scripts that are executed upon entry and exit of this node, respectively.

properties panel extra

8.2.1. Swimlanes

User tasks can be used in combination with swimlanes to assign multiple human tasks to the same actor. Whenever the first task in a swimlane is created, and that task has an actorId specified, that actorId will be assigned to (all other tasks of) that swimlane as well. Note that this would override the actorId of subsequent tasks in that swimlane (if specified), so only the actorId of the first human task in a swimlane will be taken into account, all others will then take the actorId as assigned in the first one.

ActorId assignment will work only when there is single actor specified. Since ActorId field can contain multiple actors (john,mary,peter) auto assignment for the first task will not be performed when multiple values are found.

Whenever a human task that is part of a swimlane is completed, the actorId of that swimlane is set to the actorId that executed that human task. This allows for example to assign a human task to a group of users, and to assign future tasks of that swimlame to the user that claimed the first task. This will also automatically change the assignment of tasks if at some point one of the tasks is reassigned to another user.

8.3. Data Mappings

Human tasks typically present some data related to the task that needs to be performed to the actor that is executing the task and usually also request the actor to provide some result data related to the execution of the task. Task forms are typically used to present this data to the actor and request results.

The data that will be used by the Task needs to be specified when we define the User Task in our Process. In order to do that we need to define which data will be copied from the process context to the task context. Notice that the data is copied, so it can be modified inside the Task context but it will not affect the process variables unless we decide to copy back the value from the task to the process context.

Most of the times Forms are used to display data to the end user. Allowing them to generate/create new data that will be propagated to the process context to be used by future activities. In order to decide how the information flow from the process to a particular task and from the task to the process we need to define which pieces of information will be automatically copied by the process engine. The following sections shows how to do these mappings by configuring the DataInputSet, DataOutputSet and the Assignments properties of a User Task.

Let’s start defining the Task DataInputSet:

data input

Both GroupId and Comment are automatically generated, so you don’t need to worry about that. In this case the only user defined Data Input is called: in_name. This means that the task will be receiving information from the process context and internally this variable will be called in_name. The type is also specified here.

In the Data Outputs represent the data that will be generated by the tasks. In this case we have two variables of type String called: out_name and out_mail and two Integer variables called: out_age and out_score are defined. This means that inside the task context we will need to set the value to these variables.

data output

Finally all the connections with the process context needs to be done in the Data Assignments. The main idea here is to define how Data Inputs and Data Outputs will be associated with process variables.

data assignments

As shown in the previous screenshot, the assignments between the process variables (in this case (name, age, mail and hr_score)) and the Data Inputs and Outputs are done in the Data Assignments screen. Notice that the example uses a convention that makes it easy to know which is an internal Task variables (Data Input/Output) using the "in_" and "out_" prefix to the variable names. Using this convention you can quickly understand the Assignments screen. The first row maps the process variable called name to the data input called in_name. The second row maps the data output called out_mail to the process variable called mail, and so on.

These mappings at runtime will automatically copy the variables content from one context (process and task) to the other automatically for us.

8.4. Task Lifecycle

From the perspective of a process, when a user task node is encountered during the execution, a human task is created. The process will then only leave the user task node when the associated human task has been completed or aborted.

The human task itself usually has a complete life cycle itself as well. For details beyond what is described below, please check out the WS-HumanTask specification. The following diagram is from the WS-HumanTask specification and describes the human task life cycle.

WSHT lifecycle

A newly created task starts in the "Created" stage. Usually, it will then automatically become "Ready", after which the task will show up on the task list of all the actors that are allowed to execute the task. The task will stay "Ready" until one of these actors claims the task, indicating that he or she will be executing it.

When a user then eventually claims the task, the status will change to "Reserved". Note that a task that only has one potential (specific) actor will automatically be assigned to that actor upon creation of the task. When the user who has claimed the task starts executing it, the task status will change from "Reserved" to "InProgress".

Lastly, once the user has performed and completed the task, the task status will change to "Completed". In this step, the user can optionally specify the result data related to the task. If the task could not be completed, the user could also indicate this by using a fault response, possibly including fault data, in which case the status would change to "Failed".

While the life cycle explained above is the normal life cycle, the specification also describes a number of other life cycle methods, including:

  • Delegating or forwarding a task, so that the task is assigned to another actor

  • Revoking a task, so that it is no longer claimed by one specific actor but is (re)available to all actors allowed to take it

  • Temporarly suspending and resuming a task

  • Stopping a task in progress

  • Skipping a task (if the task has been marked as skippable), in which case the task will not be executed

8.5. Task Permissions

Only users associated with a specific task are allowed to modify or retrieve information about the task. This allows users to create a jBPM workflow with multiple tasks and yet still be assured of both the confidentiality and integrity of the task status and information associated with a task.

Some task operations will end up throwing a org.jbpm.services.task.exception.PermissionDeniedException when used with information about an unauthorized user. For example, when a user is trying to directly modify the task (for example, by trying to claim or complete the task), the PermissionDeniedException will be thrown if that user does not have the correct role for that operation. Furthermore, a user will not be able to view or retrieve tasks that the user is not involved with, especially if this is via the jBPM Console or KIE Workbench applications.

User 'Administrator' and group 'Administrators' are automatically added to each Human Task.

8.5.1. Task Permissions Matrix

The permisions matrix below summarizes the actions that specific user roles are allowed to do. On the left side, possible operations are listed while user roles are listed across the top of the matrix.

The cells of the permissions matrix contain one of three possible characters, each of which indicate the user role permissions for that operation:

  • a "+ indicates that the user role CAN do the specified operation

  • a “-” indicates that the user role MAY NOT do the specified operation

  • a “0” indicates that the user role MAY NOT do the specified operation, and that it is also not an operation that matches the user’s role ("not applicable")

Furthermore, the following words or abbreviations in the table header refer to the following roles:

Table 7. Task roles in the permissions table
Word Role Description

Initiator

Task Initiator

The user who creates the task instance

Stakeholder

Task Stakeholder

The user involved in the task: this user can influence the progress of a task, by performing administrative actions on the task instance

Potential

Potential Owner

The user who can claim the task before it has been claimed, or after it has been released or forward: only tasks that have the status "Ready" may be claimed; a potential owner becomes the actual owner of a task by claiming the task

Actual

Actual Owner

The user who has claimed the task and will progress the task to completion or failure

Administrator

Business Adminstrator

A "super user" who may modify the status or progress of a task at any point in a task’s lifecycle

User roles are assigned to users by the definition of the task in the jBPM (BPMN2) process definition.

Permissions Matrices

The following matrix describes the authorizations for all operations which modify a task:

Table 8. Main operations permissions matrix
Operation Role Initiator Stakeholder Potential Actual Administrator

activate

+

+

0

0

+

claim

-

+

+

0

+

complete

-

+

0

+

+

delegate

+

+

+

+

+

fail

-

+

0

+

+

forward

+

+

+

+

+

nominate

+

+

+

+

+

release

+

+

+

+

+

remove

-

0

0

0

+

resume

+

+

+

+

+

skip

+

+

+

+

+

start

-

+

+

+

+

stop

-

+

0

+

+

suspend

+

+

+

+

+

The matrix below describes the authorizations used when retrieving task information. In short, it says that all users which have any role with regards to the specific task, are allowed to see the task. This applies to all operations that are used to retrieve any type of information about the task.

Table 9. Retrieval operations permissions matrix
Operation Role Initiator Stakeholder Potential Actual Administrator

get

+

+

+

+

+

8.6. Task Service and The Process Engine

As far as the jBPM engine is concerned, human tasks are similar to any other external service that needs to be invoked and are implemented as a domain-specific service. (For more on domain-specific services, see the chapter on them here.) Because a human task is an example of such a domain-specific service, the process itself only contains a high-level, abstract description of the human task to be executed and a work item handler that is responsible for binding this (abstract) task to a specific implementation.

Users can plug in any human task service implementation, such as the one that’s provided by jBPM, or they may register their own implementation. In the next paragraphs, we will describe the human task service implementation provided by jBPM.

The jBPM project provides a default implementation of a human task service based on the WS-HumanTask specification. If you do not need to integrate jBPM with another existing implementation of a human task service, you can use this service. The jBPM implementation manages the life cycle of the tasks (creation, claiming, completion, etc.) and stores the state of all the tasks, task lists, and other associated information. It also supports features like internationalization, calendar integration, different types of assignments, delegation, escalation and deadlines. The code for the implementation itself can be found in the jbpm-human-task module.

The jBPM task service implementation is based on the WS-HumanTask (WS-HT) specification. This specification defines (in detail) the model of the tasks, the life cycle, and many other features. It is very comprehensive and the first version can be found here.

8.7. Task Service API

The human task service exposes a Java API for managing the life cycle of tasks. This allows clients to integrate (at a low level) with the human task service. Note that end users should probably not interact with this low-level API directly, but use one of the more user-friendly task clients (see below) instead. These clients offer a graphical user interface to request task lists, claim and complete tasks, and manage tasks in general. The task clients listed below use the Java API to internally interact with the human task service. Of course, the low-level API is also available so that developers can use it in their code to interact with the human task service directly.

A task service (interface org.kie.api.task.TaskService) offers the following methods (among others) for managing the life cycle of human tasks:

              ...

              void start( long taskId, String userId );

              void stop( long taskId, String userId );

              void release( long taskId, String userId );

              void suspend( long taskId, String userId );

              void resume( long taskId, String userId );

              void skip( long taskId, String userId );

              void delegate(long taskId, String userId, String targetUserId);

              void complete( long taskId, String userId, Map<String, Object> results );

              ...

If you take a look at the method signatures you will notice that almost all of these methods take the following arguments:

  • taskId: The id of the task that we are working with. This is usually extracted from the currently selected task in the user task list in the user interface.

  • userId: The id of the user that is executing the action. This is usually the id of the user that is logged in into the application.

There is also an internal interface that you should check for more methods to interact with the Task Service, this interface is internal until it gets tested. Future version of the External (public) interface can include some of the methods proposed in the InternalTaskService interface. If you want to make use of the methods provided by this interface you need to manually cast to InternalTaskService. One method that can be useful from this interface is getTaskContent():

               Map<String, Object> getTaskContent( long taskId );

This method saves you from doing all the boiler plate of getting the ContentMarshallerContext to unmarshall the serialized version of the task content. If you only want to use the stable/public API’s you can just copy what this method does:

              Task taskById = taskQueryService.getTaskInstanceById(taskId);
              Content contentById = taskContentService.getContentById(taskById.getTaskData().getDocumentContentId());
              ContentMarshallerContext context = getMarshallerContext(taskById);
              Object unmarshalledObject = ContentMarshallerHelper.unmarshall(contentById.getContent(), context.getEnvironment(), context.getClassloader());
              if (!(unmarshalledObject instanceof Map)) {
                  throw new IllegalStateException(" The Task Content Needs to be a Map in order to use this method and it was: "+unmarshalledObject.getClass());

              }
              Map<String, Object> content = (Map<String, Object>) unmarshalledObject;
              return content;

Because the content of the Task can be any Object, the previous method assume that you are storing a Map of objects to work. If you are storing other than a Map you should do the correspondent checks.

8.7.1. Task event listener

Task service supports task listeners to be invoked upon various life cycle events happening on given task instance. In majority of cases task event listeners are used to intercept certain operation to perform additional logic - like storing task information in separate tables for business activity monitoring needs.

Task event listeners are pluggable and users can provide their own implementation of org.kie.api.task.TaskLifeCycleEventListener interface. There are beforeTask* and afterTask* methods that are invoked upon given event occured on a task instance.

TaskEvent (org.kie.api.task.TaskEvent) is the only argument available to the listener that provides access to:

  • Task instance that the event correspond to

  • TaskContext that provides access to services for further processing needs such as TaskPersistenceContext

In many cases implementors of task event listener need to have access to task variables (either input or output or both) to perform required operations. It can be done as described above (using various services and content marshaller helper) though that in many cases leads to code duplication in multiple listeners thus an extended support was added in 6.5 to simply use TaskContext to obtain that information.

loadTaskVariables(Task task);

Method loadTaskVariables can be used to populate both input and output variables of a given task by simple and single method call. That method is "no op" in case task variables are already set on a task.

To improve performance task variables are automatically set when they are available - usually given by caller on task service:

  • when task is created it usually has input variables, these variables are then set on Task instance so there is no need to use loadTaskVariables method as only task input variables are available when task is being created - applies to beforeTaskAdded and afterTaskAdded events handling

  • when task is completed it usually has output variables, these variables are set on a task so there is no need to use loadTaskVariables method if only task output variables are required.

Other than that loadTaskVariables should be used to populate task variables.

It’s enough to call it once (like in beforeTask) method of the listener as they will be available to both beforeTask* and afterTask* methods then.

8.7.2. Data model of task service

Below is the data base model used by task service with all tables and their relationship illustrated.

task schema

8.8. Interacting with the Task Service

In order to get access to the Task Service API it is recommended to let the Runtime Manager to make sure that everything is setup correctly. Look at the Runtime Manager section for more information. From the API perspective you should be doing something like this:

// ...

RuntimeEngine engine = runtimeManager.getRuntimeEngine(EmptyContext.get());
KieSession kieSession = engine.getKieSession();
// Start a process
kieSession.startProcess("CustomersRelationship.customers", params);
// Do Task Operations
TaskService taskService = engine.getTaskService();
List<TaskSummary> tasksAssignedAsPotentialOwner = taskService.getTasksAssignedAsPotentialOwner("mary", "en-UK");

// Claim Task
taskService.claim(taskSummary.getId(), "mary");
// Start Task
taskService.start(taskSummary.getId(), "mary");

// ...

If you use this approach, there is no need to register the Task Service with the Process Engine. The Runtime Manager will do that for you automatically. If you don’t use the Runtime Manager, you will be responsible for setting the LocalHTWorkItemHandler in the session in order to get the Task Service notifying the Process Engine when a task is completed, or the Process Engine notifying that a task has been created.

In jBPM 6.x the Task Service runs locally to the Process and Rule Engine and for that reason multiple light clients can be created for different Process and Rule Engine’s instances. All the clients will be sharing the same database (backend storage for the tasks).

8.9. Experimental features

8.9.1. SubTasks

The "Subtasks" feature is an experimental feature in the task service. This feature allows one task to have sub-tasks in a parent-child relationship. The parent task can auto-complete depending on the state of its children (and the subtask strategy used).

You can use it by setting the parentId of a task, either when creating the task manually via the task service or otherwise by setting the ParentId parameter of the task definition in the BPMN2 process definition.

9. Persistence and Transactions

9.1. Process Instance State

jBPM allows the persistent storage of certain information. This chapter describes these different types of persistence and how to configure them. An example of the information stored is the process runtime state. Storing the process runtime state is necessary in order to be able to continue execution of a process instance at any point, if something goes wrong. Also, the process definitions themselves, and the history information (logs of current and previous process states) can also be persisted.

9.1.1. Runtime State

Whenever a process is started, a process instance is created, which represents the execution of the process in that specific context. For example, when executing a process that specifies how to process a sales order, one process instance is created for each sales request. The process instance represents the current execution state in that specific context, and contains all the information related to that process instance. Note that it only contains the (minimal) runtime state that is needed to continue the execution of that process instance at some later time, but it does not include information about the history of that process instance if that information is no longer needed in the process instance.

The runtime state of an executing process can be made persistent, for example, in a database. This allows to restore the state of execution of all running processes in case of unexpected failure, or to temporarily remove running instances from memory and restore them at some later time. jBPM allows you to plug in different persistence strategies. By default, if you do not configure the process engine otherwise, process instances are not made persistent.

If you configure the engine to use persistence, it will automatically store the runtime state into the database. You do not have to trigger persistence yourself, the engine will take care of this when persistence is enabled. Whenever you invoke the engine, it will make sure that any changes are stored at the end of that invocation, at so-called safe points. Whenever something goes wrong and you restore the engine from the database, you also should not reload the process instances and trigger them manually to resume execution, as process instances will automatically resume execution if they are triggered, like for example by a timer expiring, the completion of a task that was requested by that process instance, or a signal being sent to the process instance. The engine will automatically reload process instances on demand.

The runtime persistence data should in general be considered internal, meaning that you probably should not try to access these database tables directly and especially not try to modify these directly (as changing the runtime state of process instances without the engine knowing might have unexpected side-effects). In most cases where information about the current execution state of process instances is required, the use of a history log is mostly recommended (see below). In some cases, it might still be useful to for example query the internal database tables directly, but you should only do this if you know what you are doing.

9.1.1.1. Binary Persistence

jBPM uses a binary persistence mechanism, otherwise known as marshalling, which converts the state of the process instance into a binary dataset. When you use persistence with jBPM, this mechanism is used to save or retrieve the process instance state from the database. The same mechanism is also applied to the session state and any work item states.

When the process instance state is persisted, two things happen:

  • First, the process instance information is transformed into a binary blob. For performance reasons, a custom serialization mechanism is used and not normal Java serialization.

  • This blob is then stored, alongside other metadata about this process instance. This metadata includes, among other things, the process instance id, process id, and the process start date.

Apart from the process instance state, the session itself can also store some state, such as the state of timer jobs, or the session data that any business rules would be evaluated over. This session state is stored separately as a binary blob, along with the id of the session and some metadata. You can always restore session state by reloading the session with the given id. The session id can be retrieved using ksession.getId().

Note that the process instance binary datasets are usually relatively small, as they only contain the minimal execution state of the process instance. For a simple process instance, this usually contains one or a few node instances, i.e., any node that is currently executing, and any existing variable values.

As a result of jBPM using marshalling, the data model is both simple and small.

jBPM data model

image::Persistence/jbpm_schema.png

The sessioninfo entity contains the state of the (knowledge) session in which the jBPM process instance is running.

Table 10. SessionInfo
Field Description Nullable

id

The primary key.

NOT NULL

lastmodificationdate

The last time that the entity was saved to the database

rulesbytearray

The binary dataset containing the state of the session

NOT NULL

startdate

The start time of the session

optlock

The version field that serves as its optimistic lock value

The processinstanceinfo entity contains the state of the jBPM process instance.

Table 11. ProcessInstanceInfo
Field Description Nullable

instanceid

The primary key

NOT NULL

lastmodificationdate

The last time that the entity was saved to the database

lastreaddate

The last time that the entity was retrieved (read) from the database

processid

The name (id) of the process

processinstancebytearray

This is the binary dataset containing the state of the process instance

NOT NULL

startdate

The start time of the process

state

An integer representing the state of the process instance

NOT NULL

optlock

The version field that serves as its optimistic lock value

The eventtypes entity contains information about events that a process instance will undergo or has undergone.

Table 12. EventTypes
Field Description Nullable

instanceid

This references the processinstanceinfo primary key and there is a foreign key constraint on this column.

NOT NULL

eventTypes

A text field related to an event that the process has undergone.

The workiteminfo entity contains the state of a work item.

Table 13. WorkItemInfo
Field Description Nullable

workitemid

The primary key

NOT NULL

creationDate

The creation date of the work item

name

The name of the work item

processinstanceid

The (primary key) id of the process: there is no foreign key constraint on this field.

NOT NULL

state

An integer representing the state of the work item

NOT NULL

optlock

The version field that serves as its optimistic lock value

workitembytearay

This is the binary dataset containing the state of the work item

NOT NULL

The CorrelationKeyInfo entity contains information about correlation keys assigned to given process instance - loose relationship as this table is considered optional used only when correlation capabilities are required.

Table 14. CorrelationKeyInfo
Field Description Nullable

keyid

The primary key

NOT NULL

name

assigned name of the correlation key

processinstanceid

The id of the process instance which is assigned to this correlation key

NOT NULL

optlock

The version field that serves as its optimistic lock value

The CorrelationPropertyInfo entity contains information about correlation properties for given correlation key that is assigned to given process instance.

Table 15. CorrelationPropertyInfo
Field Description Nullable

propertyid

The primary key

NOT NULL

name

The name of the property

value

The value of the property

NOT NULL

optlock

The version field that serves as its optimistic lock value

correlationKey-keyid

Foregin key to map to correlation key

NOT NULL

The ContextMappingInfo entity contains information about contextual information mapped to ksession. This is an internal part of RuntimeManager and can be considered optional when RuntimeManager is not used.

Table 16. ContextMappingInfo
Field Description Nullable

mappingid

The primary key

NOT NULL

context_id

Identifier of the context

NOT NULL

ksession_id

Identifier of the ksession mapped to this context

NOT NULL

optlock

The version field that serves as its optimistic lock value

9.1.1.2. Safe Points

The state of a process instance is stored at so-called "safe points" during the execution of the process engine. Whenever a process instance is executing (for example when it started or continuing from a previous wait state, the engine executes the process instance until no more actions can be performed (meaning that the process instance either has completed (or was aborted), or that it has reached a wait state in all of its parallel paths). At that point, the engine has reached the next safe state, and the state of the process instance (and all other process instances that might have been affected) is stored persistently.

9.2. Audit Log

In many cases it will be useful (if not necessary) to store information about the execution of process instances, so that this information can be used afterwards. For example, sometimes we want to verify which actions have been executed for a particular process instance, or in general, we want to be able to monitor and analyze the efficiency of a particular process.

However, storing history information in the runtime database can result in the database rapidly increasing in size, not to mention the fact that monitoring and analysis queries might influence the performance of your runtime engine. This is why process execution history information can be stored separately.

This history log of execution information is created based on events that the process engine generates during execution. This is possible because the jBPM runtime engine provides a generic mechanism to listen to events. The necessary information can easily be extracted from these events and then persisted to a database. Filters can also be used to limit the scope of the logged information.

9.2.1. The jBPM Audit data model

The jbpm-audit module contains an event listener that stores process-related information in a database using JPA. The data model itself contains three entities, one for process instance information, one for node instance information, and one for (process) variable instance information.

The ProcessInstanceLog table contains the basic log information about a process instance.

Table 17. ProcessInstanceLog
Field Description Nullable

id

The primary key and id of the log entity

NOT NULL

duration

Actual duration of this process instance since its start date

end_date

When applicable, the end date of the process instance

externalId

Optional external identifier used to correlate to some elements - e.g. deployment id

user_identity

Optional identifier of the user who started the process instance

outcome

The outcome of the process instance, for instance error code in case of process instance was finished with error event

parentProcessInstanceId

The process instance id of the parent process instance if any

processid

The id of the process

processinstanceid

The process instance id

NOT NULL

processname

The name of the process

processversion

The version of the process

start_date

The start date of the process instance

status

The status of process instance that maps to process instance state

The NodeInstanceLog table contains more information about which nodes were actually executed inside each process instance. Whenever a node instance is entered from one of its incoming connections or is exited through one of its outgoing connections, that information is stored in this table.

Table 18. NodeInstanceLog
Field Description Nullable

id

The primary key and id of the log entity

NOT NULL

connection

Actual identifier of the sequence flow that led to this node instance

log_date

The date of the event

externalId

Optional external identifier used to correlate to some elements - e.g. deployment id

nodeid

The node id of the corresponding node in the process definition

nodeinstanceid

The node instance id

nodename

The name of the node

nodetype

The type of the node

processid

The id of the process that the process instance is executing

processinstanceid

The process instance id

NOT NULL

type

The type of the event (0 = enter, 1 = exit)

NOT NULL

workItemId

Optional - only for certain node types - The identifier of work item

The VariableInstanceLog table contains information about changes in variable instances. The default is to only generate log entries when (after) a variable changes. It’s also possible to log entries before the variable (value) changes.

Table 19. VariableInstanceLog
Field Description Nullable

id

The primary key and id of the log entity

NOT NULL

externalId

Optional external identifier used to correlate to some elements - e.g. deployment id

log_date

The date of the event

processid

The id of the process that the process instance is executing

processinstanceid

The process instance id

NOT NULL

oldvalue

The previous value of the variable at the time that the log is made

value

The value of the variable at the time that the log is made

variableid

The variable id in the process definition

variableinstanceid

The id of the variable instance

The AuditTaskImpl table contains information about tasks that can be used for queries.

Table 20. AuditTaskImpl
Field Description Nullable

id

The primary key and id of the task log entity

activationTime

Time when this task was activated

actualOwner

Actual owner assigned to this task - only set when task is claimed

createdBy

User who created this task

createdOn

Date when task was created

deploymentId

Deployment id this task is part of

description

Description of the task

dueDate

Due date set on this task

name

Name of the task

parentId

Parent task id

priority

Priority of the task

processId

Process definition id that this task belongs to

processInstanceId

Process instance id that this task is associated with

processSessionId

KieSession id used to create this task

status

Current status of the task

taskId

Identifier of task

workItemId

Identifier of work item assigned on process side to this task id

The BAMTaskSummary table that collects information about tasks that is used by BAM engine to build charts and dashboards.

Table 21. BAMTaskSummary
Field Description Nullable

id

The primary key and id of the log entity

NOT NULL

createdDate

Date whentask was created

duration

Duration since task was created

endDate

Date when task reached end state (complete, exit, fail, skip)

processinstanceid

The process instance id

startDate

Date when task was started

status

Current status of the task

taskId

Identifier of the task

taskName

Name of the task

userId

User id assigned to the task

The TaskVariableImpl table contains information about task variable instances.

Table 22. TaskVariableImpl
Field Description Nullable

id

The primary key and id of the log entity

NOT NULL

modificationDate

Date when the variable was modified last time

name

Name of the task

processid

The id of the process that the process instance is executing

processinstanceid

The process instance id

taskId

Identifier of the task

type

Type of the variable - either input or output of the task

value

Variable value

The TaskEvent table contains information about changes in task instances. Operations such as claim, start, stop etc are stored here to provide time line view of events that happened to given task.

Table 23. TaskEvent
Field Description Nullable

id

The primary key and id of the log entity

NOT NULL

logTime

LDate when this event was saved

message

Log event message

processinstanceid

The process instance id

taskId

Identifier of the task

type

Type of the event - corresponds to life cycle phases of the task

userId

User id assigned to the task

9.2.2. Storing Process Events in a Database

To log process history information in a database like this, you need to register the logger on your session like this:

EntityManagerFactory emf = this.createEntityManager();
StatefulKnowledgeSession ksession = this.buildKnowledgeSession();
AbstractAuditLogger auditLogger = AuditLoggerFactory.newJPAInstance(emf);
ksession.addProcessEventListener(auditLogger);

// invoke methods one your session here

To specify the database where the information should be stored, modify the file persistence.xml file to include the audit log classes as well (ProcessInstanceLog, NodeInstanceLog and VariableInstanceLog), as shown below.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>

<persistence
  version="2.0"
  xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd
  http://java.sun.com/xml/ns/persistence/orm http://java.sun.com/xml/ns/persistence/orm_2_0.xsd"
  xmlns="http://java.sun.com/xml/ns/persistence"
  xmlns:orm="http://java.sun.com/xml/ns/persistence/orm"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance>

  <persistence-unit name="org.jbpm.persistence.jpa" transaction-type="JTA">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <jta-data-source>jdbc/jbpm-ds</jta-data-source>
    <mapping-file>META-INF/JBPMorm.xml</mapping-file>
    <class>org.drools.persistence.info.SessionInfo</class>
    <class>org.jbpm.persistence.processinstance.ProcessInstanceInfo</class>
    <class>org.drools.persistence.info.WorkItemInfo</class>
    <class>org.jbpm.persistence.correlation.CorrelationKeyInfo</class>
    <class>org.jbpm.persistence.correlation.CorrelationPropertyInfo</class>
    <class>org.jbpm.runtime.manager.impl.jpa.ContextMappingInfo</class>

    <class>org.jbpm.process.audit.ProcessInstanceLog</class>
    <class>org.jbpm.process.audit.NodeInstanceLog</class>
    <class>org.jbpm.process.audit.VariableInstanceLog</class>

    <properties>
      <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/>
      <property name="hibernate.max_fetch_depth" value="3"/>
      <property name="hibernate.hbm2ddl.auto" value="update"/>
      <property name="hibernate.show_sql" value="true"/>
      <property name="hibernate.transaction.jta.platform"
      value="org.hibernate.service.jta.platform.internal.BitronixJtaPlatform"/>
    </properties>
  </persistence-unit>
</persistence>

All this information can easily be queried and used in a lot of different use cases, ranging from creating a history log for one specific process instance to analyzing the performance of all instances of a specific process.

This audit log should only be considered a default implementation. We don’t know what information you need to store for analysis afterwards, and for performance reasons it is recommended to only store the relevant data. Depending on your use cases, you might define your own data model for storing the information you need, and use the process event listeners to extract that information.

9.2.3. Storing Process Events in a JMS queue for further processing

Process events are stored in the database synchronously and within the same transaction as actual process instance execution. That obviously takes some time especially in highly loaded systems and might have some impact on the database when both history log and runtime data are kept in the same database. To provide an alternative option for storing process events, a JMS based logger has been provided. It can be configured to submit messages to JMS queue instead of directly persisting them in the database. It can be configured to be transactional as well to avoid issues with inconsistent data in case of process engine transaction is rolled back.

ConnectionFactory factory = ...;
Queue queue = ...;
StatefulKnowledgeSession ksession = ...;
Map<String, Object> jmsProps = new HashMap<String, Object>();
jmsProps.put("jbpm.audit.jms.transacted", true);
jmsProps.put("jbpm.audit.jms.connection.factory", factory);
jmsProps.put("jbpm.audit.jms.queue", queue);
AbstractAuditLogger auditLogger = AuditLoggerFactory.newInstance(Type.JMS, session, jmsProps);
ksession.addProcessEventListener(auditLogger);

// invoke methods one your session here

This is just one of possible ways to configure JMS audit logger, see javadocs for AuditLoggerFactory for more details.

9.2.4. Variables auditing

Process and task variables are stored in autdit tables by default although there are stored in simplest possible way - by creating string representation of the variable - variable.toString(). In many cases this is enough as even for custom classes used as variables users can implement custom toString() method that produces expected "view" of the variable.

Though this might not cover all needs, especially when there is a need for efficient queries by variables (both task and process). Let’s take as an example a Person object that has following structure:

public class Person implements Serializable{

    private static final long serialVersionUID = -5172443495317321032L;
    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Person [name=" + name + ", age=" + age + "]";
    }
}

while at first look this seems to be sufficient as the toString() methods provide human readable format it does not make it easy to be searched by. As searching through strings like "Person [name="john", age="34"] to find people with age 34 would make data base query very inefficient.

To solve the problem variable audit has been based on VariableIndexers that are responsible for extracting relevant parts of the variable that will be stored in audit log.

/**
 * Variable indexer that allows to transform variable instance into other representation (usually string)
 * to be able to use it for queries.
 *
 * @param <V> type of the object that will represent indexed variable
 */
public interface VariableIndexer<V> {

    /**
     * Tests if given variable shall be indexed by this indexer
     *
     * NOTE: only one indexer can be used for given variable
     *
     * @param variable variable to be indexed
     * @return true if variable should be indexed with this indexer
     */
    boolean accept(Object variable);

    /**
     * Performs index/transform operation of the variable. Result of this operation can be
     * either single value or list of values to support complex type separation.
     * For example when variable is of type Person that has name, address phone indexer could
     * build three entries out of it to represent individual fields:
     * person = person.name
     * address = person.address.street
     * phone = person.phone
     * that will allow more advanced queries to be used to find relevant entries.
     * @param name name of the variable
     * @param variable actual variable value
     * @return
     */
    List<V> index(String name, Object variable);
}

By default (indexer that takes the toString()) will prodce single audit entry for single variable, so it’s one to one relationship. But that’s not the only option: indexers (as can be seen in the interface) returns list of objects that are the outcome of single variable indexation.

To make our person queries more efficient we could build custom indexer that would take Person instance and index it into separate audit entries one representing name and the other representing age.

public class PersonTaskVariablesIndexer implements TaskVariableIndexer {

    @Override
    public boolean accept(Object variable) {
        if (variable instanceof Person) {
            return true;
        }
        return false;
    }

    @Override
    public List<TaskVariable> index(String name, Object variable) {

        Person person = (Person) variable;
        List<TaskVariable> indexed = new ArrayList<TaskVariable>();

        TaskVariableImpl personNameVar = new TaskVariableImpl();
        personNameVar.setName("person.name");
        personNameVar.setValue(person.getName());

        indexed.add(personNameVar);

        TaskVariableImpl personAgeVar = new TaskVariableImpl();
        personAgeVar.setName("person.age");
        personAgeVar.setValue(person.getAge()+"");

        indexed.add(personAgeVar);

        return indexed;
    }

}

That indexer will then be used to index Person class only and rest of variables will be indexed with default (toString()) indexer. Now when we want to find process instances or tasks that have person with age 34 we simple refer to it as

  • variable name: person.age

  • variable value: 34

There is not even need to use like based queries so data base can optimize the query and make it efficient even with big set of data.

Building and registering custom indexers

Indexers are supported for both process and task variables. though they are supported by different interfaces as they do produce different type of objects representing audit view of the variable. Following are the interfaces to be implemented to build custom indexers:

  • process variables: org.kie.internal.process.ProcessVariableIndexer

  • task variables: org.kie.internal.task.api.TaskVariableIndexer

Implementation is rather simple, just two methods to be implemented

  • accept - indicates what types are handled by given indexer. Note that only one indexer can index given variable, so the first that accepts it will perform the work

  • index - actually does the work to index variables depending on custom requirements

Once the implementation is done, it should be packaged as jar file and following file needs to be included:

  • for process variables: META-INF/services/org.kie.internal.process.ProcessVariableIndexer with list of FQCN that represent the process variable indexers (single class name per line in that file)

  • for task variables: META-INF/services/org.kie.internal.task.api.TaskVariableIndexer with list of FQCN that represent the task variable indexers (single class name per line in that file)

Indexers are discovered by ServiceLoader mechanism and thus the META-INF/services files need. All found indexers will be examined whenever process or task variable is about to be indexed.

Only the default (toString() based) indexer is not discovered but added explicitly as last indexer to allow custom ones to take the precedence over it.

9.3. Transactions

The jBPM engine supports JTA transactions. It also supports local transactions only when using Spring. It does not support pure local transactions at the moment. For more information about using Spring to set up persistence, please see the Spring chapter in the Drools integration guide.

Whenever you do not provide transaction boundaries inside your application, the engine will automatically execute each method invocation on the engine in a separate transaction. If this behavior is acceptable, you don’t need to do anything else. You can, however, also specify the transaction boundaries yourself. This allows you, for example, to combine multiple commands into one transaction.

You need to register a transaction manager at the environment before using user-defined transactions. The following sample code uses the Bitronix transaction manager. Next, we use the Java Transaction API (JTA) to specify transaction boundaries, as shown below:

// create the entity manager factory
EntityManagerFactory emf = EntityManagerFactoryManager.get().getOrCreate("org.jbpm.persistence.jpa");
TransactionManager tm = TransactionManagerServices.getTransactionManager();

// setup the runtime environment
RuntimeEnvironment environment = RuntimeEnvironmentBuilder.Factory.get()
.newDefaultBuilder()
.addAsset(ResourceFactory.newClassPathResource("MyProcessDefinition.bpmn2"), ResourceType.BPMN2)
    .addEnvironmentEntry(EnvironmentName.TRANSACTION_MANAGER, tm)
    .get();

// get the kie session
RuntimeManager manager = RuntimeManagerFactory.Factory.get().newPerRequestRuntimeManager(environment);
RuntimeEngine runtime = manager.getRuntimeEngine(ProcessInstanceIdContext.get());
KieSession ksession = runtime.getKieSession();

// start the transaction
UserTransaction ut = InitialContext.doLookup("java:comp/UserTransaction");
ut.begin();

// perform multiple commands inside one transaction
ksession.insert( new Person( "John Doe" ) );
ksession.startProcess("MyProcess");

// commit the transaction
ut.commit();

Note that, if you use Bitronix as the transaction manager, you should also add a simple jndi.properties file in you root classpath to register the Bitronix transaction manager in JNDI. If you are using the jbpm-test module, this is already included by default. If not, create a file named jndi.properties with the following content:

java.naming.factory.initial=bitronix.tm.jndi.BitronixInitialContextFactory

If you would like to use a different JTA transaction manager, you can change the persistence.xml file to use your own transaction manager. For example, when running inside JBoss Application Server v5.x or v7.x, you can use the JBoss transaction manager. You need to change the transaction manager property in persistence.xml to:

<property name="hibernate.transaction.jta.platform" value="org.hibernate.transaction.JBossTransactionManagerLookup" />

Using the (runtime manager) Singleton strategy with JTA transactions (UserTransaction or CMT) is not recommended because there is a race condition when using this. This race condition can result in an IllegalStateException with a message similar to "Process instance XXX is disconnected.".

This race conditation can be avoided by explicitly synchronizing around the KieSession instance when invoking the transaction in the user application code.

synchronized (ksession) {
    try {
        tx.begin();

        // use ksession
        // application logic

        tx.commit();
    } catch (Exception e) {
        //...
    }
}

9.3.1. Container managed transactions

Special consideration need to be taken when embedding jBPM inside an application that executes in Container Managed Transaction (CMT) mode, for instance EJB beans. This especially applies to application servers that does not allow accessing UserTransaction instance from JNDI when being part of container managed transaction, e.g. WebSphere Application Server. Since default implementation of transaction manager in jBPM is based on UserTransaction to get transaction status which is used to decide if transaction should be started or not, in environments that prevent accessing UserTrancation it won’t do its job. To secure proper execution in CMT environments a dedicated transaction manager implementation is provided:

org.jbpm.persistence.jta.ContainerManagedTransactionManager

This transaction manager expects that transaction is active and thus will always return ACTIVE when invoking getStatus method. Operations like begin, commit, rollback are no-op methods as transaction manager runs under managed transaction and can’t affect it.

To make sure that container is aware of any exceptions that happened during process instance execution, user needs to ensure that exceptions thrown by the engine are propagated up to the container to properly rollback transaction.

To configure this transaction manager following must be done:

  • Insert transaction manager and persistence context manager into environment prior to creating/loading session

    Environment env = EnvironmentFactory.newEnvironment();
    env.set(EnvironmentName.ENTITY_MANAGER_FACTORY, emf);
    env.set(EnvironmentName.TRANSACTION_MANAGER, new ContainerManagedTransactionManager());
    env.set(EnvironmentName.PERSISTENCE_CONTEXT_MANAGER, new JpaProcessPersistenceContextManager(env));
    env.set(EnvironmentName.TASK_PERSISTENCE_CONTEXT_MANAGER, new JPATaskPersistenceContextManager(env));
  • configure JPA provider (example hibernate and WebSphere)

    <property name="hibernate.transaction.factory_class" value="org.hibernate.transaction.CMTTransactionFactory"/>
    <property name="hibernate.transaction.jta.platform" value="org.hibernate.service.jta.platform.internal.WebSphereJtaPlatform"/>

With following configuration jBPM should run properly in CMT environment.

9.3.1.1. CMT dispose ksession command

Usually when running within container managed transaction disposing ksession directly will cause exceptions on transaction completion as there are some transaction synchronization registered by jBPM to clean up the state after invocation is finished.

To overcome this problem specialized command has been provided org.jbpm.persistence.jta.ContainerManagedTransactionDisposeCommand which allows to simply execute this command instead of regular ksession.dispose which will ensure that ksession will be disposed at the transaction completion.

9.4. Configuration

By default, the engine does not save runtime data persistently. This means you can use the engine completely without persistence (so not even requiring an in memory database) if necessary, for example for performance reasons, or when you would like to manage persistence yourself. It is, however, possible to configure the engine to do use persistence by configuring it to do so. This usually requires adding the necessary dependencies, configuring a datasource and creating the engine with persistence configured.

9.4.1. Adding dependencies

You need to make sure the necessary dependencies are available in the classpath of your application if you want to user persistence. By default, persistence is based on the Java Persistence API (JPA) and can thus work with several persistence mechanisms. We are using Hibernate by default.

If you’re using the Eclipse IDE and the jBPM Eclipse plugin, you should make sure the necessary JARs are added to your jBPM runtime directory. You don’t really need to do anything (as the necessary dependencies should already be there) if you are using the jBPM runtime that is configured by default when using the jBPM installer, or if you downloaded and unzipped the jBPM runtime artifact (from the downloads) and pointed the jBPM plugin to that directory.

If you would like to manually add the necessary dependencies to your project, first of all, you need the JAR file jbpm-persistence-jpa.jar , as that contains code for saving the runtime state whenever necessary. Next, you also need various other dependencies, depending on the persistence solution and database you are using. For the default combination with Hibernate as the JPA persistence provider and using an H2 in-memory database and Bitronix for JTA-based transaction management, the following list of additional dependencies is needed:

  • jbpm-persistence-jpa (org.jbpm)

  • drools-persistence-jpa (org.drools)

  • persistence-api (javax.persistence)

  • hibernate-entitymanager (org.hibernate)

  • hibernate-annotations (org.hibernate)

  • hibernate-commons-annotations (org.hibernate)

  • hibernate-core (org.hibernate)

  • commons-collections (commons-collections)

  • dom4j (dom4j)

  • jta (javax.transaction)

  • btm (org.codehaus.btm)

  • javassist (javassist)

  • slf4j-api (org.slf4j)

  • slf4j-jdk14 (org.slf4j)

  • h2 (com.h2database)

  • jbpm-test (org.jbpm) for testing only, do not include it in the actual application

9.4.2. Manually configuring the engine to use persistence

You can use the JPAKnowledgeService to create your knowledge session. This is slightly more complex, but gives you full access to the underlying configurations. You can create a new knowledge session using JPAKnowledgeService based on a knowledge base, a knowledge session configuration (if necessary) and an environment. The environment needs to contain a reference to your Entity Manager Factory. For example:

// create the entity manager factory and register it in the environment
EntityManagerFactory emf =
    Persistence.createEntityManagerFactory( "org.jbpm.persistence.jpa" );
Environment env = KnowledgeBaseFactory.newEnvironment();
env.set( EnvironmentName.ENTITY_MANAGER_FACTORY, emf );

// create a new knowledge session that uses JPA to store the runtime state
StatefulKnowledgeSession ksession = JPAKnowledgeService.newStatefulKnowledgeSession( kbase, null, env );
int sessionId = ksession.getId();

// invoke methods on your method here
ksession.startProcess( "MyProcess" );
ksession.dispose();

You can also use the JPAKnowledgeService to recreate a session based on a specific session id:

// recreate the session from database using the sessionId
ksession = JPAKnowledgeService.loadStatefulKnowledgeSession(sessionId, kbase, null, env );

Note that we only save the minimal state that is needed to continue execution of the process instance at some later point. This means, for example, that it does not contain information about already executed nodes if that information is no longer relevant, or that process instances that have been completed or aborted are removed from the database. If you want to search for history-related information, you should use the history log, as explained later.

You need to add a persistence configuration to your classpath to configure JPA to use Hibernate and the H2 database (or your own preference), called persistence.xml in the META-INF directory, as shown below. For more details on how to change this for your own configuration, we refer to the JPA and Hibernate documentation for more information.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<persistence
      version="2.0"
      xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd
      http://java.sun.com/xml/ns/persistence/orm http://java.sun.com/xml/ns/persistence/orm_2_0.xsd"
      xmlns="http://java.sun.com/xml/ns/persistence"
      xmlns:orm="http://java.sun.com/xml/ns/persistence/orm"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

  <persistence-unit name="org.jbpm.persistence.jpa" transaction-type="JTA">
    <provider>org.hibernate.ejb.HibernatePersistence</provider>
    <jta-data-source>jdbc/jbpm-ds</jta-data-source>
    <mapping-file>META-INF/JBPMorm.xml</mapping-file>
    <class>org.drools.persistence.info.SessionInfo</class>
    <class>org.jbpm.persistence.processinstance.ProcessInstanceInfo</class>
    <class>org.drools.persistence.info.WorkItemInfo</class>
    <class>org.jbpm.persistence.correlation.CorrelationKeyInfo</class>
    <class>org.jbpm.persistence.correlation.CorrelationPropertyInfo</class>
    <class>org.jbpm.runtime.manager.impl.jpa.ContextMappingInfo</class>

    <properties>
      <property name="hibernate.dialect" value="org.hibernate.dialect.H2Dialect"/>
      <property name="hibernate.max_fetch_depth" value="3"/>
      <property name="hibernate.hbm2ddl.auto" value="update"/>
      <property name="hibernate.show_sql" value="true"/>
      <property name="hibernate.transaction.jta.platform"
                value="org.hibernate.service.jta.platform.internal.BitronixJtaPlatform"/>
    </properties>
  </persistence-unit>
</persistence>

This configuration file refers to a data source called "jdbc/jbpm-ds". If you run your application in an application server (like for example JBoss AS), these containers typically allow you to easily set up data sources using some configuration (like for example dropping a datasource configuration file in the deploy directory). Please refer to your application server documentation to know how to do this.

For example, if you’re deploying to JBoss Application Server v5.x, you can create a datasource by dropping a configuration file in the deploy directory, for example:

<?xml version="1.0" encoding="UTF-8"?>
<datasources>
  <local-tx-datasource>
    <jndi-name>jdbc/jbpm-ds</jndi-name>
    <connection-url>jdbc:h2:tcp://localhost/~/test</connection-url>
    <driver-class>org.h2.jdbcx.JdbcDataSource</driver-class>
    <user-name>sa</user-name>
    <password></password>
  </local-tx-datasource>
</datasources>

If you are however executing in a simple Java environment, you can use the JBPMHelper class to do this for you (see below for tests only) or the following code fragment could be used to set up a data source (where we are using the H2 in-memory database in combination with Bitronix in this case).

PoolingDataSource ds = new PoolingDataSource();
ds.setUniqueName("jdbc/jbpm-ds");
ds.setClassName("bitronix.tm.resource.jdbc.lrc.LrcXADataSource");
ds.setMaxPoolSize(3);
ds.setAllowLocalTransactions(true);
ds.getDriverProperties().put("user", "sa");
ds.getDriverProperties().put("password", "sasa");
ds.getDriverProperties().put("URL", "jdbc:h2:mem:jbpm-db");
ds.getDriverProperties().put("driverClassName", "org.h2.Driver");
ds.init();

9.4.3. Configuring the engine to use persistence using JBPMHelper - for tests only

You need to configure the jBPM engine to use persistence, usually simply by using the appropriate constructor when creating your session. There are various ways to create a session (as we have tried to make this as easy as possible for you and have several utility classes for you, depending for example if you are trying to write a process JUnit test).

The easiest way to do this is to use the jbpm-test module that allows you to easily create and test your processes. The JBPMHelper class has a method to create a session, and uses a configuration file to configure this session, like whether you want to use persistence, the datasource to use, etc. The helper class will then do all the setup and configuration for you.

To configure persistence, create a jBPM.properties file and configure the following properties (note that the example below are the default properties, using an H2 in-memory database with persistence enabled, if you are fine with all of these properties, you don’t need to add new properties file, as it will then use these properties by default):

# for creating a datasource
persistence.datasource.name=jdbc/jbpm-ds
persistence.datasource.user=sa
persistence.datasource.password=
persistence.datasource.url=jdbc:h2:tcp://localhost/~/jbpm-db
persistence.datasource.driverClassName=org.h2.Driver

# for configuring persistence of the session
persistence.enabled=true
persistence.persistenceunit.name=org.jbpm.persistence.jpa
persistence.persistenceunit.dialect=org.hibernate.dialect.H2Dialect

# for configuring the human task service
taskservice.enabled=true
taskservice.datasource.name=org.jbpm.task
taskservice.usergroupcallback=org.jbpm.services.task.identity.JBossUserGroupCallbackImpl
taskservice.usergroupmapping=classpath:/usergroups.properties

If you want to use persistence, you must make sure that the datasource (that you specified in the jBPM.properties file) is initialized correctly. This means that the database itself must be up and running, and the datasource should be registered using the correct name. If you would like to use an H2 in-memory database (which is usually very easy to do some testing), you can use the JBPMHelper class to start up this database, using:

JBPMHelper.startH2Server();

To register the datasource (this is something you always need to do, even if you’re not using H2 as your database, check below for more options on how to configure your datasource), use:

JBPMHelper.setupDataSource();

Next, you can use the JBPMHelper class to create your session (after creating your knowledge base, which is identical to the case when you are not using persistence):

StatefulKnowledgeSession ksession = JBPMHelper.newStatefulKnowledgeSession(kbase);

Once you have done that, you can just call methods on this ksession (like startProcess) and the engine will persist all runtime state in the created datasource.

You can also use the JBPMHelper class to recreate your session (by restoring its state from the database, by passing in the session id (that you can retrieve using ksession.getId())):

StatefulKnowledgeSession ksession = JBPMHelper.loadStatefulKnowledgeSession(kbase, sessionId);

Workbench

How to use the web-based Workbench

10. Workbench (General)

10.1. Installation

10.1.1. War installation

Use the war from the workbench distribution zip that corresponds to your application server. The differences between these war files are mainly superficial. For example, some JARs might be excluded if the application server already supplies them.

  • eap7: tailored for Red Hat JBoss Enterprise Application Platform 7

  • tomcat8: tailored for Apache Tomcat 8

    Apache Tomcat requires additional configuration to correctly install the Workbench. Please consult the README.md in the war for the most up to date procedure.

  • wildfly10: tailored for Red Hat JBoss Wildfly 10

10.1.2. Workbench data

The workbench stores its data, by default in the directory $WORKING_DIRECTORY/.niogit, for example wildfly-10.0.0.Final/bin/.niogit, but it can be overridden with the system property-Dorg.uberfire.nio.git.dir.

In production, make sure to back up the workbench data directory.

10.1.3. System properties

Here’s a list of all system properties:

  • org.uberfire.nio.git.dir: Location of the directory .niogit. Default: working directory

  • org.uberfire.nio.git.dirname: Name of the git directory. Default: .niogit

  • org.uberfire.nio.git.daemon.enabled: Enables/disables git daemon. Default: true

  • org.uberfire.nio.git.daemon.host: If git daemon enabled, uses this property as local host identifier. Default: localhost

  • org.uberfire.nio.git.daemon.port: If git daemon enabled, uses this property as port number. Default: 9418

  • org.uberfire.nio.git.ssh.enabled: Enables/disables ssh daemon. Default: true

  • org.uberfire.nio.git.ssh.host: If ssh daemon enabled, uses this property as local host identifier. Default: localhost

  • org.uberfire.nio.git.ssh.port: If ssh daemon enabled, uses this property as port number. Default: 8001

  • org.uberfire.nio.git.ssh.cert.dir: Location of the directory .security where local certificates will be stored. Default: working directory

  • org.uberfire.nio.git.ssh.passphrase: Passphrase to access your Operating Systems public keystore when cloning git repositories with scp style URLs; e.g. git@github.com:user/repository.git.

  • org.uberfire.nio.git.ssh.algorithm: Algorithm used by SSH. Default: DSA

    If you plan to use RSA or any algorithm other than DSA, make sure you setup properly your Application Server to use Bouncy Castle JCE library.

  • org.uberfire.metadata.index.dir: Place where Lucene .index folder will be stored. Default: working directory

  • org.uberfire.cluster.id: Name of the helix cluster, for example: kie-cluster

  • org.uberfire.cluster.zk: Connection string to zookeeper. This is of the form host1:port1,host2:port2,host3:port3, for example: localhost:2188

  • org.uberfire.cluster.local.id: Unique id of the helix cluster node, note that ‘`:`’ is replaced with ‘`\_`’, for example: node1_12345

  • org.uberfire.cluster.vfs.lock: Name of the resource defined on helix cluster, for example: kie-vfs

  • org.uberfire.cluster.autostart: Delays VFS clustering until the application is fully initialized to avoid conflicts when all cluster members create local clones. Default: false

  • org.uberfire.sys.repo.monitor.disabled: Disable configuration monitor (do not disable unless you know what you’re doing). Default: false

  • org.uberfire.secure.key: Secret password used by password encryption. Default: org.uberfire.admin

  • org.uberfire.secure.alg: Crypto algorithm used by password encryption. Default: PBEWithMD5AndDES

  • org.uberfire.domain: security-domain name used by uberfire. Default: ApplicationRealm

  • org.guvnor.m2repo.dir: Place where Maven repository folder will be stored. Default: working-directory/repositories/kie

  • org.guvnor.project.gav.check.disabled: Disable GAV checks. Default: false

  • org.kie.example.repositories: Folder from where demo repositories will be cloned. The demo repositories need to have been obtained and placed in this folder. Demo repositories can be obtained from the kie-wb-6.2.0-SNAPSHOT-example-repositories.zip artifact. This System Property takes precedence over org.kie.demo and org.kie.example. Default: Not used.

  • org.kie.demo: Enables external clone of a demo application from GitHub. This System Property takes precedence over org.kie.example. Default: true

  • org.kie.example: Enables example structure composed by Repository, Organization Unit and Project. Default: false

  • org.kie.build.disable-project-explorer: Disable automatic build of selected Project in Project Explorer. Default: false

  • org.kie.verification.disable-dtable-realtime-verification: Disables the realtime validation and verification of decision tables. Default: false

To change one of these system properties in a WildFly or JBoss EAP cluster:

  1. Edit the file $JBOSS_HOME/domain/configuration/host.xml.

  2. Locate the XML elements server that belong to the main-server-group and add a system property, for example:

    <system-properties>
      <property name="org.uberfire.nio.git.dir" value="..." boot-time="false"/>
      ...
    </system-properties>

10.1.4. Trouble shooting

10.1.4.1. Loading.. does not disappear and Workbench fails to show

There have been reports that Firewalls in between the server and the browser can interfere with Server Sent Events (SSE) used by the Workbench.

The issue results in the "Loading…​" spinner remaining visible and the Workbench failing to materialize.

The workaround is to disable the Workbench’s use of Server Sent Events by adding file /WEB-INF/classes/ErraiService.properties to the exploded WAR containing the value errai.bus.enable_sse_support=false. Re-package the WAR and re-deploy.

Some Users have also reported disabling Server Sent Events does not resolve the issue. The solution found to work is to configure the JVM to use a different Entropy Gathering Device on Linux for SecureRandom. This can be configured by setting System Property java.security.egd to file:/dev/./urandom. See this Stack Overflow post for details.

Please note however this affects the JVM’s random number generation and may present other challenges where strong cryptography is required. Configure with caution.

10.2. Quick Start

These steps help you get started with minimum of effort.

They should not be a substitute for reading the documentation in full.

10.2.1. Importing examples

Import Examples - Quick install examples

If the Workbench is empty the Project Authoring shows a quick import page. Clicking any of the example buttons below will install an example for you.

QuickStart example1

If the Workbench already contains Projects the examples can be imported with the "Import Example" button.

QuickStart import with pre existing projects

10.2.2. Add Project

Alternatively, to importing an example, a new empty project can be created from the Project Authoring.

QuickStart create project
Figure 25. New Project button

Select "Quick setup" and give the Project a name and optional description.

QuickStart new project wizard
Figure 26. Giving Project a name

10.2.3. Define Data Model

After a Project has been created you need to define Types to be used by your rules.

Select "Data Object" from the "Create New Asset" menu.

You can also use types contained in existing JARs.

Please consult the full documentation for details.

QuickStart create a data model
Figure 27. Creating "Data Object"

Set the name and select a package for the new type.

QuickStart create data object popup
Figure 28. Creating a new type

Click "+ add field" button and set a field name and type and click on "Create" to create a field for the type.

QuickStart create field
Figure 29. Click "Create" and add the field

Click "Save" to update the model.

QuickStart confirm save
Figure 30. Clicking "Save"

10.2.4. Define Rule

Select "DRL file" (for example) from the "Create New Asset" menu.

QuickStart create drl file
Figure 31. Selecting "DRL file" from the "Create New Asset" menu

Enter a file name for the new rule.

Make sure you select the same package as the rule had. It is possible to have rules and data models in different packages, but let’s keep things simple for demo purposes.

QuickStart new rule popup
Figure 32. Entering file name for rule

Enter a definition for the rule.

The definition process differs from asset type to asset type.

The full documentation has details about the different editors.

QuickStart writing a rule
Figure 33. Defining a rule

Once the rule has been defined it will need to be saved in the same way we saved the model.

10.2.5. Build and Deploy

Once rules have been defined within a project; the project can be built and deployed to the Workbench’s Maven Artifact Repository.

To build a project select the "Build & Deploy" from the Project Authoring.

QuickStart build and deploy
Figure 34. Building a project

Click "Build & Deploy" to build the project and deploy it to the Workbench’s Maven Artifact Repository.

When you select Build & Deploy the workbench will deploy to any repositories defined in the Dependency Management section of the pom in your workbench project. You can edit the pom.xml file associated with your workbench project under the Repository View of the project explorer. Details on dependency management in maven can be found here : http://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html

If there are errors during the build process they will be reported in the "Messages" panel.

Now the project has been built and deployed; it can be referenced from your own projects as any other Maven Artifact.

The full documentation contains details about integrating projects with your own applications.

10.3. Administration

10.3.1. Administration overview

A workbench is structured with Organization Units, VFS repositories and projects:

workbenchStructureOverview

10.3.2. Organizational unit

Organization units are useful to model departments and divisions.

An organization unit can hold multiple repositories.

organizationalUnitManager

10.3.3. Repositories

Repositories are the place where assets are stored and each repository is organized by projects and belongs to a single organization unit.

Repositories are in fact a Virtual File System based storage, that by default uses GIT as backend. Such setup allows workbench to work with multiple backends and, in the same time, take full advantage of backend specifics features like in GIT case versioning, branching and even external access.

repositoriesEditor

A new repository can be created from scratch or cloned from an existing repository.

One of the biggest advantage of using GIT as backend is the ability to clone a repository from external and use your preferred tools to edit and build your assets.

Never clone your repositories directly from .niogit directory. Use always the available protocol(s) displayed in repositories editor.

10.3.3.1. Repository Editor

One additional advantage to use GIT as backend is the possibility to revert your repository to a previous state. You can do it directly from the repository editor by browsing its commit history and clicking the Revert button.

repositoryEditor

10.4. Configuration

10.4.1. Basic user management

The workbench authenticates its users against the application server’s authentication and authorization (JAAS).

On JBoss EAP and WildFly, add a user with the script $JBOSS_HOME/bin/add-user.sh (or .bat):

$ ./add-user.sh
// Type: Application User
// Realm: empty (defaults to ApplicationRealm)
// Role: admin

There is no need to restart the application server.

10.4.2. Roles

The Workbench uses the following roles:

  • admin

  • analyst

  • developer

  • manager

  • user

10.4.2.1. Admin

Administrates the BPMS system.

  • Manages users

  • Manages VFS Repositories

  • Has full access to make any changes necessary

10.4.2.2. Developer

Developer can do almost everything admin can do, except clone repositories.

  • Manages rules, models, process flows, forms and dashboards

  • Manages the asset repository

  • Can create, build and deploy projects

  • Can use the JBDS connection to view processes

10.4.2.3. Analyst

Analyst is a weaker version of developer and does not have access to the asset repository or the ability to deploy projects.

10.4.2.4. Business user

Daily user of the system to take actions on business tasks that are required for the processes to continue forward. Works primarily with the task lists.

  • Does process management

  • Handles tasks and dashboards

10.4.2.5. Manager/Viewer-only User

Viewer of the system that is interested in statistics around the business processes and their performance, business indicators, and other reporting of the system and people who interact with the system.

  • Only has access to dashboards

10.5. Introduction

10.5.1. Log in and log out

Create a user with the role admin and log in with those credentials.

After successfully logging in, the account username is displayed at the top right. Click on it to review the roles of the current account.

10.5.2. Home screen

After logging in, the home screen shows. The actual content of the home screen depends on the workbench variant (Drools, jBPM, …​).

home

10.5.3. Workbench concepts

The Workbench is comprised of different logical entities:

  • Part

    A Part is a screen or editor with which the user can interact to perform operations.

    Example Parts are "Project Explorer", "Project Editor", "Guided Rule Editor" etc.

  • Perspective

    A perspective is a logical grouping of related Panels and Parts.

    The user can switch between perspectives by clicking on one of the top-level menu items; such as "Home", "Authoring", "Deploy" etc.

10.6. Changing the layout

10.6.1. Resizing

Move the mouse pointer over the panel splitter (a grey horizontal or vertical line in between panels).

The cursor will by changing indicate it is positioned correctly over the splitter. Press and hold the left mouse button and drag the splitter to the required position; then release the left mouse button.

10.7. Authoring (General)

10.7.1. Artifact Repository

Projects often need external artifacts in their classpath in order to build, for example a domain model JARs. The artifact repository holds those artifacts.

The Artifact Repository is a full blown Maven repository. It follows the semantics of a Maven remote repository: all snapshots are timestamped. But it is often stored on the local hard drive.

By default the artifact repository is stored under $WORKING_DIRECTORY/repositories/kie, but it can be overridden with the system property-Dorg.guvnor.m2repo.dir. There is only 1 Maven repository per installation.

The Artifact Repository screen shows a list of the artifacts in the Maven repository:

mavenRepositoryExplorer

To add a new artifact to that Maven repository, either:

  • Use the upload button and select a JAR. If the JAR contains a POM file under META-INF/maven (which every JAR build by Maven has), no further information is needed. Otherwise, a groupId, artifactId and version need be given too.

mavenRepositoryUpload
  • Using Maven, mvn deploy to that Maven repository. Refresh the list to make it show up.

This remote Maven repository is relatively simple. It does not support proxying, mirroring, …​ like Nexus or Archiva.

10.7.2. Asset Editor

The Asset Editor is the principle component of the workbench User-Interface. It consists of two main views Editor and Overview.

  • The views

    AssetEditor edit
    Figure 35. The Asset Editor - Editor tab
    • A : The editing area - exactly what form the editor takes depends on the Asset type. An asset can only be edited by one user at a time to avoid conflicts. When a user begins to edit an asset, a lock will automatically be acquired. This is indicated by a lock symbol appearing on the asset title bar as well as in the project explorer view (see Project Explorer for details). If a user starts editing an already locked asset a pop-up notification will appear to inform the user that the asset can’t currently be edited, as it is being worked on by another user. Changes will be prevented until the editing user saves or closes the asset, or logs out of the workbench. Session timeouts will also cause locks to be released. Every user further has the option to force a lock release, if required (see the Metadata section below).

    • B : This menu bar contains various actions for the Asset; such as Save, Rename, Copy etc. Note that saving, renaming and deleting are deactivated if the asset is locked by a different user.

    • C : Different views for asset content or asset information.

      • Editor shows the main editor for the asset

      • Overview contains the metadata and conversation views for this editor. Explained in more detail below.

      • Source shows the asset in plain DRL. Note: This tab is only visible if the asset content can be generated into DRL.

      • Data Objects contains the model available for authoring. By default only Data Objects that reside within the same package as the asset are available for authoring. Data Objects outside of this package can be imported to become available for authoring the asset.

    AssetEditor dataobjects
    Figure 36. The Asset Editor - Data Objects tab
  • Overview

    • A : General information about the asset and the asset’s description.

      "Type:" The format name of the type of Asset.

      "Description:" Description for the asset.

      "Used in projects:" Names the projects where this rule is used.

      "Last Modified:" Who made the last change and when.

      "Created on:" Who created the asset and when.

    • B : Version history for the asset. Selecting a version loads the selected version into this editor.

    • C : Meta data (from the "Dublin Core" standard)

    • D : Comments regarding the development of the Asset can be recorded here.

    .The Asset Editor - Overview tab image::Workbench/Authoring/AssetEditor/Overview.png[align="center"]

  • Metadata

    • A : Meta data:-

      "Tags:" A tagging system for grouping the assets.

      "Note:" A comment made when the Asset was last updated (i.e. why a change was made)

      "URI:" URI to the asset inside the Git repository.

      "Subject/Type/External link/Source" : Other miscellaneous meta data for the Asset.

      "Lock status" : Shows the lock status of the asset and, if locked, allows to force unlocking the asset.

    .The Metadata tab image::Workbench/Authoring/AssetEditor/Metadata.png[align="center"]

  • Locking

    The Workbench supports pessimistic locking of assets. When one User starts editing an asset it is locked to change by other Users. The lock is held until a period of inactivity lapses, the Editor is closed or the application stopped and restarted. Locks can also be forcibly removed on the MetaData section of the Overview tab.

    A "padlock" icon is shown in the Editor’s title bar and beside the asset in the Project Explorer when an asset is locked.

    AssetEditor locked
    Figure 37. The Asset Editor - Locked assets cannot be edited by other users

10.7.3. Tags Editor

Tags allow assets to be labelled with any number of tags that you define. These tags can be used to filter assets on the Project Explorer enabling "Tag filtering".

10.7.3.1. Creating Tags

To create tags you simply have to write them on the Tags input and press the "Add new Tag/s" button. The Tag Editor allows creating tags one by one or writing more than one separated with a white space.

CreatingTags
Figure 38. Creating Tags

Once you created new Tags they will appear over the Editor allowing you to remove them by pressing on them if you want.

ExistingTags
Figure 39. Existing Tags

10.7.4. Project Explorer

The Project Explorer provides the ability to browse files in side the current Repository.

10.7.4.1. Initial view

If a file is currently being edited by another user, a lock symbol will be displayed in front of the file name. The symbol is blue in case the lock is owned by the currently authenticated user, otherwise black. Moving the mouse pointer over the lock symbol will display a tooltip providing the name of the user who is currently editing the file (and therefore owning the lock). To learn more about locking see Asset Editor for details.

ProjectExplorer Project Expanded
Figure 40. Expanded asset group
10.7.4.2. Different views

Project Explorer supports multiple views.

  • Project View

    A simplified view of the underlying project structure. Certain system files are hidden from view.

  • Repository View

    A complete view of the underlying project structure including all files; either user-defined or system generated.

Views can be selected by clicking on the icon within the Project Explorer, as shown below.

Both Project and Repository Views can be further refined by selecting either "Show as Folders" or "Show as Links".

ProjectExplorer Switching View
Figure 41. Switching view
Repository View examples
ProjectExplorer Repository Folders
Figure 42. Repository View - Folders
ProjectExplorer Repository Links
Figure 43. Repository View - Links
10.7.4.3. Download Project or Repository

Download Download and Download Repository make it possible to download the project or repository as a zip file.

ProjectExplorer Downloads
Figure 44. Repository and Project Downloads
10.7.4.4. Filtering by Tag

To make easy view the elements on packages that contain a lot of assets, is possible to enabling the Tag filter, whichs allows you to filter the assets by their tags.

To see how to add tags to an asset look at: Tags Editor

ProjectExplorer Tag Filter Enable
Figure 45. Enabling Filter by Tag
ProjectExplorer Tag Filter Show
Figure 46. Filter by Tag
ProjectExplorer Tag Filter Working
Figure 47. Filtering by Tag
10.7.4.5. Copy, Rename, Delete and Download Actions

Copy, rename and delete actions are available on Links mode, for packages in of Project View and for files and directories in Repository View. Download action is available for directories. Download option downloads the selected the selected directory as a zip file.

  • A : Copy

  • B : Rename

  • C : Delete

  • D : Download

ProjectExplorer Project Links Copy Rename Delete
Figure 48. Project View - Package actions

Workbench roadmap includes a refactoring and an impact analyses tools, but currenctly doesn’t have it. Until both tools are provided make sure that your changes (copy/rename/delete) on packages, files or directories doesn’t have a major impact on your project.

In cases that your change had an unexcepcted impact, Workbench allows you to restore your repository using the Repository editor.

Files locked by other users as well as directories that contain such files cannot be renamed or deleted until the corresponding locks are released. If that is the case the rename and delete symbols will be deactivated. To learn more about locking see Asset Editor for details.

ProjectExplorer Delete NotAllowed

10.7.5. Project Editor

The Project Editor screen can be accessed from Project Explorer. Project Editor shows the settings for the currently active project.

Unlike most of the workbench editors, project editor edits more than one file. Showing everything that is needed for configuring the KIE project in one place.

project editor menu
Figure 49. Project Screen and the different views
10.7.5.1. Build & Deploy

Build & Depoy builds the current project and deploys the KJAR into the workbench internal Maven repository.

10.7.5.2. Project Settings

Project Settings edits the pom.xml file used by Maven.

Project General Settings

General settings provide tools for project name and GAV-data (Group, Artifact, Version). GAV values are used as identifiers to differentiate projects and versions of the same project.

general settings
Figure 50. Project Settings
Dependencies

The project may have any number of either internal or external dependencies. Dependency is a project that has been built and deployed to a Maven repository. Internal dependencies are projects build and deployed in the same workbench as the project. External dependencies are retrieved from repositories outside of the current workbench. Each dependency uses the GAV-values to specify the project name and version that is used by the project.

dependencies
Figure 51. Dependencies
Package Name White List

Classes and declared types in white listed packages show up as Data Objects that can be imported in assets. The full list is stored in package-name-white-list file that is stored in each project root.

Package white list has three modes:

  • All packages included: Every package defined in this jar is white listed.

  • Packages not included: None of the packages listed in this jar are white listed.

  • Some packages included: Only part of the packages in the jar are white listed.

Metadata

Metadata for the pom.xml file.

10.7.5.3. Knowledge Base Settings

Knowledge Base Settings edits the kmodule.xml file used by Drools.

kmodule
Figure 52. Knowledge Base Settings

For more information about the Knowledge Base properties, check the Drools Expert documentation for kmodule.xml.

Knowledge bases and sessions

Knowledge bases and sessions lists the knowledge bases and the knowledge sessions specified for the project.

Knowledge base list

Lists all the knowledge bases by name. Only one knowledge base can be set as default.

Knowledge base properties

Knowledge base can include other knowledge bases. The models, rules and any other content in the included knowledge base will be visible and usable by the currently selected knowledge base.

Rules and models are stored in packages. The packages property specifies what packages are included into this knowledge base.

Equals behavior is explained in the Drools Expert part of the documentation.

Event processing mode is explained in the Drools Fusion part of the documentation.

Knowledge sessions

The table lists all the knowledge sessions in the selected knowledge base. There can be only one default of each type. The types are stateless and stateful. Clicking the pen-icon opens a popup that shows more properties for the knowledge session.

Metadata

Metadata for the kmodule.xml

10.7.5.4. Imports

Settings edits the project.imports file used by the workbench editors.

ExternalDataObjects
Figure 53. Imports
External Data Objects

Data Objects provided by the Java Runtime environment may need to be registered to be available to rule authoring where such Data Objects are not implicitly available as part of an existing Data Object defined within the Workbench or a Project dependency. For example an Author may want to define a rule that checks for java.util.ArrayList in Working Memory. If a domain Data Object has a field of type java.util.ArrayList there is no need create a registraton.

Metadata

Metadata for the project.imports file.

10.7.5.5. Duplicate GAV detection

When performing any of the following operations a check is now made against all Maven Repositories, resolved for the Project, for whether the Project’s GroupId, ArtifactId and Version pre-exist. If a clash is found the operation is prevented; although this can be overridden by Users with the admin role.

The feature can be disabled by setting the System Property org.guvnor.project.gav.check.disabled to true.

Resolved repositories are those discovered in:-

  • The Project’s POM<repositories> section (or any parent POM).

  • The Project’s POM<distributionManagement> section.

  • Maven’s global settings.xml configuration file.

Affected operations:-

  • Creation of new Managed Repositories.

  • Saving a Project defintion with the Project Editor.

  • Adding new Modules to a Managed Multi-Module Repository.

  • Saving the pom.xml file.

  • Build & installing a Project with the Project Editor.

  • Build & deploying a Project with the Project Editor.

  • Asset Management operations building, installing or deloying Projects.

  • REST operations creating, installing or deploying Projects.

Users with the Admin role can override the list of Repositories checked using the "Repositories" settings in the Project Editor.

MavenRepositories1
Figure 54. Project Editor - Viewing resolved Repositories
MavenRepositories2
Figure 55. Project Editor - The list of resolved Repositories
MavenRepositories3
Figure 56. Duplicate GAV detected

10.7.6. Validation

The Workbench provides a common and consistent service for users to understand whether files authored within the environment are valid.

10.7.6.1. Problem Panel

The Problems Panel shows real-time validation results of assets within a Project.

When a Project is selected from the Project Explorer the Problems Panel will refresh with validation results of the chosen Project.

When files are created, saved or deleted the Problems Panel content will update to show either new validation errors, or remove existing if a file was deleted.

workbench problems panel
Figure 57. The Problems Panel
10.7.6.2. On demand validation

It is not always desirable to save a file in order to determine whether it is in a valid state.

All of the file editors provide the ability to validate the content before it is saved.

Clicking on the 'Validate' button shows validation errors, if any.

workbench validation

10.7.7. Data Modeller

10.7.7.1. First steps to create a data model

By default, a data model is always constrained to the context of a project. For the purpose of this tutorial, we will assume that a correctly configured project already exists and the authoring perspective is open.

To start the creation of a data model inside a project, take the following steps:

  1. From the home panel, select the authoring perspective and select the given project.

    authoring
    Figure 58. Go to authoring perspective and select a project
  2. Open the Data Modeller tool by clicking on a Data Object file, or using the "Create New Asset → Data Object" menu option.

    open data model
    Figure 59. Click on a Data Object

This will start up the Data Modeller tool, which has the following general aspect:

overview
Figure 60. Data modeller overview

The "Editor" tab is divided into the following sections:

  • The new field section is dedicated to the creation of new fields, and is opened when the "add field" button is pressed.

    create new field
    Figure 61. New field creation
  • The Data Object’s "field browser" section displays a list with the data object fields.

    data object field browser
    Figure 62. The Data Object’s field browser
  • The "Data Object / Field general properties" section. This is the rightmost section of the Data Modeller editor and visualizes the "Data Object" or "Field" general properties, depending on user selection.

    Data Object general properties can be selected by clicking on the Data Object Selector.

    data object selector
    Figure 63. Data Object selector
    data object general properties
    Figure 64. Data Object general properties

    Field general properties can be selected by clicking on a field.

field selector
Figure 65. Field selector

+

field general properties
Figure 66. Field general properties
  • On workbench’s right side a new "Tool Bar" is provided that enables the selection of different context sensitive tool windows that will let the user do domain specific configurations. Currently four tool windows are provided for the following domains "Drools & jBPM", "OptaPlanner", "Persistence" and "Advanced" configurations.

    tool window selector
    Figure 67. Data modeller Tool Bar
    data object drools tool window
    Figure 68. Drools & jBPM tool window
    data object optaplanner tool window
    Figure 69. OptaPlanner tool window

    To see and use the OptaPlanner tool window, the user needs to have the role plannermgmt.

    data object persistence tool window
    Figure 70. Persistence tool window
    data object or field advanced tool window
    Figure 71. Advanced tool window

The "Source" tab shows an editor that allows the visualization and modification of the generated java code.

  • Round trip between the "Editor" and "Source" tabs is possible, and also source code preservation is provided. It means that not matter where the Java code was generated (e.g. Eclipse, Data modeller), the data modeller will only update the necessary code blocks to maintain the model updated.

    source editor tab
    Figure 72. Source editor

The "Overview" tab shows the standard metadata and version information as the other workbench editors.

10.7.7.2. Data Objects

A data model consists of data objects which are a logical representation of some real-world data. Such data objects have a fixed set of modeller (or application-owned) properties, such as its internal identifier, a label, description, package etc. Besides those, a data object also has a variable set of user-defined fields, which are an abstraction of a real-world property of the type of data that this logical data object represents.

Creating a data object can be achieved using the workbench "New Item - Data Object" menu option.

create new data object
Figure 73. New Data Object menu option

Both resource name and location are mandatory parameters. When the "Ok" button is pressed a new Java file will be created and a new editor instance will be opened for the file edition. The optional "Persistable" attribute will add by default configurations on the data object in order to make it a JPA entity. Use this option if your jBPM project needs to store data object’s information in a data base.

10.7.7.3. Properties & relationships

Once the data object has been created, it now has to be completed by adding user-defined properties to its definition. This can be achieved by pressing the "add field" button. The "New Field" dialog will be opened and the new field can be created by pressing the "Create" button. The "Create and continue" button will also add the new field to the Data Object, but won’t close the dialog. In this way multiple fields can be created avoiding the popup opening multiple times. The following fields can (or must) be filled out:

  • The field’s internal identifier (mandatory). The value of this field must be unique per data object, i.e. if the proposed identifier already exists within current data object, an error message will be displayed.

  • A label (optional): as with the data object definition, the user can define a user-friendly label for the data object field which is about to be created. This has no further implications on how fields from objects of this data object will be treated. If a label is defined, then this is how the field will be displayed throughout the data modeller tool.

  • A field type (mandatory): each data object field needs to be assigned with a type.

    This type can be either of the following:

    1. A 'primitive java object' type: these include most of the object equivalents of the standard Java primitive types, such as Boolean, Short, Float, etc, as well as String, Date, BigDecimal and BigInteger.

      create field with primitive type
      Figure 74. Primitive object field types
    2. A 'data object' type: any user defined data object automatically becomes a candidate to be defined as a field type of another data object, thus enabling the creation of relationships between them. A data object field can be created either in 'single' or in 'multiple' form, the latter implying that the field will be defined as a collection of this type, which will be indicated by selecting "List" checkbox.

types entity
Figure 75. Data object field types

+

+ .. A 'primitive java' type: these include java primitive types byte, short, int, long, float, double, char and boolean.

+

types primitive
Figure 76. Primitive field types

+

+

When finished introducing the initial information for a new field, clicking the 'Create' button will add the newly created field to the end of the data object’s fields table below:

new field was created
Figure 77. New field has been created

The new field will also automatically be selected in the data object’s field list, and its properties will be shown in the Field general properties editor. Additionally the field properties will be loaded in the different tool windows, in this way the field will be ready for edition in whatever selected tool window.

At any time, any field (without restrictions) can be deleted from a data object definition by clicking on the corresponding 'x' icon in the data object’s fields table.

10.7.7.4. Additional options

As stated before, both Data Objects as well as Fields require some of their initial properties to be set upon creation. Additionally there are three domains of properties that can be configured for a given Data Object. A domain is basically a set of properties related to a given business area. Current available domains are, "Drools & jJBPM", "Persistence" and the "Advanced" domain. To work on a given domain the user should select the corresponding "Tool window" (see below) on the right side toolbar. Every tool window usually provides two editors, the "Data Object" level editor and the "Field" level editor, that will be shown depending on the last selected item, the Data Object or the Field.

Drools & jBPM domain

The Drools & jBPM domain editors manages the set of Data Object or Field properties related to drools applications.

Drools & jBPM object editor

The Drools & jBPM object editor manages the object level drools properties

data object drools tool window
Figure 78. The data object’s properties
  • TypeSafe: this property allows to enable/disable the type safe behaviour for current type. By default all type declarations are compiled with type safety enabled. (See Drools for more information on this matter).

  • ClassReactive: this property allows to mark this type to be treated as "Class Reactive" by the Drools engine. (See Drools for more information on this matter).

  • PropertyReactive: this property allows to mark this type to be treated as "Property Reactive" by the Drools engine. (See Drools for more information on this matter).

  • Role: this property allows to configure how the Drools engine should handle instances of this type: either as regular facts or as events. By default all types are handled as a regular fact, so for the time being the only value that can be set is "Event" to declare that this type should be handled as an event. (See Drools Fusion for more information on this matter).

  • Timestamp: this property allows to configure the "timestamp" for an event, by selecting one of his attributes. If set the engine will use the timestamp from the given attribute instead of reading it from the Session Clock. If not, the engine will automatically assign a timestamp to the event. (See Drools Fusion for more information on this matter).

  • Duration: this property allows to configure the "duration" for an event, by selecting one of his attributes. If set the engine will use the duration from the given attribute instead of using the default event duration = 0. (See Drools Fusion for more information on this matter).

  • Expires: this property allows to configure the "time offset" for an event expiration. If set, this value must be a temporal interval in the form: [d][#h][#m][#s][[ms]] Where [ ] means an optional parameter and # means a numeric value. e.g.: 1d2h, means one day and two hours. (See Drools Fusion for more information on this matter).

  • Remotable: If checked this property makes the Data Object available to be used with jBPM remote services as REST, JMS and WS. (See jBPM for more information on this matter).

Drools & jJBPM field editor

The Drools & jBPM object editor manages the field level drools properties

field drools tool window
Figure 79. The data object’s field properties
  • Equals: checking this property for a Data Object field implies that it will be taken into account, at the code generation level, for the creation of both the equals() and hashCode() methods in the generated Java class. We will explain this in more detail in the following section.

  • Position: this field requires a zero or positive integer. When set, this field will be interpreted by the Drools engine as a positional argument (see the section below and also the Drools documentation for more information on this subject).

Persistence domain

The Persistence domain editors manages the set of Data Object or Field properties related to persistence.

Persistence domain object editor

Persistence domain object editor manages the object level persistence properties

data object persistence tool window
Figure 80. The data object’s properties
  • Persistable: this property allows to configure current Data Object as persistable.

  • Table name: this property allows to set a user defined database table name for current Data Object.

Persistence domain field editor

The persistence domain field editor manages the field level persistence properties and is divided in three sections.

field persistence tool window sections
Figure 81. Persistence domain field editor sections
Identifier:

A persistable Data Object should have one and only one field defined as the Data Object identifier. The identifier is typically a unique number that distinguishes a given Data Object instance from all other instances of the same class.

  • Is Identifier: marks current field as the Data Object identifier. A persistable Data Object should have one and only one field marked as identifier, and it should be a base java type, like String, Integer, Long, etc. A field that references a Data Object, or is a multiple field can not be marked as identifier. And also composite identifiers are not supported in this version. When a persistable Data Object is created an identifier field is created by default with the properly initializations, it’s strongly recommended to use this identifier.

  • Generation Strategy: the generation strategy establishes how the identifier values will be automatically generated when the Data Object instances are created and stored in a database. (e.g. by the forms associated to jBPM processes human tasks.) When the by default Identifier field is created, the generation strategy will be also automatically set and it’s strongly recommended to use this configuration.

  • Sequence Generator: the generator represents the seed for the values that will be used by the Generation Strategy. When the by default Identifier field is created the Sequence Generator will be also automatically generated and properly configured to be used by the Generation Strategy.

Column Properties:

The column properties section enables the customization of some properties of the database column that will store the field value.

  • Column name: optional value that sets the database column name for the given field.

  • Unique: When checked the unique property establishes that current field value should be a unique key when stored in the database. (if not set the default value is false)

  • Nullable: When checked establishes that current field value can be null when stored in a database. (if not set the default value is true)

  • Insertable: When checked establishes that column will be included in SQL INSERT statements generated by the persistence provider. (if not set the default value is true)

  • Updatable: When checked establishes that the column will be included SQL UPDATE statements generated by the persistence provider. (if not set the default value is true)

Relationship Properties:

When the field’s type is a Data Object type, or a list of a Data Object type a relationship type should be set in order to let the persistence provider to manage the relation. Fortunately this relation type is automatically set when such kind of fields are added to an already marked as persistable Data Object. The relationship type is set by the following popup.

field persistence tool window sections relationship dialog
Figure 82. Relationship configuration popup
  • Relationship type: sets the type of relation from one of the following options:

    One to one: typically used for 1:1 relations where "A is related to one instance of B", and B exists only when A exists. e.g. PurchaseOrder → PurchaseOrderHeader (a PurchaseOrderHeader exists only if the PurchaseOrder exists)

    One to many: typically used for 1:N relations where "A is related to N instances of B", and the related instances of B exists only when A exists. e.g. PurchaseOrder → PurchaseOrderLine (a PurchaseOrderLine exists only if the PurchaseOrder exists)

    Many to one: typically used for 1:1 relations where "A is related to one instance of B", and B can exist even without A. e.g. PurchaseOrder → Client (a Client can exist in the database even without an associated PurchaseOrder)

    Many to many: typically used for N:N relations where "A can be related to N instances of B, and B can be related to M instances of A at the same time", and both B an A instances can exits in the database independently of the related instances. e.g. Course → Student. (Course can be related to N Students, and a given Student can attend to M courses)

    When a field of type "Data Object" is added to a given persistable Data Object, the "Many to One" relationship type is generated by default.

    And when a field of type "list of Data Object" is added to a given persistable Data Object , the "One to Many" relationship is generated by default.

  • Cascade mode: Defines the set of cascadable operations that are propagated to the associated entity. The value cascade=ALL is equivalent to cascade={PERSIST, MERGE, REMOVE, REFRESH}. e.g. when A → B, and cascade "PERSIST or ALL" is set, if A is saved, then B will be also saved.

    The by default cascade mode created by the data modeller is "ALL" and it’s strongly recommended to use this mode when Data Objects are being used by jBPM processes and forms.

  • Fetch mode: Defines how related data will be fetched from database at reading time.

    EAGER: related data will be read at the same time. e.g. If A → B, when A is read from database B will be read at the same time.

    LAZY: reading of related data will be delayed usually to the moment they are required. e.g. If PurchaseOrder → PurchaseOrderLine the lines reading will be postponed until a method "getLines()" is invoked on a PurchaseOrder instance.

    The default fetch mode created by the data modeller is "EAGER" and it’s strongly recommended to use this mode when Data Objects are being used by jBPM processes and forms.

  • Optional: establishes if the right side member of a relationship can be null.

  • Mapped by: used for reverse relations.

Advanced domain

The advanced domain enables the configuration of whatever parameter set by the other domains as well as the adding of arbitrary parameters. As it will be shown in the code generation section every "Data Object / Field" parameter is represented by a java annotation. The advanced mode enables the configuration of this annotations.

Advanced domain Data Object / Field editor.

The advanced domain editor has the same shape for both Data Object and Field.

data object or field advanced tool window
Figure 83. Advanced domain editor.

The following operations are available

  • delete: enables the deletion of a given Data Object or Field annotation.

  • clear: clears a given annotation parameter value.

  • edit: enables the edition of a given annotation parameter value.

  • add annotation: The add annotation button will start a wizard that will let the addition of whatever java annotation available in the project dependencies.

    Add annotation wizard step #1: the first step of the wizard requires the entering of a fully qualified class name of an annotation, and by pressing the "search" button the annotation definition will be loaded into the wizard. Additionally when the annotation definition is loaded, different wizard steps will be created in order to enable the completion of the different annotation parameters. Required parameters will be marked with "*".

    add annotation wizard step1 annotation loaded
    Figure 84. Annotation definition loaded into the wizard.

    Whenever it’s possible the wizard will provide a suitable editor for the given parameters.

    add annotation wizard step2 enum param editor
    Figure 85. Automatically generated enum values editor for an Enumeration annotation parameter.

    A generic parameter editor will be provided when it’s not possible to calculate a customized editor

    add annotation wizard step2 generic param editor
    Figure 86. Generic annotation parameter editor

    When all required parameters has been entered and validated, the finish button will be enabled and the wizard can be completed by adding the annotation to the given Data Object or Field.

10.7.7.5. Generate data model code.

The data model in itself is merely a visual tool that allows the user to define high-level data structures, for them to interact with the Drools Engine on the one hand, and the jBPM platform on the other. In order for this to become possible, these high-level visual structures have to be transformed into low-level artifacts that can effectively be consumed by these platforms. These artifacts are Java POJOs (Plain Old Java Objects), and they are generated every time the data model is saved, by pressing the "Save" button in the top Data Modeller Menu. Additionally when the user round trip between the "Editor" and "Source" tab, the code is auto generated to maintain the consistency with the Editor view and vice versa.

save top
Figure 87. Save the data model from the top menu

The resulting code is generated according to the following transformation rules:

  • The data object’s identifier property will become the Java class’s name. It therefore needs to be a valid Java identifier.

  • The data object’s package property becomes the Java class’s package declaration.

  • The data object’s superclass property (if present) becomes the Java class’s extension declaration.

  • The data object’s label and description properties will translate into the Java annotations "@org.kie.api.definition.type.Label" and "@org.kie.api.definition.type.Description", respectively. These annotations are merely a way of preserving the associated information, and as yet are not processed any further.

  • The data object’s role property (if present) will be translated into the "@org.kie.api.definition.type.Role" Java annotation, that IS interpreted by the application platform, in the sense that it marks this Java class as a Drools Event Fact-Type.

  • The data object’s type safe property (if present) will be translated into the "@org.kie.api.definition.type.TypeSafe Java annotation. (see Drools)

  • The data object’s class reactive property (if present) will be translated into the "@org.kie.api.definition.type.ClassReactive Java annotation. (see Drools)

  • The data object’s property reactive property (if present) will be translated into the "@org.kie.api.definition.type.PropertyReactive Java annotation. (see Drools)

  • The data object’s timestamp property (if present) will be translated into the "@org.kie.api.definition.type.Timestamp Java annotation. (see Drools)

  • The data object’s duration property (if present) will be translated into the "@org.kie.api.definition.type.Duration Java annotation. (see Drools)

  • The data object’s expires property (if present) will be translated into the "@org.kie.api.definition.type.Expires Java annotation. (see Drools)

  • The data object’s remotable property (if present) will be translated into the "@org.kie.api.remote.Remotable Java annotation. (see jBPM)

A standard Java default (or no parameter) constructor is generated, as well as a full parameter constructor, i.e. a constructor that accepts as parameters a value for each of the data object’s user-defined fields.

The data object’s user-defined fields are translated into Java class fields, each one of them with its own getter and setter method, according to the following transformation rules:

  • The data object field’s identifier will become the Java field identifier. It therefore needs to be a valid Java identifier.

  • The data object field’s type is directly translated into the Java class’s field type. In case the field was declared to be multiple (i.e. 'List'), then the generated field is of the "java.util.List" type.

  • The equals property: when it is set for a specific field, then this class property will be annotated with the "@org.kie.api.definition.type.Key" annotation, which is interpreted by the Drools Engine, and it will 'participate' in the generated equals() method, which overwrites the equals() method of the Object class. The latter implies that if the field is a 'primitive' type, the equals method will simply compares its value with the value of the corresponding field in another instance of the class. If the field is a sub-entity or a collection type, then the equals method will make a method-call to the equals method of the corresponding data object’s Java class, or of the java.util.List standard Java class, respectively.

    If the equals property is checked for ANY of the data object’s user defined fields, then this also implies that in addition to the default generated constructors another constructor is generated, accepting as parameters all of the fields that were marked with Equals. Furthermore, generation of the equals() method also implies that also the Object class’s hashCode() method is overwritten, in such a manner that it will call the hashCode() methods of the corresponding Java class types (be it 'primitive' or user-defined types) for all the fields that were marked with Equals in the Data Model.

  • The position property: this field property is automatically set for all user-defined fields, starting from 0, and incrementing by 1 for each subsequent new field. However the user can freely changes the position among the fields. At code generation time this property is translated into the "@org.kie.api.definition.type.Position" annotation, which can be interpreted by the Drools Engine. Also, the established property order determines the order of the constructor parameters in the generated Java class.

As an example, the generated Java class code for the Purchase Order data object, corresponding to its definition as shown in the following figure purchase_example.jpg is visualized in the figure at the bottom of this chapter. Note that the two of the data object’s fields, namely 'header' and 'lines' were marked with Equals, and have been assigned with the positions 2 and 1, respectively).

generate purchase example
Figure 88. Purchase Order configuration
    package org.jbpm.examples.purchases;

    /**
    * This class was automatically generated by the data modeler tool.
    */
    @org.kie.api.definition.type.Label("Purchase Order")
    @org.kie.api.definition.type.TypeSafe(true)
    @org.kie.api.definition.type.Role(org.kie.api.definition.type.Role.Type.EVENT)
    @org.kie.api.definition.type.Expires("2d")
    @org.kie.api.remote.Remotable
    public class PurchaseOrder implements java.io.Serializable
    {

    static final long serialVersionUID = 1L;

    @org.kie.api.definition.type.Label("Total")
    @org.kie.api.definition.type.Position(3)
    private java.lang.Double total;

    @org.kie.api.definition.type.Label("Description")
    @org.kie.api.definition.type.Position(0)
    private java.lang.String description;

    @org.kie.api.definition.type.Label("Lines")
    @org.kie.api.definition.type.Position(2)
    @org.kie.api.definition.type.Key
    private java.util.List<org.jbpm.examples.purchases.PurchaseOrderLine> lines;

    @org.kie.api.definition.type.Label("Header")
    @org.kie.api.definition.type.Position(1)
    @org.kie.api.definition.type.Key
    private org.jbpm.examples.purchases.PurchaseOrderHeader header;

    @org.kie.api.definition.type.Position(4)
    private java.lang.Boolean requiresCFOApproval;

    public PurchaseOrder()
    {
    }

    public java.lang.Double getTotal()
    {
    return this.total;
    }

    public void setTotal(java.lang.Double total)
    {
    this.total = total;
    }

    public java.lang.String getDescription()
    {
    return this.description;
    }

    public void setDescription(java.lang.String description)
    {
    this.description = description;
    }

    public java.util.List<org.jbpm.examples.purchases.PurchaseOrderLine> getLines()
    {
    return this.lines;
    }

    public void setLines(java.util.List<org.jbpm.examples.purchases.PurchaseOrderLine> lines)
    {
    this.lines = lines;
    }

    public org.jbpm.examples.purchases.PurchaseOrderHeader getHeader()
    {
    return this.header;
    }

    public void setHeader(org.jbpm.examples.purchases.PurchaseOrderHeader header)
    {
    this.header = header;
    }

    public java.lang.Boolean getRequiresCFOApproval()
    {
    return this.requiresCFOApproval;
    }

    public void setRequiresCFOApproval(java.lang.Boolean requiresCFOApproval)
    {
    this.requiresCFOApproval = requiresCFOApproval;
    }

    public PurchaseOrder(java.lang.Double total, java.lang.String description,
    java.util.List<org.jbpm.examples.purchases.PurchaseOrderLine> lines,
    org.jbpm.examples.purchases.PurchaseOrderHeader header,
    java.lang.Boolean requiresCFOApproval)
    {
    this.total = total;
    this.description = description;
    this.lines = lines;
    this.header = header;
    this.requiresCFOApproval = requiresCFOApproval;
    }

    public PurchaseOrder(java.lang.String description,
    org.jbpm.examples.purchases.PurchaseOrderHeader header,
    java.util.List<org.jbpm.examples.purchases.PurchaseOrderLine> lines,
    java.lang.Double total, java.lang.Boolean requiresCFOApproval)
    {
    this.description = description;
    this.header = header;
    this.lines = lines;
    this.total = total;
    this.requiresCFOApproval = requiresCFOApproval;
    }

    public PurchaseOrder(
    java.util.List<org.jbpm.examples.purchases.PurchaseOrderLine> lines,
    org.jbpm.examples.purchases.PurchaseOrderHeader header)
    {
    this.lines = lines;
    this.header = header;
    }

    @Override
    public boolean equals(Object o)
    {
    if (this == o)
    return true;
    if (o == null || getClass() != o.getClass())
    return false;
    org.jbpm.examples.purchases.PurchaseOrder that = (org.jbpm.examples.purchases.PurchaseOrder) o;
    if (lines != null ? !lines.equals(that.lines) : that.lines != null)
    return false;
    if (header != null ? !header.equals(that.header) : that.header != null)
    return false;
    return true;
    }

    @Override
    public int hashCode()
    {
    int result = 17;
    result = 31 * result + (lines != null ? lines.hashCode() : 0);
    result = 31 * result + (header != null ? header.hashCode() : 0);
    return result;
    }

    }
10.7.7.6. Using external models

Using an external model means the ability to use a set for already defined POJOs in current project context. In order to make those POJOs available a dependency to the given JAR should be added. Once the dependency has been added the external POJOs can be referenced from current project data model.

There are two ways to add a dependency to an external JAR file:

  • Dependency to a JAR file already installed in current local M2 repository (typically associated the the user home).

  • Dependency to a JAR file installed in current KIE Workbench/Drools Workbench "Guvnor M2 repository". (internal to the application)

Dependency to a JAR file in local M2 repository

To add a dependency to a JAR file in local M2 repository follow this steps.

Save the project to update its dependencies.

When project is saved the POJOs defined in the external file will be available.

add dependency 4
Figure 92. Save project.
Dependency to a JAR file in current "Guvnor M2 repository".

To add a dependency to a JAR file in current "Guvnor M2 repository" follow this steps.

Open the Maven Artifact Repository editor.
add dependency guvnor m2 1
Figure 93. Guvnor M2 Repository editor.
Upload the file using the Upload button.
add dependency guvnor m2 3
Figure 95. File upload success.
Guvnor M2 repository files.

Once the file has been loaded it will be displayed in the repository files list.

add dependency guvnor m2 4
Figure 96. Files list.
Provide a GAV for the uploaded file (optional).

If the uploaded file is not a valid Maven JAR (don’t have a pom.xml file) the system will prompt the user in order to provide a GAV for the file to be installed.

add dependency guvnor m2 not gav 1
Figure 97. Not valid POM.
add dependency guvnor m2 not gav 2
Figure 98. Enter GAV manually.
Add dependency from repository.

Open the project editor (see bellow) and click on the "Add from repository" button to open the JAR selector to see all the installed JAR files in current "Guvnor M2 repository". When the desired file is selected the project should be saved in order to make the new dependency available.

add dependency guvnor m2 5
Figure 99. Select JAR from "Maven Artifact Repository".
Using the external objects

When a dependency to an external JAR has been set, the external POJOs can be used in the context of current project data model in the following ways:

  • External POJOs can be extended by current model data objects.

  • External POJOs can be used as field types for current model data objects.

The following screenshot shows how external objects are prefixed with the string " -ext- " in order to be quickly identified.

add dependency select external pojo
Figure 100. Identifying external objects.
10.7.7.7. Roundtrip and concurrency

Current version implements roundtrip and code preservation between Data modeller and Java source code. No matter where the Java code was generated (e.g. Eclipse, Data modeller), the data modeller will only create/delete/update the necessary code elements to maintain the model updated, i.e, fields, getter/setters, constructors, equals method and hashCode method. Also whatever Type or Field annotation not managed by the Data Modeler will be preserved when the Java sources are updated by the Data modeller.

Aside from code preservation, like in the other workbench editors, concurrent modification scenarios are still possible. Common scenarios are when two different users are updating the model for the same project, e.g. using the data modeller or executing a 'git push command' that modifies project sources.

From an application context’s perspective, we can basically identify two different main scenarios:

No changes have been undertaken through the application

In this scenario the application user has basically just been navigating through the data model, without making any changes to it. Meanwhile, another user modifies the data model externally.

In this case, no immediate warning is issued to the application user. However, as soon as the user tries to make any kind of change, such as add or remove data objects or properties, or change any of the existing ones, the following pop-up will be shown:

extchanges reopen ignore
Figure 101. External changes warning

The user can choose to either:

  • Re-open the data model, thus loading any external changes, and then perform the modification he was about to undertake, or

  • Ignore any external changes, and go ahead with the modification to the model. In this case, when trying to persist these changes, another pop-up warning will be shown:

    extchanges forcesave reopen
    Figure 102. Force save / re-open

    The "Force Save" option will effectively overwrite any external changes, while "Re-open" will discard any local changes and reload the model.

    "Force Save" overwrites any external changes!

Changes have been undertaken through the application

The application user has made changes to the data model. Meanwhile, another user simultaneously modifies the data model from outside the application context.

In this alternative scenario, immediately after the external user commits his changes to the asset repository (or e.g. saves the model with the data modeller in a different session), a warning is issued to the application user:

extchanges reopen ignore
Figure 103. External changes warning

As with the previous scenario, the user can choose to either:

  • Re-open the data model, thus losing any modifications that where made through the application, or

  • Ignore any external changes, and continue working on the model.

    One of the following possibilities can now occur: ** The user tries to persist the changes he made to the model by clicking the "Save" button in the data modeller top level menu. This leads to the following warning message:

    +

    extchanges forcesave reopen
    Figure 104. Force save / re-open

    The "Force Save" option will effectively overwrite any external changes, while "Re-open" will discard any local changes and reload the model.

10.7.8. Data Sets

A data set is basically a set of columns populated with some rows, a matrix of data composed of timestamps, texts and numbers. A data set can be stored in different systems: a database, an excel file, in memory or in a lot of other different systems. On the other hand, a data set definition tells the workbench modules how such data can be accessed, read and parsed.

Notice, it’s very important to make crystal clear the difference between a data set and its definition since the workbench does not take care of storing any data, it just provides an standard way to define access to those data sets regardless where the data is stored.

Let’s take for instance the data stored in a remote database. A valid data set could be, for example, an entire database table or the result of an SQL query. In both cases, the database will return a bunch of columns and rows. Now, imagine we want to get access to such data to feed some charts in a new workbench perspective. First thing is to create and register a data set definition in order to indicate the following:

  • where the data set is stored,

  • how can be accessed, read and parsed and

  • what columns contains and of which type.

This chapter introduces the available workbench tools for registering and handling data set definitions and how this definitions can be consumed in other workbench modules like, for instance, the Perspective Editor.

For simplicity sake we will be using the term data set to refer to the actual data set definitions as Data set and Data set definition can be considered synonyms under the data set authoring context.

10.7.8.1. Data Set Authoring Perspective

Everything related to the authoring of data sets can be found under the Data Set Authoring perspective which is accessible from the following top level menu entry: Extensions>Data Sets, as shown in the following screenshot.

DataSetAuthoringPerspective
Figure 105. Data Set Authoring Perspective

The center panel, shows a welcome screen, whilst the left panel contains the Data Set Explorer listing all the data sets available

This perspective is only intended to Administrator users, since defining data sets can be considered a low level task.

10.7.8.2. Data Set Explorer

The Data Set Explorer list the data sets present in the system. Every time the user clicks on the data set it shows a brief summary alongside the following information:

DataSetExplorer
Figure 106. Data Set Explorer
  • (1) A button for creating a new Data set

  • (2) The list of currently available Data sets

  • (3) An icon that represents the Data set’s provider type (Bean, SQL, CSV, etc)

  • (4) Details of current cache and refresh policy status

  • (5) Details of current size on backend (unit as rows) and current size on client side (unit in bytes)

  • (6) The button for editing the Data set. Once clicked the Data set editor screen is opened on the center panel

The next sections explains how to create, edit and fine tune data set definitions.

10.7.8.3. Data Set Creation

Clicking on the New Data Set button opens a new screen from which the user is able to create a new data set definition in three steps:

  • Provider type selection

    Specify the kind of the remote storage system (BEAN, SQL, CSV, ElasticSearch)

  • Provider configuration

    Specify the attributes for being able to look up data from the remote system. The configuration varies depending on the data provider type selected.

  • Data set columns & filter

    Live data preview, column types and initial filter configuration.

Step 1: Provider type selection

Allows the user’s specify the type of data provider of the data set being created.

This screen lists all the current available data provider types and helper popovers with descriptions. Each data provider is represented with a descriptive image:

DataSetDefTypeSelection
Figure 107. Provider type selection

Four types are currently supported:

  • Bean (Java class) - To generate a data set directly from Java

  • SQL - For getting data from any ANSI-SQL compliant database

  • CSV - To upload the contents of a remote or local CSV file

  • Elastic Search - To query and get documents stored on Elastic Search nodes as data sets

Once a type is selected, click on Next button to continue with the next workflow step.

Step 2: Configuration
DataSetDefConfigScreen
Figure 108. CSV Configuration

The provider type selected in the previous step will determine which configuration settings the system asks for.

DataSetDefConfigTypes
Figure 109. Configuration screen per data set type

The UUID attribute is a read only field as it’s generated by the system. It’s only intended for usage in API calls or specific operations.

Step 3: Data set columns and preview

After clicking on the Test button (see previous step), the system executes a data set lookup test call in order to check if the remote system is up and the data is available. If everything goes ok the user will see the following screen:

DataSetDefLivePreview
Figure 110. Data set preview

This screen shows a live data preview along with the columns the user wants to be part of the resulting data set. The user can also navigate through the data and apply some changes to the data set structure. Once finished, we can click on the Save button in order to register the new data set definition.

We can also change the configuration settings at any time just by going back to the configuration tab. We can repeat the Configuration>Test>Preview cycle as may times as needed until we consider it’s ready to be saved.

Columns

In the Columns tab area the user can select what columns are part of the resulting data set definition.

DataSetDefColumns
Figure 111. Data set columns
  • (1) To add or remove columns. Select only those columns you want to be part of the resulting data set

  • (2) Use the drop down image selector to change the column type

A data set may only contain columns of any of the following 4 types:

  • Label - For text values supporting group operations (similar to the SQL "group by" operator) which means you can perform data lookup calls and get one row per distinct value.

  • Text - For text values NOT supporting group operations. Typically for modeling large text columns such as abstracts, descriptions and the like.

  • Number - For numeric values. It does support aggregation functions on data lookup calls: sum, min, max, average, count, disctinct.

  • Date - For date or timestamp values. It does support time based group operations by different time intervals: minute, hour, day, month, year, …​

No matter which remote system you want to retrieve data from, the resulting data set will always return a set of columns of one of the four types above. There exists, by default, a mapping between the remote system column types and the data set types. The user is able to modify the type for some columns, depending on the data provider and the column type of the remote system. The system supports the following changes to column types:

  • Label <> Text - Useful when we want to enable/disable the categorization (grouping) for the target column. For instance, imagine a database table called "document" containing a large text column called "abstract". As we do not want the system to treat such column as a "label" we might change its column type to "text". Doing so, we are optimizing the way the system handles the data set and

  • Number <> Label - Useful when we want to treat numeric columns as labels. This can be used for instance to indicate that a given numeric column is not a numeric value that can be used in aggregation functions. Despite its values are stored as numbers we want to handle the column as a "label". One example of such columns are: an item’s code, an appraisal id., …​

BEAN data sets do not support changing column types as it’s up to the developer to decide which are the concrete types for each column.

Filter

A data set definition may define a filter. The goal of the filter is to leave out rows the user does not consider necessary. The filter feature works on any data provider type and it lets the user to apply filter operations on any of the data set columns available.

DataSetDefFilter
Figure 112. Data set filter

While adding or removing filter conditions and operations, the preview table on central area is updated with live data that reflects the current filter status.

There exists two strategies for filtering data sets and it’s also important to note that choosing between the two have important implications. Imagine a dashboard with some charts feeding from a expense reports data set where such data set is built on top of an SQL table. Imagine also we only want to retrieve the expense reports from the "London" office. You may define a data set containing the filter "office=London" and then having several charts feeding from such data set. This is the recommended approach. Another option is to define a data set with no initial filter and then let the individual charts to specify their own filter. It’s up to the user to decide on the best approach.

Depending on the case it might be better to define the filter at a data set level for reusing across other modules. The decision may also have impact on the performance since a filtered cached data set will have far better performance than a lot of individual non-cached data set lookup requests. (See the next section for more information about caching data sets).

Notice, for SQL data sets, the user can use both the filter feature introduced or, alternatively, just add custom filter criteria to the SQL sentence. Although, the first approach is more appropriated for non technical users since they might not have the required SQL language skills.

10.7.8.4. Data set editor

To edit an existing data set definition go the data set explorer, expand the desired data set definition and click on the Edit button. This will cause a new editor panel to be opened and placed on the center of the screen, as shown in the next screenshot:

DataSetDefEditor
Figure 113. Data set definition editor
DataSetDefEditorSelector
Figure 114. Editor selector
  • Save - To validate the current changes and store the data set definition.

  • Delete - To remove permanently from storage the data set definition. Any client module referencing the data set may be affected.

  • Validate - To check that all the required parameters exists and are correct, as well as to validate the data set can be retrieved with no issues.

  • Copy - To create a brand new definition as a copy of the current one.

Data set definitions are stored in the underlying GIT repository as JSON files. Any action performed is registered in the repository logs so it is possible to audit the change log later on.

10.7.8.5. Advanced settings

In the Advanced settings tab area the user can specify caching and refresh settings. Those are very important for making the most of the system capabilities thus improving the performance and having better application responsive levels.

DataSetDefAdvanced
Figure 115. Advanced settings
  • (1) To enable or disable the client cache and specify the maximum size (bytes).

  • (2) To enable or disable the backend cache and specify the maximum cache size (number of rows).

  • (3) To enable or disable automatic refresh for the Data set and the refresh period.

  • (4) To enable or disable the refresh on stale data setting.

Let’s dig into more details about the meaning of these settings.

10.7.8.6. Caching

The system provides caching mechanisms out-of-the-box for holding data sets and performing data operations using in-memory strategies. The use of these features brings a lot of advantages, like reducing the network traffic, remote system payload, processing times etc. On the other hand, it’s up to the user to fine tune properly the caching settings to avoid hitting performance issues.

Two cache levels are supported:

  • Client level

  • Backend level

The following diagram shows how caching is involved in any data set operation:

DataSetCacheArchitecture
Figure 116. Data set caching

Any data look up call produces a resulting data set, so the use of the caching techniques determines where the data lookup calls are executed and where the resulting data set is located.

Client cache

If ON then the data set involved in a look up operation is pushed into the web browser so that all the components that feed from this data set do not need to perform any requests to the backend since data set operations are resolved at a client side:

  • The data set is stored in the web browser’s memory

  • The client components feed from the data set stored in the browser

  • Data set operations (grouping, aggregations, filters and sort) are processed within the web browser, by means of a Javascript data set operation engine.

If you know beforehand that your data set will remain small, you can enable the client cache. It will reduce the number of backend requests, including the requests to the storage system. On the other hand, if you consider that your data set will be quite big, disable the client cache so as to not hitting with browser issues such as slow performance or intermittent hangs.

Backend cache

Its goal is to provide a caching mechanism for data sets on backend side.

This feature allows to reduce the number of requests to the remote storage system , by holding the data set in memory and performing group, filter and sort operations using the in-memory engine.

It’s useful for data sets that do not change very often and their size can be considered acceptable to be held and processed in memory. It can be also helpful on low latency connectivity issues with the remote storage. On the other hand, if your data set is going to be updated frequently, it’s better to disable the backend cache and perform the requests to the remote storage on each look up request, so the storage system is in charge of resolving the data set lookup request.

BEAN and CSV data providers relies by default on the backend cache, as in both cases the data set must be always loaded into memory in order to resolve any data lookup operation using the in-memory engine. This is the reason why the backend settings are not visible in the Advanced settings tab.

10.7.8.7. Refresh

The refresh feature allows for the invalidation of any cached data when certain conditions are meet.

DataSetDefRefreshSettings
Figure 117. Refresh settings
  • (1) To enable or disable the refresh feature.

  • (2) To specify the refresh interval.

  • (3) To enable or disable data set invalidation when the data is outdated.

The data set refresh policy is tightly related to data set caching, detailed in previous section. This invalidation mechanism determines the cache life-cycle.

Depending on the nature of the data there exist three main use cases:

  • Source data changes predictable - Imagine a database being updated every night. In that case, the suggested configuration is to use a "refresh interval = 1 day" and disable "refresh on stale data". That way, the system will always invalidate the cached data set every day. This is the right configuration when we know in advance that the data is going to change.

  • Source data changes unpredictable - On the other hand, if we do not know whether the database is updated every day, the suggested configuration is to use a "refresh interval = 1 day" and enable "refresh on stale data". If so the system, before invalidating any data, will check for modifications. On data modifications, the system will invalidate the current stale data set so that the cache is populated with fresh data on the next data set lookup call.

  • Real time scenarios - In real time scenarios caching makes no sense as data is going to be updated constantly. In this kind of scenarios the data sent to the client has to be constantly updated, so rather than enabling the refresh settings (remember this settings affect the caching, and caching is not enabled) it’s up to the clients consuming the data set to decide when to refresh. When the client is a dashboard then it’s just a matter of modifying the refresh settings in the Displayer Editor configuration screen and set a proper refresh period, "refresh interval = 1 second" for example.

10.7.9. Data Source Management

The data source management system provides the ability of defining data sources for accessing external databases. This data sources can be later used by other workbench components like the Data Sets.

10.7.9.1. Database Drivers

To be able to communicate with the target database a data source will need a database driver to access it. This is why the system additionally provides the ability of defining database drivers for the data sources operation. A database driver is basically a JDBC compliant driver. We will see them in the next topics.

10.7.9.2. Data Source Authoring Perspective

Everything related to the authoring of data sources and drivers can be found under the Data Source Authoring perspective accessible from the following top level menu entry: Extensions>Data Sources, as shown in the following screenshot.

DataSourceManagementPerspective
Figure 118. Data Source Authoring Perspective

This perspective is only intended for Administrator users, since defining data sources can be considered a low level task.

10.7.9.3. Data Source Explorer

The Data Source Explorer lists the data sources and drivers currently defined in the system, at the same time it provides the required actions for managing them.

DataSourceExplorer
Figure 119. Data Source Explorer
  • (1) Action link for creating a new data source

  • (2) List of currently available data sources

  • (3) Action link for creating a new driver

  • (4) List of currently available drivers

10.7.9.4. New Data Source Wizard

Clicking on the New Data Source action link opens the New Data Source Wizard:

NewDataSourceWizard
Figure 120. New Data Source Wizard

The following required parameters define a data source:

  • Name: A unique name for the data source definition.

  • Connection URL: A JDBC database connection url compliant with the selected driver type. This is an example of a connection url for a PostgreSQL database: jdbc:postgresql://localhost:5432/appformer.

  • User: A user name in the target database.

  • Password: The corresponding user password.

  • Driver: Selects the JDBC driver to be used for connecting to the target database. Note that the connection url format may vary depending on the driver, and different database vendors typically provides different drivers.

  • Test connection: Once clicked, the system will show a dialog similar to the one below showing the connection test status.

TestConnectionSuccessful
Figure 121. Test Connection Status

While not required, it’s recommended to use the test connection button to check the correctness of the data source parameters prior to finishing the data source creation.

10.7.9.5. Data Source Editor

The Data Source Editor is opened by clicking on a data source item in the Data Source Explorer.

The following screenshot shows the Data Source Editor opened for the data source of the example above.

DataSourceEditor
Figure 122. Data Source Editor
  • Main Panel: The main panel basically lets you modify the data source configuration parameters.

  • Test connection: Tests the connection.

It’s a recommended practice to test the connection prior saving a modified data source.

10.7.9.6. Data Source Content Browser

The data source content browser is opened by clicking on the Browse Content button, and enables the navigation through the database structure pointed by the data source. The navigation is performed in three levels, Schemas level, Current schema level and Current table level.

  • Schemas level: lists all the database schemas accessible by current data source. Which schemas are listed depends on the database access rights granted to the user which was used in the connection configuration. Similarly for the following item.

  • Current schema level: shows all the database tables for the selected schema.

  • Current table level: shows the table content for the selected table.

The following screenshots show the information shown at each level, for a user that realized the following navigation steps. Selects the "public" schema → Selects the "country" table.

Schema Selection:

Clicking on the Open button opens the Current schema level for the selected schema.

DataSourceContentBrowser1
Figure 123. Database schemas

Table Selection:

Clicking on the Open button opens the Current table level for the selected table.

DataSourceContentBrowser2
Figure 124. Schema tables

Table information:

The rows for the selected table are shown at this level.

DataSourceContentBrowser3
Figure 125. Table rows
10.7.9.7. External Data Sources

External data sources are typically not defined in current workbench, instead they exist in current container and for some containers like Wildfly 10 or the JBoss EAP 7 servers they can still be listed in read only mode. In this cases only the Data Source Content Browser is enabled.

ExternalDataSources
Figure 126. External Data Sources navigation
10.7.9.8. New Driver Wizard

Clicking on the New Driver action link opens the New Driver Wizard:

NewDriverWizard
Figure 127. New Driver Wizard

The following required parameters define a Driver:

  • Name: A unique name for the driver definition.

  • Driver Class Name: The java fully qualified name for the class that implements the JDBC driver contract.

  • Group Id: The maven group id for the artifact that contains the JDBC driver implementation.

  • Artifact Id: The maven artifact id for the artifact that contains the JDBC driver implementation.

  • Version: The maven version for the artifact that contains the JDBC driver implementation.

Some commercial database drivers (like Oracle) are not available in the maven central repository. You can use those by first uploading them via Artifact Repository perspective and then continue with the driver configuration as for the drivers available in the maven central repository.

10.7.9.9. Driver Editor

The Driver Editor is opened by clicking on a driver item in the Data Source Explorer.

The following screenshot shows the Driver Editor opened for the driver of the example above.

DriverEditor
Figure 128. Driver Editor
  • Main Panel: The main panel basically lets you modify the driver configuration parameters. See New Driver Wizard.

10.7.9.10. By Default Drivers

The system is shipped with a set of by default configured drivers for the most common used open source databases. And they are aligned with the latest database versions supported by the Wildfly 10 and the JBoss EAP 7 servers.

DefaultDrivers
Figure 129. By Default Drivers

10.8. Security management

This section describes how administrator users can manage the application’s users, groups and permissions using an intuitive and friendly user interface in order to configure who can access the different resources and features available.

10.8.1. Basic concepts

In order to understand the security management features provided, a few core concepts need to be introduced first.

10.8.1.1. Roles vs Groups

Users can be assigned with more than one role and/or group. It is always mandatory to assign at least one role to the user, otherwise he/she won’t be able to login. Roles are defined at application server level and they are part of the webapp’s web.xml descriptor. On the other hand, groups are a more flexible concept, since they can be defined at runtime.

10.8.1.2. Permissions

A permission is basically something the user can do within the application. Usually, an action related to a specific resource. For instance:

  • View a perspective

  • Save a project

  • View a repository

  • Delete a dashboard

A permission can be granted or denied and it can be global or resource specific. For instance:

  • Global: “Create new perspectives”

  • Specific: “View the home perspective”

As you can see, a permission is a resource + action pair. In the concrete case of a perspective we have: read, update, delete and create as the available actions. That means that there are four possible permissions that could be granted for perspectives.

Permissions do not necessarily need to be tied to a resource. Sometimes it is also neccessary to protect access to specific features, like for instance "generate a sales report". That means, permissions can be used not only to protect access to resources but also to custom features within the application.

10.8.1.3. Authorization policy

The set of permissions assigned to every role and/or group is called the authorization (or security) policy. Every application contains a single security policy which is used every time the system checks a permission.

The authorization policy file is stored in a file called WEB-INF/classes/security-policy.properties under the application’s WAR structure.

If no policy is defined then the authorization management features are disabled and the application behaves as if all the resources & features were granted by default.

Here is an example of a security policy file:

# Role "admin"
role.admin.permission.perspective.read=true
role.admin.permission.perspective.read.Dashboard=false

# Role "user"
role.user.permission.perspective.read=false
role.user.permission.perspective.read.Home=true
role.user.permission.perspective.read.Dashboard=true

Every entry defines a single permission which is assigned to a role/group. On application start up, the policy file is loaded and stored into memory.

10.8.1.4. Security provider

A security environment is usually provided by the use of a realm. Realms are used to restrict access to the different application’s resources. So realms contains the information about the users, groups, roles, permissions and any other related information.

In most typical scenarios the application’s security is delegated to the container’s security mechanism, which consumes a given realm at same time. It’s important to consider that there exist several realm implementations, for example Wildfly provides a realm based on the application-users.properties/application-roles.properties files, Tomcat provides a realm based on the tomcat-users.xml file, etc. So there is no single security realm to rely on, it can be different in each installation.

Due to the potential different security environments that have to be supported, the security module provides a well defined API with some default built-in security providers. A security provider is the formal name given to a concrete user and group management service implementation for a given realm.

The user & group management features available will depend on the security provider configured. If the built-in providers do not fit with the application’s security realm, it is easy to build and register your own provider.

10.8.2. Installation and setup

At the time of this writing, the application provides two pre-installed security providers:

  • Wildfly 10 / EAP 7 distribution - Both distributions use the Wildfly security provider configured for the use of the default realm files application-users.properties and application-roles.properties

  • Tomcat distribution - It uses the Tomcat security provider configured for the use of the default realm file tomcat-users.xml

Please read each provider’s documentation in order to apply the concrete settings for the target deployment environment.

On the other hand, when either using a custom security provider or using one of the availables, consider the following installation options:

  • Enable the security management feature on an existing WAR distribution

  • Setup and installation in an existing or new project

NOTE: If no security provider is installed, there will be no available user interface for managing the security realm. Once a security provider is installed and setup, the user and group management features are automatically enabled in the security management UI (see the Usage section below).

10.8.2.1. Enabling user & group management

Given an existing WAR distribution, follow these steps in order to install and enable the user & group management features:

  • Ensure the following libraries are present on WEB-INF/lib:

    • WEB-INF/lib/uberfire-security-management-api-?.jar

    • WEB-INF/lib/uberfire-security-management-backend-?.jar

  • Copy the the security provider library to WEB-INF/lib:

    • Eg: WEB-INF/lib/uberfire-security-management-wildfly-?.jar

    • If the provider requires additional libraries, copy them as well (read each provider’s documentation for more information).

  • Replace the whole content of the WEB-INF/classes/security-management.properties file, or if not present, create it. The settings present on this file depend on the concrete implementation used. Please read each provider’s documentation for more information.

  • If deploying on Wildfly or EAP, check if the WEB-INF/jboss-deployment-structure.xml requires any update (read each provider’s documentation for more information).

10.8.2.2. Disabling user & group management

The user & groups management features can be disabled, and thus no services or user interface will be available, by means of either:

  • Uninstalling the security provider from the application

    When no concrete security provider is installed, the user and group management features will be disabled and no services or user interface will be displayed to the user. This is the case for instance, in Weblogic and Websphere installations as there is no a security provider implementation available at the time of this writing.

  • Removing or commenting the security management configuration file

    Removing or commenting all the lines in the configuration file located at WEB-INF/classes/security-management.properties is another way to disable the user and group management features.

10.8.2.3. Upgrading an existing installation

In versions prior to 7, the only way to grant access to resources like Organizational Units, Repositories or Projects was to indicate which roles were able to access a given instance. Those roles were stored in GIT as part of the instance persistent status. The CLI was the tool used to add/remove roles:

  • remove-role-repo: remove role(s) from repository

  • add-role-org-unit: add role(s) to organizational unit

  • remove-role-org-unit: remove role(s) from organizational unit

  • add-role-project: add role(s) to project

  • remove-role-project: remove role(s) from project

As of version 7, the authorization policy is based on permissions. That means is no longer required to keep a list of roles per resource instance. What is required is to define proper permission entries into the active authorization policy using the security management UI (see the Usage section below).

The commands above are no longer required so they have been removed. Basically, what those commands did is to set what roles were able to read a specific item.

In order to guarantee backward compatibility with versions prior to 7, an automatic migration tool is bundled within the application, which converts the list of roles assigned to any organizational unit, repository or project into read permission entries of the security policy.

This tool is executed when the application start ups for the first time, during the security policy deployment. So existing customers, do not have to worry about it, as they will keep their security settings.

10.8.3. Usage

The Security Management perspective is available under the Home section in the top menu bar.

SecurityManagementMenuEntry
Figure 130. Link to the Security Management perspective

The next screenshot shows how this new perspective looks:

SecurityManagementHome
Figure 131. Security Management Home

This perspective supports:

  • List all the roles, groups and users available

  • Create & delete users and groups

  • Edit users, assign roles or groups, and change user properties

  • Edit both roles & groups security settings, which include:

    • The home perspective a user will be directed to after login

    • The permissions granted or denied to the different workbench resources and features available

All of the above together provides a complete users and groups management subsystem as well as a permission configuration UI for protecting access to specific resources or features.

The next sections provide a deep insight into all these features.

The user and group management related features can be entirely disabled. See the previous section Disabling user & group management. If that’s the case then both the Groups and _Users tabs will remain hidden from the user.
10.8.3.1. User management

By selecting the Users tab in the left sidebar, the application shows all the users present by default on the application’s security realm:

SecurityManagementUsersExplorer
  • Searching for users

In addition to listing all the users, search is also allowed:

+ When specifying the search pattern in the search box the users listed will be reduced to only those that matches the search pattern.

+

SecurityManagementUsersSearch

+ Search patterns depend on the concrete security provider being used by the application. Please read each provider’s documentation for more information.

  • Creating new users

    By clicking on the "New user +" anchor, a form is displayed on the screen’s right.

    SecurityManagementNewUserForm

This is a wizard like interface where the application asks for the new user name, a password as well as what roles/groups to assign.

  • Editing a user

After clicking on a user in the left sidebar, the user editor is opened on the screen’s right.

For instance, the details screen for the admin user when using the Wildfly security provider looks like the following screenshot:

SecurityManagementViewUser

Same screen but when using the Keycloak security provider looks as:

SecurityManagementViewUserKC

Note that when using the Keycloak provider, a new user attributes section is displayed, but it’s not present when using the Wildfly provider. This is due to the fact that the information and actions available always depend on each provider’s capabilities as explained in the Security provider capabilities section below.

Next is the type of information handled in the user’s details screen:

  • The user name

  • The user’s attributes

  • The assigned groups

  • The assigned roles

  • The permissions granted or denied

In order to update or delete an existing user, click on the Edit button present near to the username in the user editor screen:

SecurityManagementEditUser

Once the editor is in edit mode, different operations can be done (provided the security provider supports them):

For instance, to modify the set of roles and groups assigned to the user or to change the user’s password as well.

  • Permissions summary

The Permissions tab shows a summary of all the permissions assigned to this particular user. This is a very helpful view as it allows administrator users to verify if a target user has the right permission levels according to the security settings of its roles and groups.

SecurityManagementUserPermissions

Further details about how to assign permissions to roles and groups are in the Security Settings Editor section below.

  • Updating the user’s attributes

    User attributes can added or deleted using the actions available in the attributes table:

    SecurityManagementUserAttributes
  • Updating assigned groups

    From the Groups tab, a group selection popup is presented when clicking on the Add to groups button:

    SecurityManagementGroupsSelection

    This popup screen allows the user to search and select or deselect the groups assigned to the user.

  • Updating assigned roles

    From the Roles tab, a role selection popup is presented when clicking on Add to roles button:

    SecurityManagementRolesSelection

    This popup screen allows the user to search and select or deselect the roles assigned to the user.

  • Changing the user’s password

    A change password popup screen is presented when clicking on the Change password button:

    SecurityManagementChangePassword
  • Deleting users

    The user currently being edited can be deleted from the realm by clicking on the Delete button.

SecurityManagementDeleteUser
Security provider capabilities

Each security realm can provide support for different operations. For example consider the use of a Wildfly’s realm based on properties files. The contents for the applications-users.properties is like:

admin=207b6e0cc556d7084b5e2db7d822555c
salaboy=d4af256e7007fea2e581d539e05edd1b
maciej=3c8609f5e0c908a8c361ca633ed23844
kris=0bfd0f47d4817f2557c91cbab38bb92d
katy=fd37b5d0b82ce027bfad677a54fbccee
john=afda4373c6021f3f5841cd6c0a027244
jack=984ba30e11dda7b9ed86ba7b73d01481
director=6b7f87a92b62bedd0a5a94c98bd83e21
user=c5568adea472163dfc00c19c6348a665
guest=b5d048a237bfd2874b6928e1f37ee15e
kiewb=78541b7b451d8012223f29ba5141bcc2
kieserver=16c6511893651c9b4b57e0c027a96075

Notice that it’s based on key-value pairs where the key is the username, and the value is the hashed value for the user’s password. So a user is just represented by a key and its username, it does not have a name nor an address or any other meta information.

On the other hand, consider the use of a realm provided by a Keycloak server. The user information is composed by more meta-data, such as the surname, address, etc, as in the following image:

SecurityManagementViewUserKC

So the different services and client side components from the User and Group Management API are based on capabilities. Capabilities are used to expose or restrict the available functionality provided by the different services and client side components. Examples of capabilities are:

  • Create a user

  • Update a user

  • Delete a user

  • Update user’s attributes

  • Create a group

  • Update a group

  • Assign groups to a user

  • Assign roles to a user

Each security provider must specify a set of capabilities supported. From the previous examples, it is noted that the Wildfly security provider does not support the attributes management capability - the user is only composed by the user name. On the other hand the Keycloak provider does support this capability.

The different views and user interface components rely on the capabilities supported by each provider, so if a capability is not supported by the provider in use, the UI does not provide the views for the management of that capability. As an example, consider that a concrete provider does not support deleting users - the delete user button on the user interface will be not available.

Please take a look at the concrete service provider documentation to check all the supported capabilities for each one, the default ones can be found here.

10.8.3.2. Group management

By selecting the Groups tab in the left sidebar, the application shows all the groups present by default on the application’s security realm:

SecurityManagementGroupsExplorer
  • Searching for groups

In addition to listing all the groups, search is also allowed:

+ When specifying the search pattern in the search box the groups listed will be reduced to only those that matches the search pattern.

+

SecurityManagementGroupsSearch

+ Search patterns depend on the concrete security provider being used by the application. Please read each provider’s documentation for more information.

  • Creating new groups

    By clicking on the "New group +" anchor, a new screen will be presented on the center panel to perform a new group creation.

SecurityManagementNewGroup

After typing a name anc clicking Save, the next step is to assign users to it:

+

SecurityManagementNewGroupUserSelection

+ Clicking on the "Add selected users" button finishes the group creation.

  • Modifying a group

After clicking on a group in the left sidebar, the security settings editor for the selected group instance is opened on the screen’s right. Further details at the Security Settings Editor section.

  • Deleting groups

To delete an existing group just click on the Delete button.

10.8.3.3. Role management

By selecting the Roles tab in the left sidebar, the application shows all the application roles:

SecurityManagementRolesExplorer

Unlike users and groups, roles can not be created nor deleted as they come from the application’s web.xml descriptor. After clicking on a role in the left sidebar, the role editor is opened on the screen’s right, which is exactly the same security settings editor used for groups. Further details at the Security Settings Editor section.

SecurityManagementEditRole

That means both role and group based permissions can be defined. The main diference between roles and group are:

  • Roles are an application defined resource. They are defined as <security-role> entries in the application’s web.xml descriptor.

  • Groups are dynamic and can be defined at runtime. The installed security provider determines where groups instances are stored.

They can be used together without any trouble. Groups are recommended though as they are a more flexible than roles.

  • Searching for roles

In addition to listing all the roles, search is also allowed:

+ When specifying the search pattern in the search box the roles listed will be reduced to only those that matches the search pattern.

+

SecurityManagementRolesSearch

+ Search patterns depend on the concrete security provider being used by the application. Please read each provider’s documentation for more information.

10.8.4. Security Settings Editor

This editor is used to set several security settings for both roles and groups.

SecurityManagementSecuritySettsEditor

+

10.8.4.1. Home perspective

This is the perspective where the user is directed after login. This makes it possible to have different home pages for different users, since users can be assigned to different roles or groups.

10.8.4.2. Priority

It is used to determine what settings (home perspective, permissions, …​) have precedence for those users with more that one role or group assigned.

Without this setting, it won’t be possible to determine what role/group should take precedence. For instance, an administrative role has higher priority than a non-administrative one. For users with both administrative and non-administrative roles granted, administrative privileges will always win, provided the administrative role’s priority is greater than the other.

10.8.4.3. Permissions

Currently, the workbench support the following permission categories.

  • Workbench: General workbench permissions, not tied to any specific resource type.

  • Perspectives: If access to a perspective is denied then it will not be shown in any of application menus. Update, Delete and Create permissions change the behaviour of the perspective management plugin editor.

  • Organizational Units: Sets who can Create, Update or Delete organizational units from the Organizational Unit section at the Administration perspective. Sets also what organizational units are visible in the Project Explorer at the Project Authoring perspective.

  • Repositories: Sets who can Create, Update or Delete repositories from the Repositories section at the Administration perspective. Sets also what repositories are visible in the Project Explorer at the Project Authoring perspective.

  • Projects: In the Project Authoring perspective, sets who can Create, Update, Delete or Build projects from the Project Editor screen as well as what projects are visible in the Project Explorer.

For perspectives, organizational units, repositories and projects it is possible to define global permissions and add single instance exceptions afterwards. For instance, Read access can be granted to all the perspectives and deny access just to an individual perspective. This is called the grant all deny a few strategy.

SecurityManagementPerspectiveDenied

The opposite, deny all grant a few strategy is also supported:

SecurityManagementPerspectiveGranted
In the example above, the Update and Delete permissions are disabled as it does not makes sense to define such permissions if the user is not even able to read perspectives.

10.8.5. Security Policy Storage

The security policy is stored under the workbench’s VFS. Most concrete, in a GIT repo called “security”. The ACL table is stored in a file called “security-policy.properties” under the “authz” directory. Next is an example of the entries this file contains:

role.admin.home=HomePerspective
role.admin.priority=0
role.admin.permission.perspective.read=true
role.admin.permission.perspective.create=true
role.admin.permission.perspective.delete=true
role.admin.permission.perspective.update=true

Every time the ACL is modified from the security settings UI the changes are stored into the GIT repo.

Initially, when the application is deployed for the first time there is no security policy stored in GIT. However, the application might need to set-up a default policy with the different access profiles for each of the application roles.

In order to support default policies the system allows for declaring a security policy as part of the webapp’s content. This can be done just by placing a security-policy.properties file under the webapp’s resource classpath (the WEB-INF/classes directory inside the WAR archive is a valid one). On app start-up the following steps are executed:

  • Check if an active policy is already stored in GIT

  • If not, then check if a policy has been defined under the webapp’s classpath

  • If found, such policy is stored under GIT

The above is an auto-deploy mechanism which is used in the workbench to set-up its default security policy.

One slight variation of the deployment process is the ability to split the “security-policy.properties” file into small pieces so that it is possible, for example, to define one file per role. The split files must start by the “security-module-” prefix, for instance: “security-module-admin.properties”. The deployment mechanism will read and deploy both the "security-policy.properties" and all the optional “security-module-?.properties” found on the classpath.

Notice, despite using the split approach, the “security-policy.properties” must always be present as it is used as a marker file by the security subsystem in order to locate the other policy files. This split mechanism allows for a better organization of the whole security policy.

10.9. Embedding Workbench In Your Application

As we already know, Workbench provides a set of editors to author assets in different formats. According to asset’s format a specialized editor is used.

One additional feature provided by Workbench is the ability to embed it in your own (Web) Applications thru it’s standalone mode. So, if you want to edit rules, processes, decision tables, etc…​ in your own applications without switch to Workbench, you can.

In order to embed Workbench in your application all you’ll need is the Workbench application deployed and running in a web/application server and, from within your own web applications, an iframe with proper HTTP query parameters as described in the following table.

Table 24. HTTP query parameters for standalone mode
Parameter Name Explanation Allow multiple values Example

standalone

With just the presence of this parameter workbench will switch to standalone mode.

no

(none)

path

Path to the asset to be edited. Note that asset should already exists.

no

git://master@uf-playground/todo.md

perspective

Reference to an existing perspective name.

no

org.guvnor.m2repo.client.perspectives.GuvnorM2RepoPerspective

header

Defines the name of the header that should be displayed (useful for context menu headers).

yes

ComplementNavArea

Path and Perspective parameters are mutual exclusive, so can’t be used together.

10.10. Asset Management

10.10.1. Asset Management Overview

This section of the documentation describes the main features included that contribute to the Asset Management functionality provided in the KIE Workbench and KIE Drools Workbench. All the features described here are entirely optional, but the usage is recommended if you are planning to have multiple projects. All the Asset Management features try to impose good practices on the repository structure that will make the maintainace, versioning and distribution of the projects simple and based on standards. All the Asset Management features are implemented using jBPM Business Processes, which means that the logic can be reused for external applications as well as adapted for domain specific requirements when needed.

You must set the "kiemgmt" role to your user to be able to use the Asset Management Features

10.10.2. Managed vs Unmanaged Repositories

Since the creation of the assets management features repositories can be classified into Managed or Unmanaged.

10.10.2.1. Managed Repositories

All new assets management features are available for this type of repositories. Additionally a managed repository can be "Single Project" or "Multi Project".

A "Single Project" managed repository will contain just one Project. And a "Multi Project" managed repository can contain multiple Projects. All of them related through the same parent, and they will share the same group and version information.

10.10.2.2. Unmanaged Repositories

Assets management features are not available for this type or repositories and they basically behaves the same as the repositories created with previous workbench versions.

10.10.3. Asset Management Processes

There are 4 main processes which represent the stages of the Asset Management feature: Configure Repository, Promote Changes, Build and Release.

10.10.3.1. Configure Repository

The Configure Repository process is in charge of the post initialization of the repository. This process will be automatically triggered if the user selects to create a Managed Repository on the New repository wizzard. If they decide to use the governance feature the process will kick in and as soon as the repository is created. A new development and release branches will be created. Notice that the first time that this process is called, the master branch is picked and both branches (dev and release) will be based on it.

asset mgmt create repo

By default the asset management feature is not enabled so make sure to select Managed Repository on the New Repository Wizzard. When we work inside a managed repository, the development branch is selected for the users to work on. If multiple dev branches are created, the user will need to pick one.

10.10.3.2. Promote Changes Process

When some work is done in the developments branch and the users reach a point where the changes needs to be tested before going into production, they will start a new Promote Changes process so a more technical user can decide and review what needs to be promoted. The users belonging to the "kiemgmt" group will see a new Task in their Group Task List which will contain all the files that had being changed. The user needs to select the assets that will be promoting via the UI. The underlying process will be cherry-picking the commits selected by the user to the release branch. The user can specify that a review is needed by a more technical user.

This process can be repeated multiple times if needed before creating the artifacts for the release.

asset mgmt promote
10.10.3.3. Build Process

The Build process can be triggered to build our projects from different branches. This allows us to have a more flexible way to build and deploy our projects to different runtimes.

asset mgmt build
10.10.3.4. Release Process

The release process is triggered at any time when the user decided that it is time to generate a release of the project that he/she is working on. This process will build the project (calling the Build Process) and it will update all the maven artifacts to the next version.

asset mgmt release

10.10.4. Usage Flow

This section describes the common usage flow for the asset management features showing all the screens involved.

The first contact with the Asset Management features starts on the Repository creation.

new repo 1page wizzard

If the user chooses to create a Managed Respository a new page in the wizzard is enabled:

new repo 2page wizzard

When a managed repository is created the assets management configuration process is automatically launched in order to create the repository branches, and the corresponding project structure is also created.

10.11. Execution Server Management UI

The Execution Server Management UI allows users create and modify Server Templates and Containers, it also allows users manage Remote Servers. This screen is available via Deploy → Rule Deployments menu.

NewExecServerUI
Figure 132. Execution Server Management

The management UI is only available for KIE Managed Servers.

10.11.1. Server Templates

Server templates are used to define a common configuration that can be used for multiple server, thus the name: Template.

Server Templates can be created directly from the management UI or it’s automatically create when a server connects to controller and there isn’t a template definition for that remote server. Server templates may have one or more capabilities, such capabilities can’t be modified, if you need modify the capabilities you’ll have to create a new template. Here is the list of current capabilities:

  • Rule (Drools)

  • Process (jBPM)

  • Planning (Optaplanner)

For Planner capability it’s mandatory to enable Rule’s capability too.

In order to create a new Server Template you have to click at New Server Template button and follow the wizard. It’s also possible to create a container during Wizard, but for now let’s limit to just the template.

NewServerTemplateWizard
Figure 133. New Server Template Wizard

Once created you’ll get the new Template listed on the left hand side, with the new Server Template highlighted. On the right hand side you get the 2nd level navigation that lists Containers and Remote Servers that are related to selected Server Template.

ServerTemplates
Figure 134. Server Templates

On top of the navigation is also possible to delete the current Server Template or create a copy of it.

ServerTemplateActions
Figure 135. Server Template Actions

10.11.2. Container

A Container is a KIE Container configuration of the Server Template. Click the Add Container button to create a new container for the current Server Template.

The search area can help users find an specific KJARs that they are looking for.

NewContainerWizard
Figure 136. New Container Wizard

For Server Templates that have Process capabilities enabled, the Wizard has a 2nd optional step where users can configure some process related behaviors.

ProcessConfigNewContainerWizard
Figure 137. Process Configuration

Kie Base Name determines which Kie Base of the deployed artifact will be used.

Kie Session Name determines which Kie Session of the selected Kie Base will be used.

Please notice that configurations on this tab takes effect only if the deployed project contains some business processeses. It is not enough if the server template has the extension for processes enabled.

Once created the new Container will be displayed on the containers list just above the list of remote servers. Just after created a container is by default Stopped which is the only state that allows users to remove it.

NewContainer
Figure 138. Container

A Container has the following tabs available for management and/or configuration:

  • Status

  • Version Configuration

  • Process Configuration

Status tab lists all the Remote Servers that are running the active Container. Each Remote Server is rendered as a Card, which displays to users status and endpoint.

Only started Containers are deployed to remote servers.

ContainerStatus
Figure 139. Status Container

Version Configuration tab allow users change the current version of the Container. User’s can upgrade manually to a specific version using the "Upgrade" button, or enable/disable the Scanner. It’s also possible to execute a Scan Now operation, that will scan for new versions only once.

ContainerVersionConfiguration
Figure 140. Version Configuration

Process Configuration is the same form that is displayed during New Container Wizard for Template Servers that have Process Capability. If Template Server doesn’t have such capability, the action buttons will be disabled.

ContainerProcessConfiguration
Figure 141. Process Configuration

10.11.3. Remote Server

Remote Server is a Managed KIE Server instance running that has a controller configured.

By default Workbench comes with a Controller embedded.

The list of Remote Servers are displayed just under the list of Containers. Once selected the screens reveals the Remote Server details and a list of cards, each card represents a running Container.

RemoteServers
Figure 142. Remote Servers

11. Workbench Integration

11.1. REST

REST API calls to Knowledge Store allow you to manage the Knowledge Store content and manipulate the static data in the repositories of the Knowledge Store. The calls are asynchronous, that is, they continue their execution as a job after a call was performed. The job ID is returned by every call to allow (after the REST API call was performed) to request the job status and verify whether the job finished successfully. Parameters of these calls are provided in the form of JSON entities.

When using Java code to interface with the REST API, the classes used in POST operations or otherwise returned by various operations can be found in the (org.kie.workbench.services:)kie-wb-common-services JAR. All of the classes mentioned below can be found in the org.kie.workbench.common.services.shared.rest package in that JAR.

11.1.1. Job calls

Every Knowledge Store REST call returns its job ID after it was sent. This is necessary as the calls are asynchronous and you need to be able to reference the job to check its status as it goes through its lifecycle. During its lifecycle, a job can have the following statuses:

  • ACCEPTED: the job was accepted and is being processed

  • BAD_REQUEST: the request was not accepted as it contained incorrect content

  • RESOURCE_NOT_EXIST: the requested resource (path) does not exist

  • DUPLICATE_RESOURCE: the resource already exists

  • SERVER_ERROR: an error on the server occurred

  • SUCCESS: the job finished successfully

  • FAIL: the job failed

  • DENIED: the job was denied

  • GONE: the job ID could not be found

    A job can be GONE in the following cases: The job was explicitly removed The job finished and has been deleted from the status cache (the job is removed from status cache after the cache has reached its maximum capacity) ** The job never existed

The following job calls are provided:

[GET] /jobs/{jobID}

Returns the job status

[DELETE] /jobs/{jobID}

Removes the job: If the job is not yet being processed, this will remove the job from the job queue. However, this will not cancel or stop an ongoing job

11.1.2. Repository calls

Repository calls to the Knowledge Store allow you to manage Git repositories and projects inside them.

The following repositories calls are provided:

[GET] /repositories

Gets information about the repositories in the Knowledge Store

[GET] /repositories/{repositoryName}

Gets information about the repository

[POST] /repositories

Creates a new empty repository or a new repository cloned from an existing (git) repository defined by RepositoryRequest JSON entity

[DELETE] /repositories/{repositoryName}

Removes the repository from the Knowledge Store

[GET] /repositories/{repositoryName}/projects/

Gets information about all projects in the repository

[POST] /repositories/{repositoryName}/projects/

Creates a project in the repository defined by ProjectRequest JSON entity

[DELETE] /repositories/{repositoryName}/projects/{projectName}

Deletes the project in the repository

11.1.3. Organizational unit calls

Organizational unit calls to the Knowledge Store allow you to manage organizational units and organize the connected Git repositories.

The following organizationalUnits calls are provided:

[GET] /organizationalunits

Gets all organizational units

[GET] /organizationalunits/{organizationalUnitName}

Gets a single organizational unit

[POST] /organizationalunits

Creates an organizational unit described by OrganizationalUnit JSON entity

[POST] /organizationalunits/{organizationalUnitName}

Updates the organizational unit described by OrganizationalUnit JSON entity

[DELETE] /organizationalunits/{organizationalUnitName}

Deletes the organizational unit

[POST] /organizationalunits/{organizationalUnitName}/repositories/{repositoryName}

Adds the repository to the organizational unit

[DELETE] /organizationalunits/{organizationalUnitName}/repositories/{repositoryName}

Removes the repository from the organizational unit

11.1.4. Maven calls

Maven calls to a project in the Knowledge Store allow you compile, test, install, and deploy projects.

The following maven calls are provided:

[POST] /repositories/{repositoryName}/projects/{projectName}/maven/compile

Compiles the project (equivalent to mvn compile)

[POST] /repositories/{repositoryName}/projects/{projectName}/maven/test

Tests the project (equivalent to mvn test)

[POST] /repositories/{repositoryName}/projects/{projectName}/maven/install

Installs the project (equivalent to mvn install)

[POST] /repositories/{repositoryName}/projects/{projectName}/maven/deploy

Deploys the project (equivalent to mvn deploy)

11.1.5. REST summary

The URL templates in the table below are relative the following URL:

  • http://{server}:{port}/kie-wb/rest

Table 25. Knowledge Store REST calls
URL Template Type Description

/jobs/{jobID}

GET

return the job status

/jobs/{jobID}

DELETE

remove the job

/organizationalunits

GET

return a list of organizational units

/organizationalunits/{organizationalUnitName}

GET

return a single organizational unit

/organizationalunits

POST

create an organizational unit

/organizationalunits/{organizationalUnitName}

POST

update the organizational unit

/organizationalunits/{organizationalUnitName}

DELETE

delete the organizational unit

/organizationalunits/{organizationalUnitName}/repositories/{repositoryName}

POST

add the repository to the organizational unit

/organizationalunits/{organizationalUnitName}/repositories/{repositoryName}

DELETE

remove the repository from the organizational unit

/repositories

GET

return a list of repositories

/repositories/{repositoryName}

GET

return a single repository

/repositories

POST

create or clone the repository

/repositories/{repositoryName}

DELETE

remove the repository

/repositories/{repositoryName}/projects

GET

get a list of projects in the repository

/repositories/{repositoryName}/projects

POST

create a project in the repository

/repositories/{repositoryName}/projects/{projectName}

DELETE

delete the project in the repository

/repositories/{repositoryName}/projects/{projectName}/maven/compile

POST

compile the project

/repositories/{repositoryName}/projects/{projectName}/maven/test

POST

test the project

/repositories/{repositoryName}/projects/{projectName}/maven/install

POST

install the project

/repositories/{repositoryName}/projects/{projectName}/maven/deploy

POST

deploy the project

11.2. Keycloak SSO integration

Single Sign On (SSO) and related token exchange mechanisms are becoming the most common scenario for the authentication and authorization in different environments on the web, specially when moving into the cloud.

This section talks about the integration of Keycloak with jBPM or Drools applications in order to use all the features provided on Keycloak. Keycloak is an integrated SSO and IDM for browser applications and RESTful web services. Lean more about it in the Keycloak’s home page.

The result of the integration with Keycloak has lots of advantages such as:

  • Provide an integrated SSO and IDM environment for different clients, including jBPM and Drools workbenches

  • Social logins - use your Facebook, Google, Linkedin, etc accounts

  • User session management

  • And much more…​

Next sections cover the following integration points with Keycloak:

  • Workbench authentication through a Keycloak server

    It basically consists of securing both web client and remote service clients through the Keycloak SSO. So either web interface or remote service consumers ( whether a user or a service ) will authenticate into trough KC.

  • Execution server authentication through a Keycloak server

    Consists of securing the remote services provided by the execution server (as it does not provides web interface). Any remote service consumer ( whether a user or a service ) will authenticate trough KC.

  • Consuming remote services

    This section describes how a third party clients can consume the remote service endpoints provided by both Workbench and Execution Server, such as the REST API or remote file system services.

11.2.1. Scenario

Consider the following diagram as the environment for this document’s example:

Keycloak is a standalone process that provides remote authentication, authorization and administration services that can be potentially consumed by one or more jBPM applications over the network.

KeyCloak sso scenario

Consider these main steps for building this environment:

  • Install and setup a Keycloak server

  • Create and setup a Realm for this example - Configure realm’s clients, users and roles

  • Install and setup the SSO client adapter & jBPM application

Note: The resulting environment and the different configurations for this document are based on the jBPM (KIE) Workbench, but same ones can also be applied for the KIE Drools Workbench as well.

11.2.2. Install and setup a Keycloak server

Keycloak provides an extensive documentation and several articles about the installation on different environments. This section describes the minimal setup for being able to build the integrated environment for the example. Please refer to the Keycloak documentation if you need more information.

Here are the steps for a minimal Keycloak installation and setup:

  • Download latest version of Keycloak from the Downloads section. This example is based on Keycloak 1.9.0.Final

  • Unzip the downloaded distribution of Keycloak into a folder, let’s refer it as

    $KC_HOME
  • Run the KC server - This example is based on running both Keycloak and jBPM on same host. In order to avoid port conflicts you can use a port offset for the Keycloak’s server as:

    $KC_HOME/bin/standalone.sh -Djboss.socket.binding.port-offset=100
  • Create a Keycloak’s administration user - Execute the following command to create an admin user for this example:

    $KC_HOME/bin/add-user.sh -r master -u 'admin' -p 'admin'

The Keycloak administration console will be available at http://localhost:8180/auth/admin (use the admin/admin for login credentials).

11.2.3. Create and setup the demo realm

Security realms are used to restrict the access for the different application’s resources.

Once the Keycloak server is running next step is about creating a realm. This realm will provide the different users, roles, sessions, etc for the jBPM application/s.

Keycloak provides several examples for the realm creation and management, from the official examples to different articles with more examples.

Follow these steps in order to create the demo realm used later in this document:

  • Go to the Keycloak administration console and click on Add realm button. Give it the name demo.

  • Go to the Clients section (from the main admin console menu) and create a new client for the demo realm:

    • Client ID: kie

    • Client protocol: openid-connect

    • Acces type: confidential

    • Root URL: http://localhost:8080

    • Base URL: /kie-wb-6.4.0.Final

    • Redirect URIs: /kie-wb-6.4.0.Final/*

The resulting kie client settings screen:

kie client settings

Note: As you can see in the above settings it’s being considered the value kie-wb-6.4.0.Final for the application’s context path. If your jbpm application will be deployed on a different context path, host or port, just use your concrete settings here.

Last step for being able to use the demo realm from the jBPM workbench is create the application’s user and roles:

  • Go to the Roles section and create the roles admin,_kiemgmt and _rest-all

  • Go to the Users section and create the admin user. Set the password with value "password" in the credentials tab, unset the temporary switch.

  • In the Users section navigate to the Role Mappings tab and assign the admin, kiemgmt and rest-all roles to the admin user

admin user roles

At this point a Keycloak server is running on the host, setup with a minimal configuration set. Let’s move to the jBPM workbench setup.

11.2.4. Install and setup jBPM Workbench

For this tutorial let’s use a Wildfly as the application server for the jBPM workbench, as the jBPM installer does by default.

Let’s assume, after running the jBPM installer, the $JBPM_HOME as the root path for the Wildfly server where the application has been deployed.

11.2.4.1. Install the KC adapter

In order to use the Keycloak’s authentication and authorization modules from the jBPM application, the Keycloak adapter for Wildfly must be installed on our server at $JBPM_HOME. Keycloak provides multiple adapters for different containers out of the box, if you are using another container or need to use another adapter, please take a look at the adapters configuration from Keycloak docs. Here are the steps to install and setup the adapter for Wildfly 8.2.x:

  • Download the adapter from here

  • Execute the following commands on your shell:

    cd $JBPM_HOME/unzip keycloak-wf8-adapter-dist.zip // Install the KC client adapter
    
    cd $JBPM_HOME/bin
    ./standalone.sh -c standalone-full.xml // Setup the KC client adapter.
    
    // ** Once server is up, open a new command line terminal and run:
    cd $JBPM_HOME/bin
    ./jboss-cli.sh -c --file=adapter-install.cli
11.2.4.2. Configure the KC adapter

Once installed the KC adapter into Wildfly, next step is to configure the adapter in order to specify different settings such as the location for the authentication server, the realm to use and so on.

Keycloak provides two ways of configuring the adapter:

  • Per WAR configuration

  • Via Keycloak subsystem

In this example let’s use the second option, use the Keycloak subsystem, so our WAR is free from this kind of settings. If you want to use the per WAR approach, please take a look here.

Edit the configuration file $JBPM_HOME/standalone/configuration/standalone-full.xml and locate the subsystem configuration section. Add the following content:

<subsystem xmlns="urn:jboss:domain:keycloak:1.1">
  <secure-deployment name="kie-wb-6.4.0-Final.war">
    <realm>demo</realm>
    <realm-public-key>MIIBIjANBgkqhkiG9w0BAQEFAAOCA...</realm-public-key>
    <auth-server-url>http://localhost:8180/auth</auth-server-url>
    <ssl-required>external</ssl-required>
    <resource>kie</resource>
    <enable-basic-auth>true</enable-basic-auth>
    <credential name="secret">925f9190-a7c1-4cfd-8a3c-004f9c73dae6</credential>
    <principal-attribute>preferred_username</principal-attribute>
  </secure-deployment>
</subsystem>

If you have imported the example json files from this document in step 2, you can just use same configuration as above by using your concrete deployment name . Otherwise please use your values for these configurations:

  • Name for the secure deployment - Use your concrete application’s WAR file name

  • Realm - Is the realm that the applications will use, in our example, the demo realm created the previous step.

  • Realm Public Key - Provide here the public key for the demo realm. It’s not mandatory, if it’s not specified, it will be retrieved from the server. Otherwise, you can find it in the Keycloak admin console → Realm settings ( for demo realm ) → Keys

  • Authentication server URL - The URL for the Keycloak’s authentication server

  • Resource - The name for the client created on step 2. In our example, use the value kie.

  • Enable basic auth - For this example let’s enable Basic authentication mechanism as well, so clients can use both Token (Baerer) and Basic approaches to perform the requests.

  • Credential - Use the password value for the kie client. You can find it in the Keycloak admin console → Clients → kie → Credentials tab → Copy the value for the secret.

For this example you have to take care about using your concrete values for secure-deployment name, realm-public-key and credential password. You can find detailed information about the KC adapter configurations here.

11.2.4.3. Run the environment

At this point a Keycloak server is up and running on the host, and the KC adapter is installed and configured for the jBPM application server. You can run the application using:

$JBPM_HOME/bin/standalone.sh -c standalone-full.xml

You can navigate into the application once the server is up at:

 http://localhost:8080/kie-wb-6.4.0.Final
jbpm login screen

Use your Keycloak’s admin user credentials to login: admin/password.

11.2.5. Securing workbench remote services via Keycloak

Both jBPM and Drools workbenches provides different remote service endpoints that can be consumed by third party clients using the remote API.

In order to authenticate those services thorough Keycloak the BasicAuthSecurityFilter must be disabled, apply those modifications for the the WEB-INF/web.xml file (app deployment descriptor) from jBPM’s WAR file:

  • Remove the following filter from the deployment descriptor:

    <filter>
      <filter-name>HTTP Basic Auth Filter</filter-name>
      <filter-class>org.uberfire.ext.security.server.BasicAuthSecurityFilter</filter-class>
      <init-param>
        <param-name>realmName</param-name>
        <param-value>KIE Workbench Realm</param-value>
      </init-param>
    </filter>
    
    <filter-mapping>
      <filter-name>HTTP Basic Auth Filter</filter-name>
      <url-pattern>/rest/*</url-pattern>
      <url-pattern>/maven2/*</url-pattern>
      <url-pattern>/ws/*</url-pattern>
    </filter-mapping>
  • Constraint the remote services URL patterns as:

    <security-constraint>
      <web-resource-collection>
        <web-resource-name>remote-services</web-resource-name>
        <url-pattern>/rest/*</url-pattern>
        <url-pattern>/maven2/*</url-pattern>
        <url-pattern>/ws/*</url-pattern>
      </web-resource-collection>
      <auth-constraint>
        <role-name>rest-all</role-name>
      </auth-constraint>
    </security-constraint>

Important note: The user that consumes the remote services must be member of role rest-all. As on described previous steps, the admin user in this example it’s already a member of the rest-all role.

11.2.6. Securing workbench’s file system services via Keycloak

In order to consume other remote services such as the file system ones (e.g. remote GIT), a specific Keycloak login module must be used for the application’s security domain in the $JBPM_HOME/standalone/configuration/standalone-full.xml file. By default the workbench uses the other security domain, so the resulting configuration on the _$JBPM_HOME/standalone/configuration/standalone-full.xml should be such as:

<security-domain name="other" cache-type="default">
    <authentication>
        <login-module code="org.keycloak.adapters.jaas.DirectAccessGrantsLoginModule" flag="required">
            <!-- Parameter value can be a file system absolute path or a classpath (e.g. "classpath:/some-path/kie-git.json")-->
            <module-option name="keycloak-config-file" value="$JBPM_HOME/kie-git.json"/>
        </login-module>
    </authentication>
</security-domain>

Note that:

  • The login modules on the other security domain in the $JBPM_HOME/standalone/configuration/standalone-full.xml file must be REPLACED by the above given one.

  • Replace $JBPM_HOME/kie-git.json by the path (on file system) or the classpath (e.g. classpath:/some-path/kie-git.json) for the json configuration file used for the remote services client. Please continue reading in order to create this Keycloak client and how to obtain this json file.

At this point, remote services that use JAAS for the authentication process, such as the file system ones ( e.g. GIT ), are secured by Keycloak using the client specified in the above json configuration file. So let’s create this client on Keycloak and generate the required JSON file:

  • Navigate to the KC administration console and create a new client for the demo realm using kie-git as name.

  • Enable Direct Access Grants Enabled option

  • Disable Standard Flow Enabled option

  • Use a confidential access type for this client. See below image as example:

kie git client settings
  • Go to the Installation tab in same kie-git client configuration screen and export using the Keycloak OIDC JSON type.

  • Finally copy this generated JSON file into an accessible directory on the server’s file system or add it in the application’s classpath. Use this path value as the keycloak-config-file argument for the above configuration of the org.keycloak.adapters.jaas.DirectAccessGrantsLoginModule login module.

  • More information about Keycloak JAAS Login modules can be found here.

At this point, the internal Git repositories can be cloned by all users authenticated via the Keycloak server:

# Command example:
git clone ssh://admin@localhost:8001/system

11.2.7. Execution server

The KIE Execution Server provides a REST API than can be consumed for any third party clients,. This this section is about how to integration the KIE Execution Server with the Keycloak SSO in order to delegate the third party clients identity management to the SSO server.

Consider the above environment running, so consider having:

Follow these steps in order to add an execution server into this environment:

  • Create the client for the execution server on Keycloak

  • Install setup and the Execution server ( with the KC client adapter )

11.2.7.1. Create the execution server’s client on Keycloak

As per each execution server is going to be deployed, you have to create a new client on the demo realm in Keycloak.:

  • Go to the KC admin console → Clients → New client

  • Name: kie-execution-server

  • Root URL: http://localhost:8280/

  • Client protocol: openid-connect

  • Access type: confidential ( or public if you want so, but not recommended for production environments)

  • Valid redirect URIs: /kie-server-6.4.0.Final/*

  • Base URL: /kie-server-6.4.0.Final

In this example the admin user already created on previous steps is the one used for the client requests. So ensure that the admin user is member of the role kie-server in order to use the execution server’s remote services. If the role does not exist, create it.

Note: This example considers that the execution server will be configured to run using a port offset of 200, so the HTTP port will be available at localhost:8280.

11.2.7.2. Install and setup the KC adapter on the execution server

At this point, a client named kie-execution-server is ready on the KC server to use from the execution server.

Let’s install, setup and deploy the execution server:

  • Install another Wildfly server to use for the execution server and the KC client adapter as well. You can follow above instructions for the Workbench or follow the official adapters documentation

  • Edit the standalone-full.xml file from the Wildfly server’s configuration path and configure the KC subsystem adapter as:

    <secure-deployment name="kie-server-6.4.0.Final.war">
        <realm>demo</realm>
        <realm-public-key>MIGfMA0GCSqGSIb...</realm-public-key>
        <auth-server-url>http://localhost:8180/auth</auth-server-url>
        <ssl-required>external</ssl-required>
        <resource>kie-execution-server</resource>
        <enable-basic-auth>true</enable-basic-auth>
        <credential name="secret">e92ec68d-6177-4239-be05-28ef2f3460ff</credential>
        <principal-attribute>preferred_username</principal-attribute>
    </secure-deployment>

Consider your concrete environment settings if different from this example:

  • Secure deployment name → use the name of the execution server war file being deployed

  • Public key → Use the demo realm public key or leave it blank, the server will provide one if so

  • Resource → This time, instead of the kie client used in the WB configuration, use the kie-execution-server client

  • Enable basic auth → Up to you. You can enable Basic auth for third party service consumers

  • Credential → Use the secret key for the kie-execution-server client. You can find it in the Credentialstab of the KC admin console

11.2.7.3. Deploy and run the execution server

Just deploy the execution server in Wildfly using any of the available mechanisms. Run the execution server using this command:

$EXEC_SERVER_HOME/bin/standalone.sh -c standalone-full.xml -Djboss.socket.binding.port-offset=200 -Dorg.kie.server.id=<ID> -Dorg.kie.server.user=<USER> -Dorg.kie.server.pwd=<PWD> -Dorg.kie.server.location=<LOCATION_URL>  -Dorg.kie.server.controller=<CONTROLLER_URL> -Dorg.kie.server.controller.user=<CONTROLLER_USER> -Dorg.kie.server.controller.pwd=<CONTOLLER_PASSWORD>

Example:

$EXEC_SERVER_HOME/bin/standalone.sh -c standalone-full.xml -Djboss.socket.binding.port-offset=200 -Dorg.kie.server.id=kieserver1 -Dorg.kie.server.user=admin -Dorg.kie.server.pwd=password -Dorg.kie.server.location=http://localhost:8280/kie-server-6.4.0.Final/services/rest/server -Dorg.kie.server.controller=http://localhost:8080/kie-wb-6.4.0.Final/rest/controller -Dorg.kie.server.controller.user=admin -Dorg.kie.server.controller.pwd=password

mportant note: The users that will consume the execution server remote service endpoints must have the role kie-server assigned. So create and assign this role in the KC admin console for the users that will consume the execution server remote services.

Once up, you can check the server status as (considered using Basic authentication for this request, see nextConsuming remote services for more information):

curl http://admin:password@localhost:8280/kie-server-6.4.0.Final/services/rest/server/

11.2.8. Consuming remote services

In order to use the different remote services provided by the Workbench or by an Execution Server, your client must be authenticated on the KC server and have a valid token to perform the requests.

Remember that in order to use the remote services, the authenticated user must have assigned:

  • The role rest-all for using the WB remote services

  • The role kie-server for using the Execution Server remote services

Please ensure necessary roles are created and assigned to the users that will consume the remote services on the Keycloak admin console.

You have two options to consume the different remove service endpoints:

  • Using basic authentication, if the application’s client supports it

  • Using Bearer ( token) based authentication

11.2.8.1. Using basic authentication

If the KC client adapter configuration has the Basic authentication enabled, as proposed in this guide for both WB (step 3.2) and Execution Server, you can avoid the token grant/refresh calls and just call the services as the following examples.

Example for a WB remote repositories endpoint:

curl http://admin:password@localhost:8080/kie-wb-6.4.0.Final/rest/repositories

Example to check the status for the Execution Server:

curl http://admin:password@localhost:8280/kie-server-6.4.0.Final/services/rest/server/
11.2.8.2. Using token based authentication

First step is to create a new client on Keycloak that allows the third party remote service clients to obtain a token. It can be done as:

  • Go to the KC admin console and create a new client using this configuration:

    • Client id: kie-remote

    • Client protocol: openid-connect

    • Access type: public

    • Valid redirect URIs: http://localhost/

  • As we are going to manually obtain a token and invoke the service let’s increase the lifespan of tokens slightly. In production access tokens should have a relatively low timeout, ideally less than 5 minutes:

    • Go to the KC admin console

    • Click on your Realm Settings

    • Click on Tokens tab

    • Change the value for Access Token Lifespan to 15 minutes ( That should give us plenty of time to obtain a token and invoke the service before it expires )

Once a public client for our remote clients has been created, you can now obtain the token by performing an HTTP request to the KC server’s tokens endpoint. Here is an example for command line:

RESULT=`curl --data "grant_type=password&client_id=kie-remote&username=admin&passwordpassword=<the_client_secret>" http://localhost:8180/auth/realms/demo/protocol/openid-connect/token`
TOKEN=`echo $RESULT | sed 's/.*access_token":"//g' | sed 's/".*//g'`

At this point, if you echo the $TOKEN it will output the token string obtained from the KC server, that can be now used to authorize further calls to the remote endpoints. For exmple, if you want to check the internal jBPM repositories:

curl -H "Authorization: bearer $TOKEN" http://localhost:8080/kie-wb-6.4.0.Final/rest/repositories

12. Workbench High Availability

12.1. VFS clustering

The VFS repositories (usually git repositories) stores all the assets (such as rules, decision tables, process definitions, forms, etc). If that VFS resides on each local server, then it must be kept in sync between all servers of a cluster.

Use Apache Zookeeper and Apache Helix to accomplish this. Zookeeper glues all the parts together. Helix is the cluster management component that registers all cluster details (nodes, resources and the cluster itself). Uberfire (on top of which Workbench is build) uses those 2 components to provide VFS clustering.

To create a VFS cluster:

  1. Download Apache Zookeeper and Apache Helix.

  2. Install both:

    1. Unzip Zookeeper into a directory ($ZOOKEEPER_HOME).

    2. In $ZOOKEEPER_HOME, copy zoo_sample.conf to zoo.conf

    3. Edit zoo.conf. Adjust the settings if needed. Usually only these 2 properties are relevant:

      # the directory where the snapshot is stored.
      dataDir=/tmp/zookeeper
      # the port at which the clients will connect
      clientPort=2181
    4. Unzip Helix into a directory ($HELIX_HOME).

  3. Configure the cluster in Zookeeper:

    1. Go to its bin directory:

      $ cd $ZOOKEEPER_HOME/bin
    2. Start the Zookeeper server:

      $ sudo ./zkServer.sh start

      If the server fails to start, verify that the dataDir (as specified in zoo.conf) is accessible.

    3. To review Zookeeper’s activities, open zookeeper.out:

      $ cat $ZOOKEEPER_HOME/bin/zookeeper.out
  4. Configure the cluster in Helix:

    1. Go to its bin directory:

      $ cd $HELIX_HOME/bin
    2. Create the cluster:

      $ ./helix-admin.sh --zkSvr localhost:2181 --addCluster kie-cluster

      The zkSvr value must match the used Zookeeper server. The cluster name (kie-cluster) can be changed as needed.

    3. Add nodes to the cluster:

      # Node 1
      $ ./helix-admin.sh --zkSvr localhost:2181 --addNode kie-cluster nodeOne:12345
      # Node 2
      $ ./helix-admin.sh --zkSvr localhost:2181 --addNode kie-cluster nodeTwo:12346
      ...

      Usually the number of nodes a in cluster equal the number of application servers in the cluster. The node names (nodeOne:12345 , …​) can be changed as needed.

      nodeOne:12345 is the unique identifier of the node, which will be referenced later on when configuring application servers. It is not a host and port number, but instead it is used to uniquely identify the logical node.

    4. Add resources to the cluster:

      $ ./helix-admin.sh --zkSvr localhost:2181 --addResource kie-cluster vfs-repo 1 LeaderStandby AUTO_REBALANCE

      The resource name (vfs-repo) can be changed as needed.

    5. Rebalance the cluster to initialize it:

      $ ./helix-admin.sh --zkSvr localhost:2181 --rebalance kie-cluster vfs-repo 2
    6. Start the Helix controller to manage the cluster:

      $  ./run-helix-controller.sh --zkSvr localhost:2181 --cluster kie-cluster 2>&1 > /tmp/controller.log &
  5. Configure the security domain correctly on the application server. For example on WildFly and JBoss EAP:

    1. Edit the file $JBOSS_HOME/domain/configuration/domain.xml.

      For simplicity sake, presume we use the default domain configuration which uses the profile full that defines two server nodes as part of main-server-group.

    2. Locate the profile full and add a new security domain by copying the other security domain already defined there by default:

      <security-domain name="kie-ide" cache-type="default">
          <authentication>
               <login-module code="Remoting" flag="optional">
                   <module-option name="password-stacking" value="useFirstPass"/>
               </login-module>
               <login-module code="RealmDirect" flag="required">
                   <module-option name="password-stacking" value="useFirstPass"/>
               </login-module>
          </authentication>
      </security-domain>

      The security-domain name is a magic value.

  6. Configure the system properties for the cluster on the application server. For example on WildFly and JBoss EAP:

    1. Edit the file $JBOSS_HOME/domain/configuration/host.xml.

    2. Locate the XML elements server that belong to the main-server-group and add the necessary system property.

      For example for nodeOne:

      <system-properties>
        <property name="jboss.node.name" value="nodeOne" boot-time="false"/>
        <property name="org.uberfire.nio.git.dir" value="/tmp/kie/nodeone" boot-time="false"/>
        <property name="org.uberfire.metadata.index.dir" value="/tmp/kie/nodeone" boot-time="false"/>
        <property name="org.uberfire.cluster.id" value="kie-cluster" boot-time="false"/>
        <property name="org.uberfire.cluster.zk" value="localhost:2181" boot-time="false"/>
        <property name="org.uberfire.cluster.local.id" value="nodeOne_12345" boot-time="false"/>
        <property name="org.uberfire.cluster.vfs.lock" value="vfs-repo" boot-time="false"/>
        <!-- If you're running both nodes on the same machine: -->
        <property name="org.uberfire.nio.git.daemon.port" value="9418" boot-time="false"/>
      </system-properties>

      And for nodeTwo:

      <system-properties>
        <property name="jboss.node.name" value="nodeTwo" boot-time="false"/>
        <property name="org.uberfire.nio.git.dir" value="/tmp/kie/nodetwo" boot-time="false"/>
        <property name="org.uberfire.metadata.index.dir" value="/tmp/kie/nodetwo" boot-time="false"/>
        <property name="org.uberfire.cluster.id" value="kie-cluster" boot-time="false"/>
        <property name="org.uberfire.cluster.zk" value="localhost:2181" boot-time="false"/>
        <property name="org.uberfire.cluster.local.id" value="nodeTwo_12346" boot-time="false"/>
        <property name="org.uberfire.cluster.vfs.lock" value="vfs-repo" boot-time="false"/>
        <!-- If you're running both nodes on the same machine: -->
        <property name="org.uberfire.nio.git.daemon.port" value="9419" boot-time="false"/>
      </system-properties>

      Make sure the cluster, node and resource names match those configured in Helix.

12.2. jBPM clustering

In addition to the information above, jBPM clustering requires additional configuration. See this blog post to configure the database etc correctly.

13. Designer

Designer is a graphical web-based BPMN2 editor. It allows users to model and simulate executable BPMN2 processes. The main goal of Designe is to provide intuitive means to both technical and non-technical users to quickly create their executable business processes. This chapter intends to describe all feature Designer offers currently.

designer overview1
Figure 143. Designer

Designer targets the following business process modelling scenarios:

  • View and/or edit existing BPMN2 processes: Designer allows you to open existing BPMN2 processes (for example created using the BPMN2 Eclipse editor or any other tooling that exports BPMN2 XML).

  • Create fully executable BPMN2 processes: A user can create a new BPMN2 process in the Designer and use the editing capabilities (drag and drop and filling in properties in the properties panel) to fill in the details. This for example allows business users to create complete business processes all inside a a browser. The integration with Drools Guvnor allows for your business processes as wells as other business assets such as business rules, process forms/images, etc. to be stored and versioned inside a content repository.

  • View and/or edit Human Task forms during process modelling (using the in-line form editor or the Form Modeller).

  • Simulate your business process models. Busines Process Simulation is based on the BPSIM 1.0 specification.

Designer supports all BPMN2 elements that are also supported by jBPM as well as all jBPM-specific BPMN2 extension elements and attributes.

13.1. Designer UI Explained

Designer UI is composed of a number of sections as shown below:

designer ui parts
Figure 144. Designer sections
  • (1) Modelling Canvas - this is your process drawing board. After dropping different shapes onto the canvas, you can move them around, connect them, etc. Clicking on a shape on the canvas allows you to set its properties in the expandable Properties Window (3) (as well as create connecting shapes and morph the shape into other shapes).

  • (2) Toolbar - the toolbar contains a vast number of functions offered by Designer (described later). These includes operations that can be performed on shapes present on the Canvas. Individual operations are disabled or enabled depending on what is selected. For example, if no shapes are selected, the Cut/Paste/Delete operations are disabled, and become enabled once you select a shape. Hovering over the icons in the Toolbar displays the description text of the operation.

  • (3) Properties Panel - this expandable section on the right side of Designer allows you to set both process and shape properties. It is divided into four sections, namely "Core properties", "Extra Properties, "Graphical Settings" and "Simulation Properties". After clicking on a shape in the Canvas, this panel is reloaded to show properties specific to that shape type. If you click on the canvas itself (not on a shape) the panel displays general process properties.

  • (4) Object Library Panel - the expandable section on the left side of Designer shows the jBPM BPMN2 (default) shape repository tree. It includes all shapes of the jBPM BPMN2 stencil set which can be used to assemble your processes. If you expand each section sub-group you can see the BPMN2 elements that can be placed onto the Designer Canvas (1) by dragging and dropping the shape onto it.

  • (5) View Tabs - currently Designer offers three tabs for Process Modelling, Simulation and Documentation. Process Modelling is the default tab. When users run process simulation, its results are presented in the Simulation tab. Process Documentation tab displays documentation generated from process definition.

  • (6) Info Tabs - there are two additional tabs at the top of Designer. The Editor tab includes the process modeling while the Overview tab displays the process metadata such as version history, creation date, last modification date etc.

13.2. Getting started with Modelling

The Object Library panel provide means for users to select and drag/drop BPMN2 shapes onto the modelling canvas. Shapes are divided into sections as shown below:

object repository
Figure 145. Object Library

Once a shape is dropped onto the canvas users have a much faster way of continuing modelling without having to go back to the Object Library panel. This is realized through the shape morphing menu which is presented when a shape on the drawing canvas is clicked on. This menu allows users to either select a connecting shape (next shape) or morph the selected node into another node type. In addition this menu includes means to store the shape name as a dictionary item (explained later), view the specific BPMN2 code of the selected shape, as well as create/edit the task form (in the case of user tasks only).

morph menu
Figure 146. Morphing Menu for shapes

When connecting shapes Designer applies connection rules that follow the BPMN2 specification. The connection shapes presented in the morphing menu only show shapes that are allowed to be connections. Similarly same rules are applied when dropping a shape from the Object Library from the canvas and trying to connect an existing shape to it. Additional connection rules for boundary events are also available (explained later) and applied when for example moving an intermediate event node onto the edge of a task node.

Users can give names to every shape on the drawing canvas. This is done by double-clicking onto the shape as shown below.

naming shapes
Figure 147. Naming a shape

The name of a shape can be pulled from the Process Dictionary. If terms are set up in the dictionary, auto-complete can be used for the node names:

name autocomplete
Figure 148. Name auto-completion from dictionary

Designer also shows five buttons on top of a clicked shape as shown below.

node extra options
Figure 149. Extra in-line options

These include: * (1) Show in process Documentation - scrolls to the section of Process Documentation tab that corresponds to the shape clicked * (2) Add To Dictionary - allows users to add the name of the task to the Process Dictionary (explained in more details later) * (3) Edit Task Form - allows users to create/edit the Task Form. This option is only available for User Tasks * (4) Edit Data I/O - opens dialog for editting data input / output assignments for given node * (5) View Node Source - shows the BPMN2 for this particular shape only

The section should get you started with creating simple business process models by dragging/dropping BPMN2 shapes onto the drawing canvas. Next sections will dive deeper into many other aspects of Designer.

13.3. Designer Toolbar

The Designer toolbar contains many different functions which can be used during process modelling.

navbar1
Figure 150. Toolbar Buttons

We will now go through each of the buttons in the Designer Toolbar and give a brief overview of what it does.

(1) Save - allows users to save, copy, rename and delete the business process model. In addition users can turn on auto-save which will automatically save the business process within a defined time interval.

navbar save
Figure 151. Save Button

(2) Cut - enabled when a portion of the model is selected.

(3) Copy - enabled when a portion of the model is selected.

(4) Paste - paste the copied portion of the model onto the drawing board.

(5) Delete - enabled when there is a portion of the model is selected and removes it.

(6, 7) Undo/Redo - undo the last performed operation on the drawing canvas.

(8) Local History - local history allows continuous storage of your business process onto your browsers internal storage. Stored version of the business process can persist internet outages or browser crashes so your work will not be lost. This feature is disabled by default and must be enabled by users. Once local history has been enabled users are able to view all previously stored snapshots of their business model, clear local history, configure the snapshot interval, or disable local history. Note that local history will only take a snapshot of your business process on the set storing interval if there were some changes done in the model. If at the end of the snapshot interval Designer detects that there were no changes since the last local history save, no new snapshot will be created.

localhistory1
Figure 152. Local History

The Local History results screen allows users to select a stored snapshot of the model, view its process image and restore it back onto their drawing board.

localhistory results
Figure 153. Local History Sample Results

(9) Object positioning - allows users to position one or more nodes in the business process. Note that at last one shape must be selected first, otherwise these options are disable. Contains options "Bring to Front", "Bring to back", "Bring forward" and "Bring Backward".

(10) Alignment: enabled when a portion of the model is selected. Includes options "Align Bottom", "Align Middle", "Align Top", "Align Left", "Align Center", "Align Right" and "Align Same Size".

(11, 12) Group and Ungroup - allows grouping and ungrouping of selected shapes on the drawing board.

(13, 14) Locking and Unlocking - allows parts of the business model to be locked and unlocked. Locked parts of the model cannot be edited (visual display and properties are both locked). Locked nodes are displayed in a light blue color. This feature fosters collaboration of process modelling by allowing users to set parts of their model as "completed" and preventing any further changes to that portion. Other parts of the model can continue to be edited.

locked nodes
Figure 154. Locked Nodes

(15, 16) Add/Remove Docker - this allows users to add or remove Dockers, or edge points, to sequence flows in the model. Enabled when a sequence flow (connector) is selected. It allows users to create very customized connection points from one shape to another. Users can add and remove as many dockers as they would like on a single sequence flow.

adding dockers
Figure 155. Adding dockers to a sequence flow

(17) Color Themes - Colors are a big part or process modelling as they help with expressing intent as well as help allowing visually impaired users to better view the model. Designer provides two default color themes out of the box named "jBPM" and "High Contrast". The jBPM theme is the default theme used for all new business processes created. Users can switch color themes and the changes will be applied to all nodes that are currently on the model, as well as any new shapes added. Users have the ability to add new custom color themes by adding their own definitions in the Designer themes.json file. Color theme selection is persisted over browser close or possible crash/internet loss.

color themes
Figure 156. Color Themes selection
color themes2
Figure 157. Switching to High Contrast Color Theme

(18) Process and Task forms - here users have the ability to generate/edit process and task forms. When no user task is selected the default enabled options are "Edit Process Form" and "Generate all Forms". Generate all forms will apply the current model information such as process variables, data objects, and the user tasks data input/output parameters and associations to generate default executable input forms. Upon editing a process and task form, users have the choice between two form editors, the jBPM Form Modeler, and the Designer in-line meta editor. The Designer meta editor is targeted more to technical users as it is text based with the ability for live preview. When the user selects an user task in the model, the "Edit Task Form" and "Generate Task Form" options are enabled which allow users to edit the particular task form, or choose to apply the same generation logic to create a task form for the selected task only. Users have the ability to extend the default form generation templates in designer to create fully customized templates. Node that in the case of the Designer meta editor for forms, generating forms will overwrite existing forms for the process and user tasks. In the case of Form Modeler form generation, a merging algorithm is applied when generating.

forms1
Figure 158. Form generation selection

When selecting a task, users have the ability to edit the selected tasks form via the form button shown above the user task node.

forms2
Figure 159. In-line task editing

When editing forms, users are asked to choose between the Form Modeler and the Designer in-line meta editor. If the user selects Form Modeler the form is shown in a new asset tab separately from Designer. Designer meta editor is in-line and part of the Designer application.

forms3
Figure 160. Form Editor Selection

The Designer in-line meta form editor is a powerful text-based editor with a live preview feature as well as auto-completion on process variables and user task data inputs/outputs.

forms4
Figure 161. Designer in-line form meta editor with live-preview

(19) Process Information Sharing - this section includes many functions that help with sharing information of your model. These include:

  • Share process image - generates a stand-alone HTML image tag which contains a Base64 encoded image source of the current model on the canvas. This link can be shared to team members or other parties and embedded in any HTML content or email that allows HTML content embedding.

  • Share process PDF - generates a stand-alone HTML object tag which contains a Base64 encoded PDF source of the current model on the canvas. This can similarly be shared and embedded in any HTML content.

  • Download process PNG - generates a PNG image of the current process on the drawing board which users can download and share.

  • Download process PDF - generates a PDF of the current process on the drawing board which can be downloaded and shared.

  • View Process Sources - displays the current process sources in various formats, namely BPMN2, JSON, SVG, and ERDF. Also has the option to download the BPMN2 sources.

processsources
Figure 162. Process Sources View

(20) Extra tooling - this section allows users to import their existing BPMN2 processes into designer as well as be able to migrate their old jPDL based processes to BPMN2. For BPMN2 or JSON imports users can choose to add the import on top of the existing model on the drawing board or choose to replace the current one with the import.

extra1
Figure 163. Extra tooling section
extra2
Figure 164. Import existing BPMN2 panel
extra3
Figure 165. Process Migration panel

(21) Visual Validation - Designer includes over 100 validation checks and this list is growing. It allows users to view validation issues in real-time as they are modelling their business process. Users can enable visual validation, disable it, as well as view all validation issues at once. If Visual Validation is turned on, Designer with set the shape border of shapes that do not pass validation to red color. Users can then click on that particular shape to view the validation issues for that particular shape only. Alternatively "View All Issues" present a combined list of all validation errors currently found. Note that you do not have to periodically save your business process in order for validation to update. It will do so on its own short intervals during modelling. Users can extend the list of validation issues to include their own types of validation on certain elements of their business model.

validation1
Figure 166. Visual Validation Toolbar
validation2
Figure 167. Shapes with validation errors displayed with red border
validation3
Figure 168. Single shape validation issues display
validation4
Figure 169. View all issues validation display

(22) Process Simulation - Business Process Simulation deals with statistical analysis of process models over time. It’s main goals include

  • Pre-execution and post-execution optimization

  • Reducing the risk of change in business processes

  • Predict business process performance

  • Foster continuous improvements of performance, quality and resource utilization of business processes

Designer includes a powerful simulation engine which is based on jBPM and Drools and a graphical user interface to view and interpret simulation results. In addition users are able to view all process paths included in their current model on the drawing board. Designer Process Simulation is based on the BPSim 1.0 specification. Details of Process Simulation capabilities in Designer are can be found in its Simulation documentation chapter. Here we just give a brief overview of all features it contains.

sim1
Figure 170. Simulation tooling section

When selecting Process Paths, the simulation engine find all possible paths in the business model. Users can choose certain found paths and choose to display them. The chosen path is marked with given colors as shown below.

sim2
Figure 171. View all issues validation display

When selecting "Run Simulation", users have to enter in simulation runtime properties. These include the number of instances of this business process to simulate and the interval time and units. This interval is the time in-between consecutive simulation.

sim3
Figure 172. Simulation runtime properties

Each shape on the drawing board includes Simulation properties (properties panel) where users can set numerous simulation properties for that particular shape. More info on each of these properties can be found in the Simulation chapter of the documentation. Designer pre-sets some defaults for new processes, which allows business processes to be simulated by default without any modifications of these properties. Note however that the results of the default settings may not be optimal or targeted for the users particular needs.

sim4
Figure 173. Simulation properties for shapes

Once the simulation runtime has completed, users are shown the simulation results in the "Simulation Results" tab of Designer. The results default to the process results. Users can switch to results for each particular shape in their business process to see more specific detauls. In addition, the results contain process paths simulation results for each path in the business process.

sim5
Figure 174. Sample simulation results

Designer simulation presents the users with many different chart types. These include:

  • Process results: Execution times, Activity instances, Total cost

  • Human Task results: Execution times, Resource Utilization, Resource Cost

  • All other nodes: Execution times

  • Process Paths: Path Execution The below image shows a number of possible chart types users can view after process simulation has completed.

sim6
Figure 175. Types of simulation results charts

In addition to the chart results, Designer simulation also offers a full timeline display that includes all details of what happened during simulation. This timeline allows users to navigate through each event that happened during process simulation and select a particular node to display results at that particular point in time.

sim7
Figure 176. Simulation timeline

The simulation timeline can be switched to the Model view. This view displays the process model with the currently selected node in the timeline highlighted. The highlighted node displays the simulation results at that particular point in time of the simulation.

sim8
Figure 177. Simulation timeline model view

Path execution results shows a chart displaying the chosen path as well as path instance execution details.

sim9
Figure 178. Path execution details

(23) Service Repository - Allows users to connect to a service repository via its URL and see the list of available services it provides. Each of the listed services can then be installed into the users project by clicking on the "wrench" icon next to each listed service. Installing a service does the following things:

  • Installs the service configuration (wid) into the users Workbench project. This can later be edited via the Workitem Definitions Editor.

  • Installs the service icon (defined in the service configuration) and if one does not exist a default one will be provided.

  • Installs the service maven dependencies into the project POM.

  • Installs the service default handler into the project Deployment Descriptor.

Users will be notified when the service is successfully installed. After the install users have to re-open the business process to be able to start using the installed services.

servicerepo
Figure 179. Service Repository installation view

(24) Full screen Mode - allows users to place the drawing board of Designer into full-screen mode. This can help with better visualizing larger business processes without having to scroll. Note that this feature is possible only if your browser has full screen mode capabilities. If it does not designer will show a message stating this to the user.

fullscreen
Figure 180. Full Screen Mode

(25) Process Dictionary - Designer Dictionary Editor allows users to create their own dictionary entries or harvest from process documentation or business requirement documents. Process Dictionary entries can be used as auto-completion for shape names. This will be expanded in the future versions to allow mapping of node patters to specific dictionary entries as well. Users can add entries to the dictionary in the Dictioanry Editor or from the selected shapes directly.

dictionary1
Figure 181. Process Dictionary entry screen
dictionary2
Figure 182. Addint to process dictionary from selected shape

(26, 27, 28, 29) Zooming - zooming allows users to zoom in/out of the model, zoom in/out back to the original setting as well as zoom the process model on the drawing board to fit the currently dimensions of the drawing board.

14. Forms

This chapter intends to describe in a simple ways all the steps required to create a process with human tasks, generate and modify the forms for these tasks and execute them. It will provide initial guidance to perform all initial steps, but it will not provide a full description of all available features.

Given that forms are going to be used in tasks, it’s possible to generate forms automatically from process variables and task definitions. These forms can be later be modified by using the form editor. In runtime, forms will receive data from process variables, display it to the user and capture his input, and then finally updating process variables again with the new values.

The following example will show all the steps to follow to create a form for the 'Create order' task in the process below.

1 img process
Figure 183. Process example

This form must look like the following in execution:

2 execution
Figure 184. Process example

14.1. Configure process and human tasks

To hold values capture by forms, process variables can be created. These variables can be of a simple type like 'String' or a complex type. These complex types can be defined by using the Data Modeler tool, or be just regular POJOs (Plain Java Objects) created with any Java IDE.

In this example, we define a variable 'po' of type 'org.jbpm.examples.purchases.PurchaseOrder', defined with the Data Modeler tool.

3 variable definition
Figure 185. Process variable definition

This variable is declared in the 'variables definition' property for the process.

After that, we must configure which variables are set as input parameters to the task, which ones will receive the response back from the form and establish the mappings. This is done by setting the 'DataInputSet', 'DataOutputSet' and 'Assignments' properties for any human task. See screenshots below for details.

4 input var
Figure 186. Data input variable definition
5 output var
Figure 187. Data output variable definition
6 mapping var
Figure 188. Variable mapping definition

14.2. Generate forms from task definitions

The Process Designer module provides some functionality to generate the forms automatically from task and variable definitions, as well as easily open the right form from the modeler.

This is done with the following menu option.

7 auto generation
Figure 189. Form automatic generation

You can also click on the icon on top of task to open the form directly.

8 form access
Figure 190. Access to form edition

Forms are related to tasks by following a naming convention. If a form with a name formName-taskform is defined in the same package as the process, then this form is used by the human task engine to display and capture information from user.

Also, if a form named ProcessId-task form is created, it will be used as the initial form when starting this process.

For example, for our process the following forms would be generated.

9 form access
Figure 191. Access to form edition

14.3. Edit forms

Once the forms have been generated, you can start editing them. There are several artifacts that are generated in the previous process, but also can be created manually.

14.3.1. Form generated description

When the form has been generated automatically, this tab contain the process variables as data origins. This allow bind form fields with them, this relation it’s linked creating data bindings.

A data binding define how task inputs will be mapped to form variables, and when the form is validated and submitted, how the values will update the task outputs.

10 databinding
Figure 192. Generated form

For example, for this process, the following bindings are generated. Notice that the identifiers are automatically generated. You can have as many data origins as required, and can use a different colour to identify it.

In automatic form generation, a data origin is created for each process variable. The generated form have a field for each data origin bindable item (view FieldTypes) and this automatic fields have the binding defined too.

When these fields are displayed in editor the color of the data origin is shown over the field to make easy view if the field is correctly bound and the data origin implied.

14.3.2. Customizing form

We can change the way the form is displayed to the user in the task list. Next, we will show different levels of customization that will allow change it

14.3.2.1. Moving fields

The fields may be placed in different regions of the form. To move a field the user can access the contextual menu of the field and select 'Move field'.

11 movefield
Figure 193. Move field option

This will display the different regions of the form where you can place it.

12 move areas
Figure 194. Destination areas to move the field

A field can be moved to the first or the last region with the contextual icons for that purpose.

14.3.2.2. Adding new fields

You can add fields to forms either by its origin or by selecting one type of form field.

Let’s see what has been created automatically for this purchase order form.

13 field types
Figure 195. Form properties have been added by default, but are not still configured
  • Add fields by origin: this tab allows you to add fields to the form based on the data origins defined. These fields will have the correct configuration on the "Input binding expression" and "Output binding expression" properties, so when the form is submitted, the fields values will be stored in the corresponding Data Origin.

    17 add fields origin
    Figure 196. Add field by origin
  • Add fields by type: this tab allows you to freely add fields to the form from the Field Types palette on the Form Modeler. These fields won’t be storing their values on any Data Origin until they have a correct configuration on the "Input binding expression" and "Output binding expression" properties.

    17 add fields type
    Figure 197. Add field by type

To see a complete list of the available field types go to Field types section.

Notice the data model 'po' of type 'org.jbpm.examples.purchases.PurchaseOrder' is composed of three properties.

  • Simple: property of type text (description). We will adjust the view settings.

  • Complex: property of type object (header).

  • Complex: property of type array of objects (lines)

Now all these properties had to be configured.

14.3.2.3. Field configuration

Each field can be configured to enhance performance in the form. There are a group of common properties, that we call ‘Generic field properties’ and a group of specific properties that depends on the field type.

Generic field properties

There are a group of properties that are common to all field types. We will detail them below:

Field type

Can change the field type to other compatible field types

Field Name

Will be used as identifier in formulas calculation

Label

The text that will be shown as field label

Error message

When something goes wrong with the field, like validations,.. this message will be displayed

Label ccs class

Allows enter a class css to apply in label visualization

Label css style

to enter directly the style to apply to the label.

Help text

The text introduced is displayed as alt attribute to help to the user in data introduction

Style class

Allows enter a class css to apply in field visualization

Css style

to enter directly the style to apply to the label.

Read Only

When this check is on, the field will be used only for read

Input binding expression

This expression defines the link between field and process task input variable. It will be used in runtime to set the field value with that task input variable data.

Output binding expression

This expression defines the link between field and process task output variable. It will be used in runtime to set that task output variable.

Specific field properties

Let’s explain the specific properties of each field type:

  • Short Text (java.lang.String)

    • Compatible field type: Long text, E-mail, Rich text

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Show HTML: indicates whether the contents of the field is interpreted as HTML in show mode.

      • Formula. to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Range value. A range formula allows you to let you specify the values that the user can select from an specific field. These expressions are described in Formula & expression section

      • Pattern. Allow introduce an expression to specify the validation of the field. In case that the field value introduced hasn’t match the expression, and error is thrown and the error message has to be shown.

      • Default Value formula. Expression to set the field default value.

  • Long Text (java.lang.String)

    • Compatible field type: Long text, E-mail, Rich text

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Height: The number or rows to show at text area.

      • Formula. to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Range value. A range formula allows you to let you specify the values that the user can select from an specific field. These expressions are described in Formula & expression section

      • Pattern. Allow introduce an expression to specify the validation of the field. In case that the field value introduced hasn’t match the expression, and error is thrown and the error message has to be shown.

      • Default Value formula. Expression to set the field default value.

  • Float (java.lang.Float)

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Formula. to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Range value. A range formula allows you to let you specify the values that the user can select from an specific field. These expressions are described in Formula & expression section

      • Pattern. Allow introduce an expression to specify how the Float value has to be displayed. The pattern allowed is show in section pattern in https://docs.oracle.com/javase/6/docs/api/java/text/DecimalFormat.html

      • Default Value formula. Expression to set the field default value.

  • Decimal (java.lang.Double)

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Formula. Used to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Range value. A range formula allows you to let you specify the values that the user can select from an specific field. These expressions are described in Formula & expression section.

      • Pattern. Allow introduce an expression to specify how the Double value has to be displayed. The pattern allowed is show in section pattern in https://docs.oracle.com/javase/6/docs/api/java/text/DecimalFormat.html

      • Default Value formula. Expression to set the field default value.

  • BigDecimal (java.math.BigDecimal)

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Formula. Used to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Range value. A range formula allows you to let you specify the values that the user can select from an specific field. These expressions are described in Formula & expression section.

      • Pattern. Allow introduce an expression to specify how the BigDecimal value has to be displayed. The pattern allowed is show in section pattern in https://docs.oracle.com/javase/6/docs/api/java/text/DecimalFormat.html

      • Default Value formula. Expression to set the field default value.

  • Big integer (java.math.BigInteger)

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Formula. Used to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Range value. A range formula allows you to let you specify the values that the user can select from an specific field. These expressions are described in Formula & expression section.

      • Default Value formula. Expression to set the field default value.

  • Short (java.lang.Short)

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Formula. Used to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Range value. A range formula allows you to let you specify the values that the user can select from an specific field. These expressions are described in Formula & expression section.

      • Default Value formula. Expression to set the field default value.

  • Integer (java.lang.Integer)

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Formula. Used to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Range value. A range formula allows you to let you specify the values that the user can select from an specific field. These expressions are described in Formula & expression section.

      • Default Value formula. Expression to set the field default value.

  • Long Integer (java.lang.Long)

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Formula. Used to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Range value. A range formula allows you to let you specify the values that the user can select from an specific field. These expressions are described in Formula & expression section.

      • Default Value formula. Expression to set the field default value.

  • E-mail (java.lang.String)

    • Compatible field type: Short text, Long text, Rich text

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Default Value formula. Expression to set the field default value.

  • Checkbox (java.lang.Boolean)

    • Specific properties

      • Required: Indicates if it’s mandatory to fill this field.

      • Default Value formula. Expression to set the field default value.

  • Rich text: (java.lang.String)

    • Compatible field type: Short text, Long text, E-mail

    • Specific properties

      • Size: input text length.

      • MaxLength: Maximum number of characters allowed.

      • Required: Indicates if it’s mandatory to fill this field.

      • Height: The number or rows to show at text area.

      • Default Value formula. Expression to set the field default value.

  • Timestamp (java.util.Date)

    • Compatible field type: Short date

    • Specific properties

      • Size: input text length.

      • Required: Indicates if it’s mandatory to fill this field.

      • Formula. to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Default Value formula. Expression to set the field default value.

  • Short date (java.util.Date)

    • Compatible field type: Timestamp

    • Specific properties

      • Size: input text length.

      • Required: Indicates if it’s mandatory to fill this field.

      • Formula. to enter expressions that will be evaluated to set the field value. These expressions are described in Formula & expression section.

      • Default Value formula. Expression to set the field default value.

  • Document (org.jbpm.document.Document)

    • Specific properties

      • Required: Indicates if it’s mandatory to fill this field.

  • Simple subform (Object)

    • For more details see sectionSimple Object (Subform field Type).

      Specific properties

      • Default form. Show the list of available forms to select what one will be displayed to show the object.

  • Multiple subform (Multiple Object)

    • For more details see sectionArrays of objects.( Multiple subform field Type).

      Specific properties

      • Default form. Show the list of available forms to select what one will be displayed to show the object when no other form is configured with an specific purpose.

      • Preview form. If a form is specified, it will be used to show the item details

      • Table form. If a form is specified, it will be used to show the table columns when the item list is showed

      • New item text. Text to show at New Item button

      • Add item text. Text to show at Add Item button

      • Cancel text. Text to show at Cancel button

      • Allow remove Items. If this check is selected, the form allow remove items in table view.

      • Allow edit items. If this check is selected, the form allow edit items in table view.

      • Allow preview items. If this check is selected, the form allow preview items in table view.

      • Hide creation button. Check to not show the creation button

      • Expanded. If is checked, when a new item is being added, the field display the table with the existing items and the creation form at same time

      • Allow data enter in table mode. Allow modify data in table view directly. = Complex Fields Configuration :imagesdir: ..

There are two types of complex fields: fields representing an object, and fields representing an object array.

Once the field is added to the form, either automatically or manually, it must be configured so that the form had to know how to display the objects that will contain in execution time.

Next we describe how can be the configuration process:

  • The first thing to do is define how the contained object will be displayed. This is done creating a form that represents the object.

  • In case of the object array, you can define a form to show in preview(edition), or to show when table is shown

Once the form to represent the object, the parent form has to be configured to use them in the parent Subform or Multiple subform.

Below we will describe how the setup would be:

Simple Object (Subform field Type)

One possible way of setting the value for an object property is by using an existing form, and embedding this form into the parent. This is called subform.

In this example, the Purchase Order header data is held in an object. Therefore, we must create a form to enter all the purchase order header data and link it from the parent task form.

We will follow the steps:

  1. Create new form.

    14 create form
    Figure 198. Create new form
  2. Create new data origin, selecting the type of the purchase order header.

    15 create databinding
    Figure 199. Create new data origin
    16 manage databinding
    Figure 200. Data origin
  3. Add fields by origin. All the properties are shown, and can be added to the form, either one by one or all of them at once.

    17 add fields origin
    Figure 201. Add fields by origin

    All the properties have been added to the form, and now we can edit each of them and move them around.

    18 fields added
    Figure 202. All data origin fields added
  4. Configure the fields and customize form.

  5. Once the form has been saved, open the initial parent form and set the field property 'Default form'.

    19 subfom conf
    Figure 203. Configure the parent form

This will insert the subform inside the parent form, and will be shown as below:

20 subform configured
Figure 204. Parent form visualization after subform configuration
Arrays of objects.( Multiple subform field Type)

Now, we want to be able to create, edit and remove purchase order lines, by displaying a table with all the values and being able to capture information through a form. This will be done as follows:

Create a form that will hold and capture the information for each line’s value (description, amount, unitPrice and total), following the same steps as above. This will be done as follows:

  1. Create new form.

    21 multiple form creation
    Figure 205. Create new form
  2. Create new data origin.

    22 multiple binding creation
    Figure 206. Create new data origin
  3. Add fields by origin. All the properties are shown, and can be added to the form, either one by one or all of them at once.

    23 multiple add fields
    Figure 207. Configure the parent form
  4. Customize form. Change display options to improve the form visualization

  5. Configure the fields. After creating the basic form structure, we can use a formula to calculate automatically the total field. This formulas and expressions are described in Formula & expression section.

    25 multiple field conf
    Figure 208. Configuring formulas
  6. Finally, we save the lines form and go back to the parent form and configure all the lines properties.

    26 multiple subform conf
    Figure 209. Configure the parent form

    = Formulas :imagesdir: ..

Form Modeler provides a Formula Engine that you can use to automatically calculate field values. That Formula engine supports Java and XPATH expressions to access the form fields values. Let’s see some examples.

  • Setting a Default value formula

    Imagine that you have a form that contains a date field “Creation date” that has to be set by default with the current date. To do that you should edit the field properties and set a Default value formula like:

    =new java.util.Date();
    27 default value formula
    Figure 210. Setting default value formula

    After setting a Default formula value on a field properties, when the form is rendered by the first time the field will have the specified value.

    28 creationDate
    Figure 211. Rendering field with default formula

    As you can see, you can use a default formula any expression that return a value supported for the field.

  • Setting a Formula

    The formula engine allows you to calculate formulas that depend on other Field values using XPATH expressions to refer to fields values like {a_field_nane}, standard operators (+, -, *, /, %…​) to operate with them or calls to Java Functions for more complex operations.

    To start let’s see how you can create a formula to calculate the line_total of a Purchase Order Line. Look at the image below and look at the formula on the line_total properties.

    29 formula
    Figure 212. Rendering field with default formula

    With this expression:

    ={line_unitPrice}*{line_amount}

    we’re forcing the Total of the line value to be the result of the the Unit price multiplied by the Amount, so when the user fills the Amount and Unit Price fields automatically the Total Amount field value is going to be calculated and filled with the operation result:

    30 result
    Figure 213. Rendering field with default formula result

    Is possible to create formulas to operate with values stored in subforms using expressions like

    ={a_field/a_subform_field}

    Look at the next image to see how it works:

    31 formula 2

    This form has a subform field called po_header that is showing a form with the fields header_creationDate, header_customer and header_project. We want the Description field on our parent form to show some information from the header. Look at the Description field properties formula.

    ="Customer: " + {po_header/header_customer} + " Project: " + {po_header/header_project}

    This formula returns a text when the fields header_customer and header_projects are filled on the child form, so from now the parent form will be filled like this:

    32 execution formula

    Ok, you’ve seen how to create formulas that access to a subform fields values, now we are going to see how to work with values stored in Multiple Subforms. Imagine that we have a Purchase Order Line form that contains a multiple subform of Purchase Order Lines, and we want to calculate the total amount of the lines created. Look at the image below and how the TOTAL field is configured.

    33 formula 3

    On the formula expression: ={sum(po_lines/line_total)} we are using the XPATH function sum() that is going to summarize the totals of all the lines. So after creating some Lines the form will look like this:

    34 result 2

    Note that the line_total child field corresponds with the field line_total field on then form selected as a Default Form selected on the Lines field configuration.

    On this sample we are using the sum() XPATH function to calculate the total of the Purchase Order, but XPATH provides a lot of possibilities to select values from a set of children and also a lot functions to summarize values (sum, count, avg…​). For more information about XPATH you can take a look at http://www.w3schools.com/xpath/

  • Setting a Range Formula

    A range formula allows you to let you specify the values that the user can select from an specific field, showing it like a select box. It can be used on all simple types except Dates and Checkboxes.

    To see how it works look the next image and look at the Review Status field configuration.

    35 range value
    Figure 214. Setting default value formula

    As you can see that field is being shown as a select box and it has a range formula that specifies the values like this:

    {approve,Approve order;reject,Reject order;modifications,Request Modifications}

    This expression is defining 3 duos of value/"text to show" separated with the character ‘,’ and each of this duos is separated from each other other with the ‘;’ character. So due this formula the resulting select box will show:

    Value stored in input Text shown on Select Box

    approve

    Approve order

    reject

    Reject order

    modifications

    Request Modifications

    = Customizing form layout :imagesdir: ..

When you need an extra customization level and have more control over the HTML that is displayed. The form modeler provides the ability to edit the HTML directly.

To use this functionality, the user have to specify that in the ‘Form properties’ tab, 'Custom form layout' option and save.

Now the form is displayed with the custom HTML. To access this HTML editing, we click on the icon 'Edit'

The HTML editor is displayed; the HTML code will define how the form has to be shown. In this editor the user can directly create the HTML i locate the fields and labels with the syntax described below:

$field{fieldName} for field identified fieldName

$label{fieldName} for field identified fieldName label

These expressions will be replaced by the field or label rendering when the form will be shown.

Form modeler also provides two ways to help in the form HTML creation.

  • 'Insert form elements'

    Two select: one for the fields and another for the labels. Clicking on that, the field or label text is added to HTML. These selects only show the form fields haven’t been added yet.

  • 'Generate template based on'

    This functionality generates the HTML using all fields (default, alignment fields or Not aligned) depending on the selected value and overwrite the HTML. :leveloffset: -1

14.3.3. Field types

There are three types of field types that you can use to model your form:

  • Simple types

    These field types are used to represent simple properties like texts, numeric, dates, etc. The supported Field types are:

    Table 26. Field types
    Name Description Java Type Default on generated forms

    Short Text

    Simple input to enter short texts.

    java.lang.String

    yes

    Long Text

    Text area to enter long text.

    java.lang.String

    no

    Rich Text

    HTMLEditor to enter formatted texts .

    java.lang.String

    no

    Email

    Simple input to enter short text with email pattern.

    java.lang.String

    no

    Float

    Input to enter short decimals.

    java.lang.Float

    yes

    Decimal

    Input to enter number with decimals.

    java.lang.Double

    yes

    BigDecimal

    Input to enter big decimal numbers.

    java.math.BigDecimal

    yes

    BigInteger

    Input to enter big integers.

    java.math.BigInteger

    yes

    Short

    Input to enter short integers

    java.lang.Short

    yes

    Integer

    Input to enter integers.

    java.lang.Integer

    yes

    Long Integer

    Input to enter long integers

    java.lang.Long

    yes

    Checkbox

    Checkbox to enter true/false values

    java.lang.Boolean

    yes

    Timestamp

    Input to enter date & time values

    java.util.Date

    yes

    Short Date

    Input to enter date values.

    java.util.Date

    no

    Document

    File input to upload documents.

    org.jbpm.document.Document

    yes

  • Complex types

    These field types are made to deal with properties that are Java Objects instead of basic types. These field types need extra forms to be created in order to show and write values onto the specified Java Object/s

    Table 27. Complex types
    Name Description Java Type Default on generated forms

    Simple subform

    Renders the a form, it is used to deal with 1:1 relationships.

    java.lang.Object

    yes

    Multiple subform

    This field type is used to deal with 1:N relationships. It allows to create, edit and delete a set child Objects.Text area to enter long text.

    java.util.List

    yes

  • Decorators

    Decorators are a type of field types that don’t store data in the Object shown on the form. They can be used with aesthetic purpose

    Table 28. Decorators
    Name Description

    HTML label

    Allows the user to  create HTML code that will be rendered in the form

    Separator

    Renders an HTML separator

14.3.3.1. Custom Field Types

Is possible to extend the platform to add Custom Field Types that make a specific field (of any type) on the form to look and behave totally different than the standard platform fields. On this section we will take a look on how to create them and how to configure them.

How to create Custom Field Types

Basically a Custom Field Type is a Java class that implements the org.jbpm.formModeler.core.fieldTypes.CustomFieldType interface and is packaged inside inside a JAR file that is placed on the Application Server classpath or inside the application WAR.

Lets take a look atorg.jbpm.formModeler.core.fieldTypes.CustomFieldType:

package org.jbpm.formModeler.core.fieldTypes;

import java.util.Locale;
import java.util.Map;

/**
* Definition interface for custom fields
*/
public interface CustomFieldType {
    /**
    * This method returns a text definition for the custom type. This text will be shown
    * on the UI to identify the CustomFieldType
    * @param locale The current user locale
    * @return A String that describes the field type on the specified locale.
    */
    public String getDescription(Locale locale);

    /**
    * This method returns a string that contains the HTML code that will be used to show
    * the field value on screen
    * @param value The current field value
    * @param fieldName The field name
    * @param namespace The unique id for the rendered form, it should be used to generate
    * identifiers inside the HTML code.
    * @param required Determines if the field is required or not
    * @param readonly Determines if the field must be shown on read only mode
    * @param params A list of configuration params that can be set on the field
    * configuration screen
    * @return The HTML that will be used to show the field value
    */
    public String getShowHTML(Object value, String fieldName, String namespace,
              boolean required, boolean readonly, String... params);

    /**
    * This method returns a String that contains the HTML code that will show the input
    * view of the field. That will be used to set the field value.
    * @param value The current field value
    * @param fieldName The field name
    * @param namespace The unique id for the rendered form, it should be used to
    * generate identifiers inside the HTML code.
    * @param required Determines if the field is required or not
    * @param readonly Determines if the field must be shown on read only mode
    * @param params A list of configuration params that can be set on the field
    * configuration screen
    * @return The HTML code that will be used to show the input view of the field.
    */
    public String getInputHTML(Object value, String fieldName, String namespace,
              boolean required, boolean readonly, String... params);

    /**
    * This method is used to obtain the field value from the submitted values.
    * @param requestParameters A Map containing the request parameters for the
    * submitted form
    * @param requestFiles A Map containing the java.io.Files uploaded on the request
    * @param fieldName The field name
    * @param namespace The unique id for the rendered form, it should be used to generate
    * identifiers inside the HTML code.
    * @param previousValue The previous value of the current field
    * @param required Determines if the field is required or not
    * @param readonly Determines if the field must be shown on read only mode
    * @param params A list of configuration params that can be set on the field
    * configuration screen
    * @return The value of the field based on the submitted form values.
    */
    public Object getValue(Map requestParameters, Map requestFiles, String fieldName,
              String namespace, Object previousValue, boolean required, boolean readonly,
              String... params);
}

As you can see this Interface defines the methods that determines how the field has to be shown on the screen for when the form is shown on insert(getInputHTML(…​)) or readonly (getShowHTML(…​)) mode. It also provides the method (getValue(…​)) that reads the needed parameters from the request and to obtain the correct field value. Te returned value type must match with the type of the field added on the form.

Configuring and using Custom Field Types

Now let’s see how to use and configure and use a Custom Field type. Following the example on the previous chapter, we have created a File Input type and we have it already installed on our application. So now we are going to create a new form and add a Short Text property and turn it into a File Input and edit the field properties changing the Field Type from Short text toCustom field.

36 custom field types changing type
Figure 215. Changing a field type toCustom field

After changing the field type a new set of properties will appear:

37 custom field type properties
Figure 216. Custom field properties configuration form
Table 29. Custom field properties
Property Description

Field type

Can change the field type to other compatible field types

Field Name

Will be used as identifier in formulas calculation

Label

The text that will be shown as field label

Custom field

A list containing all the Custom Field Types available on the platform

First parameter

A String parameter that can be user to pass custom configuration needed by the Custom Field Type implementation

Second parameter

A String parameter that can be user to pass custom configuration needed by the Custom Field Type implementation

Third parameter

A String parameter that can be user to pass custom configuration needed by the Custom Field Type implementation

Fourth parameter

A String parameter that can be user to pass custom configuration needed by the Custom Field Type implementation

Fifth parameter

A String parameter that can be user to pass custom configuration needed by the Custom Field Type implementation

Required

Indicates if it’s mandatory to fill this field.

Read Only

When this check is on, the field will be used only for read

Input binding expression

This expression defines the link between field and process task input variable. It will be used in runtime to set the field value with that task input variable data.

Output binding expression

This expression defines the link between field and process task output variable. It will be used in runtime to set that task output variable.

So opening the Custom field select box we’ll be able to select the File Input from the available custom types:

38 custom field type select field
Figure 217. Available custom types

After selecting the File Input type on the list and saving the field properties the form will look like:

39 custom field type input file
Figure 218. Custom type display in a form

If we build a simple process and configure a Short text to be shown as the sampleFile Input, if we build the project on runtime the field will behave uploading the chosen files to the server and allowing the user to download it like this:

40 custom field type example running
Figure 219. Choosing the file to upload
41 custom field type example running 2
Figure 220. File uploaded, showing the download link

If we take a look at what’s the process variable value, we’ll see that is storing a String with the file path stored in server.

42 custom field type process value
Figure 221. Process variable storing custom type results

14.4. Document attachments

On this section we are going to describe step by step how to attach documents to your process variables from your forms and how you can configure to store the uploaded documents anywhere (File System, Data Base, Alfresco…​) using the Pluggable Variable Persistence.

14.4.1. Process and forms configuration

To make your process manage documents you have to define your process variables as usual using the Custom Type org.jbpm.document.Document. Each variable defined as Document will be shown on the form as a FILE input.

46 document variable
Figure 222. Defining a document variable

When the process forms are genereated and a org.jbpm.document.Document variable si found a File input will be placed on the form.

47 doc input
Figure 223. Form generated showing a org.jbpm.document.Document input

Each time a document is uploaded using a form the Form Engine will generate an instance of org.jbpm.document.Document to be stored on the process variable.

14.4.2. Marshalling strategy and deployment configuration

In order to store the document using the Pluggable Variable Persistence you’ll have to define your Marshalling Strategy to manage the uploaded Documents. To start create a Maven project with your favourite IDE and add the following dependencies:

<dependency>
  <groupId>org.kie</groupId>
  <artifactId>kie-api</artifactId>
  <version>{version}</version>
</dependency>
<dependency>
  <groupId>org.jbpm</groupId>
  <artifactId>jbpm-document</artifactId>
  <version>{version}</version>
</dependency>

Once you did that is time to create your Document Marshalling Strategy, to do so you just have to create a class that extends:

package org.jbpm.document.marshalling;

public abstract class AbstractDocumentMarshallingStrategy implements ObjectMarshallingStrategy {

  public abstract Document buildDocument( String name, long size, Date lastModified, Map<String, String> params );

  public void write( ObjectOutputStream os, Object object )
        throws IOException;

  public Object read( ObjectInputStream os )
        throws IOException, ClassNotFoundException;

  public byte[] marshal( Context context, ObjectOutputStream os, Object object )
        throws IOException;

  public Object unmarshal( Context context, ObjectInputStream is, byte[] object,
        ClassLoader classloader ) throws IOException, ClassNotFoundException;

  public Context createContext();
}

The methods to implement are:

  • Document buildDocument( String name, long size, Date lastModified, Map<String, String> params ): Creates a valid Document instance with the data received. This method is called when a document is uploaded to create the Document instance before marshalling the document content.

  • byte[] marshal( Context context, ObjectOutputStream os, Object object ): Marshals the given object and returns the marshalled object as byte[]

  • Object unmarshal( Context context, ObjectInputStream is, byte[] object, ClassLoader classloader ): Reads the object received as byte[] and returns the unmarshalled object

  • void write(ObjectOutputStream os, Object object): Implement for backguards compatibility, it should do the same functionallity than byte[] marshal( Context context, ObjectOutputStream os, Object object )

  • Object read(ObjectInputStream os): Implement for backguards compatibility, it should do the same functionallity than Object unmarshal( Context context, ObjectInputStream is, byte[] object, ClassLoader classloader )

You can see how the default DocumentMarshallingStrategy is implemented looking at this link.

After creating your Document Marshalling Strategy and add it to your server classpath the only thing remaining is to configure your project deployment descriptor add it to the marshalling strategies list. To do it you just have to open the Kie-Workbench on your browser, open your project on the Authoring view and edit the kie-deployment-descriptor.xml file located on <yourproject>/src/main/resources/META-INF and add your Document Marshalling Strategy to the <marshalling-strategies> list like this:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<deployment-descriptor
    xsi:schemaLocation="http://www.jboss.org/jbpm deployment-descriptor.xsd"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <persistence-unit>org.jbpm.domain</persistence-unit>
  <audit-persistence-unit>org.jbpm.domain</audit-persistence-unit>
  <audit-mode>JPA</audit-mode>
  <persistence-mode>JPA</persistence-mode>
  <runtime-strategy>SINGLETON</runtime-strategy>
  <marshalling-strategies>
    <marshalling-strategy>
      <resolver>reflection</resolver>
      <identifier>
        org.jbpm.document.marshalling.DocumentMarshallingStrategy
      </identifier>
    </marshalling-strategy>
  </marshalling-strategies>
  <event-listeners/>
  <task-event-listeners/>
  <globals/>
  <work-item-handlers/>
  <environment-entries/>
  <configurations/>
  <required-roles/>
</deployment-descriptor>

Since this is done you’re able to build your project and upload your documents on your process.

48 file input before
Figure 224. File input before file is uploaded
49 file input after
Figure 225. File input with an uploaded file

On this example we are configuring the default DocumentMarshallingStrategy, please use it for test and demo purposes.

14.5. Using forms on client applications

This chapter intends to describe how you can embed process forms and interact with them on another webapp including the new Javascript API provided by the platform.

You can find the library inside the kie-wb-*.war on the js file located on js/jbpm-forms-rest-integration.js.

14.5.1. What does the API provides?

This JavaScript API tries to be a simple mechanism to use forms on remote applications allowing to load the forms from different KIE Workbench instances, submit them, launch processes/tasks and execute callback functions when the actions are done.

The basic methods are:

showStartProcessForm(hostUrl, deploymentId, processId, divId, onsuccessCallback, onerrorCallback): Makes a call to the REST endpoint to obtain the form URL and if it gets a valid response will embed the process start form on the given div. The parameteres needed are:::

  • hostURL: the URL of the KIE Workbench instance that holds the deployments.

  • deploymentId: the deployment identifier that contains the process to run.

  • processId: the identifier of the process to run.

  • divId: the identifier of the div that has to contain the form.

  • onsuccessCallback (optional): a javascript function that will be executed if the form is going to be rendered. This function will receive the server response as a parameter

  • onerrorCallback (optional): a javascript function that will be executed if any error occurs and it is impossible to render the form. This function will receive the server response as a parameter

startProcess(divId, onsuccessCallback, onerrorCallback): Submits the form loaded on the given div and starts the process. The parameters needed are::

  • divId: the identifier of the div that to contains the form.

  • onsuccessCallback (optional): a javascript function that will be executed after the process is started. This function will receive the server response as a parameter

  • onerrorCallback (optional): a javascript function that will be executed if any error occurs and it is impossible to start the process. This function will receive the server response as a parameter

showTaskForm(hostUrl, taskId, divId, onsuccessCallback, onerrorCallback): Makes a call to the REST endpoint to obtain the form URL and if it gets a valid response will embed the task form on the given div. The parameteres needed are::

  • hostURL: the URL of the KIE Workbench instance that holds the deployments.

  • taskId: the identifier of the task to show the form.

  • divId: the identifier of the div that has to contain the form.

  • onsuccessCallback (optional): a javascript function that will be executed if the form is going to be rendered. This function will receive the server response as a parameter

  • onerrorCallback (optional): a javascript function that will be executed if any error occurs and it is impossible to render the form. This function will receive the server response as a parameter

claimTask(divId, onsuccessCallback, onerrorCallback): Claims the task whose form is being rendered::

  • divId: the identifier of the div that contains the form.

  • onsuccessCallback (optional): a javascript function that will be executed after the task is claimed. This function will receive the server response as a parameter

  • onerrorCallback (optional): a javascript function that will be executed if any error occurs and it is impossible to claim the task. This function will receive the server response as a parameter

startTask(divId, onsuccessCallback, onerrorCallback): Starts the task whose form is being rendered::

  • divId: the identifier of the div that contains the form.

  • onsuccessCallback (optional): a javascript function that will be executed after the task is started. This function will receive the server response as a parameter

  • onerrorCallback (optional): a javascript function that will be executed if any error occurs and it is impossible to start the task. This function will receive the server response as a parameter

releaseTask(divId, onsuccessCallback, onerrorCallback): Releases the task whose form is being rendered::

  • divId: the identifier of the div that contains the form.

  • onsuccessCallback (optional): a javascript function that will be executed after the task is released. This function will receive the server response as a parameter

  • onerrorCallback (optional): a javascript function that will be executed if any error occurs and it is impossible to release the task. This function will receive the server response as a parameter

saveTask(divId, onsuccessCallback, onerrorCallback): Submits the form and saves the state of the task whose form is being rendered::

  • divId: the identifier of the div that contains the form.

  • onsuccessCallback (optional): a javascript function that will be executed after the task is saved. This function will receive the server response as a parameter

  • onerrorCallback (optional): a javascript function that will be executed if any error occurs and it is impossible to save the task. This function will receive the server response as a parameter

completeTask(divId, onsuccessCallback, onerrorCallback): Submits the form and completes task whose form is being rendered::

  • divId: the identifier of the div that contains the form.

  • onsuccessCallback (optional): a javascript function that will be executed after the task is completed. This function will receive the server response as a parameter

  • onerrorCallback (optional): a javascript function that will be executed if any error occurs and it is impossible to complete the task. This function will receive the server response as a parameter

clearContainer(divId): Cleans the div content and the related data stored on the component.::

  • divId: the identifier of the div that contains the form.

14.5.2. Sample usage

Now let’s see an example how you can use the library to load the HR process form and start a new process instance. We are going to define a HTML page that will contain very simple components:

  • "Show Process Form" BUTTON: The button that is going to make a call to a showProcessForm() function to embedd the process form.

  • "myform" DIV: the div that will containt the form

  • "Start Process" BUTTON: the button that will call the startProcess() function that submits the form and start a new process instance. At the begining it will be hidden and only will be displayed when the form is going to be rendered.

First we are look at the HTML code:

<head>
  <script src="js/jbpm-forms-rest-integration.js"></script>
  <script>
      var formsAPI = new jBPMFormsAPI();
  </script>
</head>
<body>
  <input type="button" id="showformButton"
      value="Show Process Form" onclick="showProcessForm()">
  <p/>
  <div id="myform" style="border: solid black 1px; width: 500px; height: 200px;">
  </div>
  <p/>
  <input type="button" id="startprocessButton"
      style="display: none;" value="Start Process" onclick="startProcess()">
</body>

Notice that in first place we have added the js library and created an instance of the jBPMFormsAPI object that will manage the form rendering.

Now let’s see how the showProcessForm() function looks like:

function showProcessForm() {
  var onsuccessCallback = function(response) {
    document.getElementById("showformButton").style.display = "none";
    document.getElementById("startprocessButton").style.display = "block";
  }

  var onerrorCallback = function(errorMessage) {
    alert("Unable to load the form, something wrong happened: " + errorMessage);
    formsAPI.clearContainer("myform");
  }
  formsAPI.showStartProcessForm("http://localhost:8080/kie-wb/", "org.jbpm:HR:1.0", "hiring", "myform", onsuccessCallback, onerrorCallback);
}

As you can see, first we are defining the callback functions:

onsuccessCallback: This function is going to be called when the call to the REST endpoint and the form is going to be rendered. On this example we simply hide the "Show Process Form" button and show the "Start Process" button in order to allow to submit the form and start the process. This function takes as a parameter the response of the REST call to inform the user that everything gone well. ::

onerrorCallback: This function is going to be called if any error occurs (e.g. any communication error with the REST endpoint or unexpected js errors) On this example we simply show an alert showing the error message received and clear the "myform" DIV status. :: Once we defined the callback function we proceed to call the formsAPI.showStartProcessForm(…​) that is going make the REST call and embedd the form inside the specified div. Notice that we are providing a bunch of information in order to load the form, the URL where the KIE-Workbench is running (in this example "http://localhost:8080/kie-wb/"), the deployment where the process is located ("org.jbpm:HR:1.0"), the process id ("hiring"), the DIV id that is going to contain the form ("myform") and the callback functions (onsuccessCallback and onerrorCallback).

Now let’s take a look at the startProcess() that is the one that is going to submit the form and start the process:

function startProcess() {
  var onsuccessCallback = function(response) {
    document.getElementById("showformButton").style.display = "block";
    document.getElementById("startprocessButton").style.display = "none";
    formsAPI.clearContainer("myform");
    alert(response);
  }

  var onerrorCallback = function(response) {
    document.getElementById("showformButton").style.display = "block";
    document.getElementById("startprocessButton").style.display = "none";
    formsAPI.clearContainer("myform");
    alert("Unable to start the process, something wrong happened: " + response);
  }
  formsAPI.startProcess("myform", onsuccessCallback, onerrorCallback);
}

As showProcessForm(), first we are defining the callback functions. Both are doing basically the same:

  • Show the "Show Process Form" button and hide the "Start Process" button to allow start another process instance.

  • Clear the "myform" DIV status

  • Show an alert with the response notifying that the process has started well or if an error occured

Once that is done we just do the call to the formsAPI.startProcess(…​) that will send a message to the component that renders the form inside the "myform" DIV and will exectue the callback functions when the action is done. Notice that we don’t need the provide any other information than the DIV that contains the form and optionally the callback functions.

With a simple code like this you’ll be able to run process/task forms that are located on different Kie-Workbench instances from any other application.

43 embed form
Figure 226. Using forms on client applications I: Before showing the form
44 embed form
Figure 227. Using forms on client applications II: Showing the process form
45 embed form
Figure 228. Using forms on client applications III: After process started

15. Runtime Management

15.1. Deployments

In version 5.x processes were stored in so called packages produced by Guvnor and next downloaded by jbpm console for execution using KnowledgeAgent. Alternatively one could drop their process files (bpmn2 files) into a predefined directory that was scanned on the jbpm console start. That was it. That enforces users to always use Guvnor when dynamic deployment was needed. Although there is nothing wrong with it, actually that was recommended approach but not everytime it was desired.

Version 6, on the other hand moves away from proprietary packages in favor of, well known and mature, Apache Maven based packaging - known as knowledge archives - kjar. Processes, rules etc (aka business assets) are now part of a simple jar file built and managed by Maven. Along the business assets, java classes and other file types are stored in the jar file too. Moreover, as any other maven artifact, kjar can have defined dependencies on other artifacts including other kjars. What makes the kjar special when compared with regular jars is a single descriptor file kept inside META-INF directory of the kjar - kmodule.xml. That descriptor allows to define:

  • knowledge bases and their properties

  • knowledge sessions and their properties

  • work item handlers

  • event listeners

By default, this descriptor is empty (just kmodule root element) and is considered as marker file. Whenever a runtime component (such as jbpm console) is about to process kjar it looks up kmodule.xml to build its runtime representation. In addition to kmodule.xml a deployment descriptor (that provides fine graind control over deployment) is available (since 6.1).

15.1.1. Deployment descriptors

While kmodule is mainly targeting on knowledge base and knowledge session basic configuration, deployment descriptors are considered more technical configuration. Following are the items available for configuration via deployment descriptors:

  • persistence unit name for runtime data

  • persistence unit for audit data

  • persistence mode (JPA or NONE)

  • audit mode (JPA, JMS, NONE)

  • runtime strategy (SINGLETON, PER_REQUEST, PER_PROCESS_INSTANCE)

  • list of event listeners to be registered

  • list of task event listeners to be registered

  • list of work item handlers to be registered

  • list of globals to be registered

  • marshalling strategies to be registered (for pluggable variable persistence)

  • required roles to be granted access to resources of the kjar

  • additional configuration options of knowledge session

  • additional environment entries for knowledge session

  • list of fully qualified class names that shall be added to the classes used for serialization by remote services

  • whether or not to limit the classes from the deployment used for serialization by the remote services

Deployment descriptor is an xml file that is placed inside META-INF folder of the kjar, although it is an optional file and deployments will succeed even when such descriptor is missing.

<deployment-descriptor xsi:schemaLocation="http://www.jboss.org/jbpm deployment-descriptor.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <persistence-unit>org.jbpm.domain</persistence-unit>
    <audit-persistence-unit>org.jbpm.domain</audit-persistence-unit>
    <audit-mode>JPA</audit-mode>
    <persistence-mode>JPA</persistence-mode>
    <runtime-strategy>PER_PROCESS_INSTANCE</runtime-strategy>
    <marshalling-strategies/>
    <event-listeners/>
    <task-event-listeners/>
    <globals/>
    <work-item-handlers/>
    <environment-entries/>
    <configurations/>
    <required-roles/>
    <remoteable-classes/>
    <limit-serialization-classes/>
</deployment-descriptor>

It provides more configuration options then the standard deployment has. Deployment descriptors are used in hierarchical way meaning they can be placed on various levels of the system and merged on runtime. jBPM supports following levels of deployment descriptors:

  • server level - this is the main and considered default deployment descriptos that apply to all deployments on given server

  • kjar level - this is dedicated deployment descriptor to given kjar

  • deploy time level - this is deployment descriptor that is given at the time of deployment

Deployment descriptors on different levels are merged on deployment time where the master is considered descriptor lower in the hierarchy and slave one that is higher in hierarchy. To give an example, when a kjar is deployed and it contains deployment descriptor kjar’s deployment descriptor is considered slave and server level descriptor is considered master. With default merge mode it will override all master entries with slave ones as long as they are not empty and combine all collections.

Since kjar can have dependencies to other kjars, and in turn that dependencies might have deployment descriptors as well, they will be placed in deployment descriptors hierarchy lower than the actual kjar that is being deployed. With that said, this is how it will look like from hierarchy point of view, starting with master (server level):

  • server level

  • dependency kjar level

  • kjar level

That in default merging mode will result in deployment descriptor where with non empty values from kjar’s deployment descriptors and merged collection from all levels.

So far all merging was done with default mode, which is MERGE_COLLECTIONS but that’s not the only mode that is available:

  • KEEP_ALL - meaning that the master wins - all configuration defined in master will be retained

  • OVERRIDE_ALL - meaning that slave wins - all configuration defined in master will be retained

  • OVERRIDE_EMPTY - meaning all non empty configuration items from slave will replace those in master, including collections

  • MERGE_COLLECTIONS - meaning all non empty configuration items from slave will replace those in master but collections will me merged (combined)

Deployment descriptos can be given as partial xml documents, meaning they do not need to be complete set of all configuration items, e.g. if user would like to override only the audit mode in kjar, it’s enough to have following deployment descriptor:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<deployment-descriptor xsi:schemaLocation="http://www.jboss.org/jbpm deployment-descriptor.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <audit-mode>JPA</audit-mode>
</deployment-descriptor>

Although it’s worth noting that when using OVERRIDE_ALL merge mode all configuration items should be specified since it will always use them and do not merge with any other deployment descriptor in the hierarchy.

Default deployment descriptor

There is always default deployment descriptor available, even if it was not explicitly configured, when running in jbpm-console (kie-workbench) the default values are as follows:

  • persistence-unit is set to org.jbpm.domain

  • audit-persistence-unit is set to org.jbpm.domain

  • persistence-mode is set to JPA

  • audit-mode is set to JPA

  • runtime-strategy is set to SINGLETON

  • all collection based configuration items are left empty

Regardless of collection elements in default deployment descriptor are empty there will be some work item handlers/listeners registered that are required to support functionality of the jbpm console such as BAM listeners or human task work item handler.

Default deployment descriptor can be altered by specifying valid URL location to an xml file that will provide fully defined deployment descriptor. By fully defined we mean that all elements should be specified as this deployment descriptor will become server level deployment descriptor.

-Dorg.kie.deployment.desc.location=file:/my/custom/location/deployment-descriptor.xml

Collection configuration items

Deployment descriptor consists of collection based items (event listeners, work item handlers, globals, etc) that usually require definition of an object that should be created on runtime. There are two types of collection based configuration items:

  • object model - that is clear definition of the object to be built or looked up in available registry

  • named object model - that is an extension to object model and allows to provide name of the object which will be used to register object

Object model consits of:

  • identifier - defines main information about the object, such as fully qualified class name, spring bean id, mvel expression

  • parameters - optional parameters that should be used while creating object instance from the model

  • resolver - identifier of the resolver that will be used to create object instances from the model - (reflection, mvel, spring)

Table 30. Object models
Configuration item Type of collection items

event-listeners

ObjectModel

task-event-listeners

ObjectModel

marshalling-strategies

ObjectModel

work-item-handlers

NamedObjectModel

globals

NamedObjectModel

environment-entries

NamedObjectModel

configurations

NamedObjectModel

required-roles

String

Depending on resolver type, creation or look up of the object will be performed. The default (and easiest) is reflection that will use both parameters and identifier (in this case is FQCN) to construct the object. Parameters in this case can be String or another object model for representing other types than String. Following is an example of an object model that will create an instance of org.jbpm.test.CustomStrategy using reflection resolver that will use constructor of that class with two String parameters. Note that String paramaters are created with different ways (using object model - first param, directly by giving String - second param).

...
<marshalling-strategy>
  <resolver>reflection</resolver>
  <identifier>org.jbpm.test.CustomStrategy</identifier>
  <parameters>
    <parameter xsi:type="objectModel">
       <resolver>reflection</resolver>
       <identifier>java.lang.String</identifier>
       <parameters>
         <parameter xsi:type="xs:string" xmlns:xs="http://www.w3.org/2001/XMLSchema">param1</parameter>
       </parameters>
       </parameter>
         <parameter xsi:type="xs:string" xmlns:xs="http://www.w3.org/2001/XMLSchema">param2</parameter>
       </parameters>
</marshalling-strategy>
...

Same can be done by using DeploymentDescriptor fluent API:

// create instance of DeploymentDescriptor with default persistence unit name
DeploymentDescriptor descriptor = new DeploymentDescriptorImpl("org.jbpm.domain");

// get builder and modify the descriptor
descriptor.getBuilder()
.addMarshalingStrategy(new ObjectModel("org.jbpm.testCustomStrategy",
			new Object[]{
			new ObjectModel("java.lang.String", new Object[]{"param1"}),
			"param2"}));

Reflection based object model resolver is the most verbose in case there are parameters involved but there are few parameters that are available out of the box and do not need to be created, they are simply referenced by name:

  • entityManagerFactory (type of this parameter is javax.persistence.EntityManagerFactory)

  • runtimeManager (type of this parameter is org.kie.api.runtime.manager.RuntimeManager)

  • kieSession (type of this parameter is org.kie.api.KieServices)

  • taskService (type of this parameter is org.kie.api.task.TaskService)

  • executorService (type of this parameter is org.kie.internal.executor.api.ExecutorService)

So to be able to use one of these it’s enough to reference them by name and make sure that proper object type is used within your class:

...
<marshalling-strategy>
  <resolver>reflection</resolver>
  <identifier>org.jbpm.test.CustomStrategy</identifier>
  <parameters>
     <parameter xsi:type="xs:string" xmlns:xs="http://www.w3.org/2001/XMLSchema">runtimeManager</parameter>
   </parameters>
</marshalling-strategy>
...

In case reflection based resolver is not enough, more advanced resolver can be used that utilizes power of MVEL language. It’s much easier in the configuration as it expects mvel expression as identifier of the object model. It will provide the out of the box parameters (listed above: runtime manager, kie session, etc) into the mvel context while evaluating expression. To define object model with mvel resolver use following xml (that will be equivalent to replection based above):

...
<marshalling-strategy>
  <resolver>mvel</resolver>
  <identifier>new org.jbpm.test.CustomStrategy(runtimeManager)</identifier>
</marshalling-strategy>
...

Last but not least, there is Spring based resolver available as well that allows to simply look up a bean by its identifier from spring application context. This resolver is not used in jbpm console (kie-workbench) as it does not use spring but whenever jBPM is used together with Spring it might become handy when deploying kjars into the runtime. It’s very simple definition in xml, again equivalent to the other one assuming org.jbpm.test.CustomStrategy is registered in spring application context under customStrategy id.

...
<marshalling-strategy>
  <resolver>spring</resolver>
  <identifier>customStrategy</identifier>
</marshalling-strategy>
...

Manage deployment descriptor

Deployment descriptor is created as soon as project is created. It does contins the most basic deployment descriptor that is based on the default one. Meaning all settings present in default deployment descriptor will be copied into the one placed in the project. Further changes can be done directly in the xml content (in next versions more user friendly editor will most likely be provided). It is accessible from Administration perspecitve as this is considered technical administration task rather than business related activity.

edit deployment desc

Restrict access to runtime engine

jbpm console (kie-workbench) enables configuration of access restrictions to repositories (see Security management chapter for how this can be done). This protects repositories in the authoring perspective based on roles membership. Deployment descriptors moves this capability to the runtime engine by ensuring that access to processes will be granted only to users that belong to groups defined in the deployment descriptor as required roles. By default when project is created (at the same time deployment descriptor is created as well) required roles are automatically filled in based on repository restrictions. These roles can be still altered by editing deployment descriptor via Administration perspective as presented in Manage deployment descriptor section.

Security is enforced on two levels:

  • user interface - user will see only process definitions that are available for his/her roles

  • runtime manager - each access to get RuntimeEngine out of RuntimeManager is pretected based on the role membership, in case unauthorized access it attempted SecurityException will be thrown

Required roles are defined as simple strings that should match actual roles defined in security realm. Following is a xml snippet that shows definition of required roles in deployment descriptor:

<deployment-descriptor>
...
    <required-roles>
        <required-role>experts</required-role>
    </required-roles>
...
</deployment-descriptor>

In case fine grained control is required defined roles can be prefixed with one of the following to control it on further level:

  • view:

    to restrict access to be able to see given process definitions/instances on UI

  • executre:

    to restrict access to be able to execute given process definitions

  • all:

    applies to both view and execute restrictions and this is the default when no prefix is given.

For example to restrict access to show process from given kjar only to group 'management' but still allow them to be executed by anyone (sort of system processes) one could define it as follows:

<deployment-descriptor>
...
   <required-roles>
      <required-role>view:management</required-role>
   </required-roles>
...
</deployment-descriptor>

Classes used for serialization in the remote services

When processes make use of custom types (or in general non promitive types) and there is a use case to include remote api invocations (REST, SOAP, JMS) such types must be available to the remote services marshalling mechanism that is based on JAXB for XML type. By default all types defined in kjar will be automatically included in JAXB context and therefore will be avialble for remote interaction. Though there might be more classes (like from dependent model) that shall be included there too.

Upon deployment, jBPM will scan classpath of given kjar to automatically register classes that might be needed for remote interaction. This is done based on following rules:

  • all classes included in kjar project itself

  • all classes included as dependency of projects type kjar

  • classes that are annotated with @XmlRootElement (JAXB annotation) and included as regular dependency of the kjar

  • classes that are annotated with @Remotable (kie annotation) and included as regular dependency of the kjar

If that is not enough deployment descriptor allows to manually specify classes that shall be added to the JAXB context via remoteable-classes element:

<remoteable-classes>
   ...
   <remotable-class>org.jbpm.test.CustomClass</remotable-class>
   <remotable-class>org.jbpm.test.AnotherCustomClass</remotable-class>
   ...
</remoteable-classes>

With this all classes can be added to the JAXB context to properly marshal and unmarshal data types when interacting with jBPM remotely.

Limiting classes usd for serialization in the remote services

When there are classes in the kjar project or in the dependencies of the kjar project that woudl cause problems when used for serialization, the limit-serialization-classes property can be used to limit which classes are used for serialization

<limit-serialization-classes>true</limit-serialization-classes>

This property limits classes used for serialization to classes which fulfill both of the following "location" and "annotation" criteria:

Classes that:

  1. are located in the kjar project

  2. are in a direct dependency of the kjar project

  3. are listed in the remoteable-classes element and are available on the classpath of the kjar

These classes must also be annotated with one of the following type annotations:

  • javax.xml.bind.annotation.XmlRootElement

  • javax.xml.bind.annotation.XmlType

  • org.kie.api.remote.Remotable

Additionally, classes will be excluded if they are any of the following: interfaces, local classes, member classes or anonymous classes.

15.2. Process Deployments

You can access to the Process Deployments List under the Deploy top level menu of the KIE Workbench

process deployments

The Deployed Unit list shows all the Process Deployed Units into the platform that are already enabled to be used. Each deployment unit can contain multiple business processes and business rules. In order to have your process and rules deployed and listed in this list, you need ot Build and Deploy your KIE projects from the Authoring Perspective or via the Remote Endpoints. If your processes and rules are in a KIE Project listed in this list and you have correspondent the rights you should be able to see the process definitions in the Process Definitions Perspective.

deployed unit list

From the Authoring Perspective (Build and Deploy), a default deployment will be performed, for a more advanced deployments you can trigger a custom deployment with other options from this screen.

build and deploy

By clicking the New Deployment Unit (+) button you will be able to select a different KIE Base, KIE Session, Strategy and Merge Mode for your deployment. By default the "DEFAULT" KIE Base and KIE Sessions are used, the SINGLETON Strategy is selected and the Merge Mode is set to "Merge Collection".

new deployment

15.3. Jobs

The Jobs perspective allows you to monitor and trigger Asynchronous Jobs schedulled to the jBPM Executor Service. You can access to the Jobs List from the Deploy top level menu of the KIE Workbench.

jobs menu

The Jobs List shows all the Jobs that were schedulled and their status. The Filter on top of the table helps the administrator to monitor the Jobs execution and take corrective actions in case of Failure. Check the jBPM Executor section of the documentation for more information.

jobs actions

Administrators have also the option to configure the jBPM Executor Service Settings and to start and stop the service from the User Interface via the Actions → Settings option.

jobs service settings

Administrators can also schedulle manually new Jobs from the User Interface via the Actions → Settings option. By specifing the command class name and the parameters needed to run the command a new Job can be created. This manually created jobs will not be associated with any process instance. Notice also that the Due Date paramenter allows the execution to be derrefered for the future. If the Due Date is the time of schedulling the jBPM Executor Service will execute the command as soon as there is an Executor Thread available. The number of retries will help the command to be executed more than once if it fails. This can help in situations when the business logic requires an external service to be called where the runtime cannot rely on that service to be available 100% of the time.

jobs new

16. Process and Task Management

16.1. Process Management

This chapter describes the screens related with the creation and management of process definitions and process instances.

Once you have modelled, configured all the technical details and build and deployed your projects containing your business processes you should be able to see all the available process definitions in the Process Definition List. For all the process definitions listed in the Process Definitions List you will be able to inspect the Process Definition details and start as many Process Instances as needed. The following sections describes the features provided by all the screens in charge of the manipulation of process definitions and process instances. You can find these screens under the Process Management Menu, in the jBPM Console NG or in KIE Workbench.

You can find the source code related with the process definition and instances manupilation inside this module: http://github.com/kiegroup/jbpm-console-ng/tree/master/jbpm-console-ng-process-runtime Feel free to report issues, send Pull Requests and get in contact with the team via comments in github.

process management

16.1.1. Process Definitions

The process definition section is composed by two main screens: the Process Definition Lists and the Process Definition Details.

16.1.1.1. The Process Definition List

The process definition list shows all the available process definitions that were deployed into the platform. Look at the Deployments section for more information about how to check all the deploymed units available in the platform runtime.

process definitions list

You can click in the list rows to access to the details of the process definition.

16.1.1.2. The Process Definition Details

The process definition details shows all the available information about the process definition. You can consider this screen as a brief about the process model. You can quickly see if there is a Sub Process associated with it, or how many users and groups are participating in the selected definition.

process definitions details

Notice that you can View the Process Model (Read Only mode) using the Options Menu in the top bar. You can also look at all the process instances for the selected process definition by going to Options → View Process Instances.

process model
16.1.1.3. Creating Process Instances

You can create new Process Instances from the Process Definition List (Action Column), from the Process Definition Detail view or from the Process Instance.

process definitions new instance

When you create a Process Instance usually a Form will be presented to introduce the information required by the process to be started. Once you complete the required information and click on the Submit button, the instance will be created and the details of the Process Instance will be displayed on top of the Process Definition Details.

16.1.2. Process Instances

The process instances section is composed by two main screens: the Process Instance Lists and the Process Instance Details. In this case the Process Instance Details provides several tabs with the runtime information related with the process.

process instances list

Each row inside the process instance list represent a running process instance from a particular Process Definition. Each execution is differentiated from all the others by the internal state of the information that the process is manipulating. In order to inspect this information you can click in each row to see the process instance details.

process instances details

As you can see the Process Instance Detail first tab gives you a quick overview about what is going on inside the process. This is by showing the current state of the instance and also the current activity that is being executed. The process variables tab display all the process variables that are being manipulated by the instance with the exception of the variables that contains documents.

process instances variables

If the process contains a variable of the type: org.jbpm.Document it will be listed in the Documents tab, for easy access, download and manipulation of the attached documents. Notice that at this point you cannot attach new documents to currently running instances, but this feature will be added in future versions.

process instances documents

Finally, the Logs tab shows two types of logs for different end users. There are two types of Logs available inside the tab: Business and Technical.

process instances logs

To complement the process logs you can open the Process Model that shows the completed activies in grey and the current activities highlighted in red.

process instances running model
16.1.2.1. Process Instance List

This list works with the concept of view. A view is a set of visualization parameters that modify what items has to be displayed and how the items details has to be shown.

A view embrace

  • Columns to be shown

  • Items by page

  • Restrictions over the displayed process instances

  • A Name to be shown at tab name

  • A Description as title when the view is selected

We find here different areas with different purposes:Filtering, general section configuration and specific view parameter setting in the data grid presentation:

process instances areas
Filtering. Views on tabs

Here, there are the available views as tabs. When a tab is selected, the related parameters are applied to the data grid. Here we have include the Dataset technology for queries and its queries editor as a powerful tool to create the filters

The user can remove existing tabs clicking the cross button near the tab name

process instances remove tab

A new view can be created clicking the last tab, over the '+' button. A New Items list popup appears and lets the user introduce parameters related with the new tab like: the name, the description and the filter.

process instances create tab labels
process instances create tab filter 1

If the view has to include a restriction over a specific column, then the link 'Add new' has to be selected. A drop down list with all the columns to create restrictions

process instances create tab filter 2

Once the column is selected, depending of its type, a new dropdown list is open with the kind of restrictions available for the selected column and the necessary form to add them.

process instances create tab filter 3

One filter can include a list of different conditions over different columns and the editor allow remove each one clicking th 'x' button near them

Once the view creation parameters are defined, the 'Ok' button makes the new view appears as a new tab.

General section configuration. Auto refresh and default views restore

In this area, the user can create a new item (in this case process instance), can refresh manually the view that is being displayed, can configure autorefresh option and can restore default filters.

process instances generalarea

Auto refresh is a functionality that allows define how often the data grid has to be refresed. The user can select one of the different values ( 1,5 or 10 minutes),or disable this feature, clicking 'Disable'. If the auto refresh is enabled, then the last view displayed is refreshed after the amount of time defined.

The last button is the 'Restore default filters'. There is a set of predefined views that appears the first time the user access to the section, in the case of process instances list they are: Active, Complete and Aborted. The user can remove every view includind the default ones, but in this area the default views can be restored clicking 'Restore default filters'.

Specific view configuration. Columns, Bulk actions, number of items

In this area the user can change dynamically the view editable parameters like visible columns, or set the number of items to show in a page.

process instances column selector

Here we have the posibility or execute bulk actions over the items marked as selected. I this case the available actions are 'Abort' or 'Signal'

process instances specific area

The number of items to show in a page can be configurable too, from the page size dropdown list

process instances number items
Special filter in process instance list

There is an specific restriction than makes the process instance list view, have a different behaviour. This happend when a filter over the column 'PROCESSID' is defined.

In this case, the columns available to show have been incremented with the specified process variables which have value. The user can then, view process instance variables from a specific process id, in the same grid of the process instances.

process instances process id variables

16.2. Tasks

This chapter introduces the Task Management screens and the its integration with the Form Modeller component to allow users to work on their assigned tasks. You can find the source code of these screens here: https://github.com/kiegroup/jbpm-console-ng/tree/master/jbpm-console-ng-human-tasks . Feel free to report issues, send Pull Requests and get in contact with the team via comments in github. At the end of this section you will find a technical description about how to customize these views.

16.2.1. Task List

Every user with access to the platform will have access to its personal task list where tasks assigned to him/her will be displayed. Each user will be able to create its own personal tasks or work on tasks that were create as a result of a business process execution.

You can access to the Task List accessing Tasks main menu:

task menu
16.2.1.1. Task List (Personal and Group Tasks)

Pending tasks for each user will be displayed in their task list screen. Notice that you will not be able to see assigned tasks from another user different from the one that is currenlty logged in.

Task List

The list will show all the tasks that match with the defined restrictions ordered by the columns presented. You can change the default ordering clicking on the column header. This view offer a more traditional BPM Task List view where you can sort the data based on different columns.

task list

Here appears again the concept of view versus just filtering as we explained in the process instante list. The default views here have the following restrictions over the tasks to show:

  • Active: all the Active tasks that user can work on. That means Personal and Group Tasks.

  • Personal: all the personal tasks that already belong to the user.

  • Group: all the group tasks that needs to be claimed by the user in order to start working on them.

  • All: show all the tasks no matter the status. It will show completed tasks as well with the exception of completed tasks that belongs to a process that is already finished. In such cases the tasks are cleaned up after the process is completed and for that reason they will not be displayed.

  • Admin: show all the tasks where the currently logged user was set as business administrator for such task.

The user can always restore the default filters selecting the option 'Restore default filters'

Task List custom filters. Ability to show bussiness data at task list.

As was explained in the process instance list, the user can define custom filters adding new tab and defining restrictions over task data in this case.

The user can now create a specific filter that provides domain specific columns to be added to a task list. When the user creates a custom filter for a specific task name the task variables are enabled as columns.

task basic columns
Figure 229. Basic available columns that every task list allows select to be displayed.

The custom filter that activates the capability to display task variables as columns is set a filter with the restriction Name="taskName".

task filter taskname
Figure 230. Filter by task name creation

When the filter with the restriction over a specific task name is applied, the task associated variables appear as a selectable columns, to the task list.

task var as columns
Figure 231. task list with task name restriction applied
16.2.1.2. Task Details

You can access to the Task Details by clicking in a task row. The details associated with a task can be changed, like for example the Due Date, the Priority or the task description.

task details

The task details appear in a new region with different sections that allow view the task associated information:

Work In this tab the associated form is displayed if the task has one. In this section is where the user can interact with the process, executing the available actions in each moment.

Details Here the basic task data is accessible: priority, status, description

task details1

Process Context Data related with the process instance associated. If the task was created by a Business Process, you will have access to see the Process Instance status that has created it.

task process context

Assignments The Task Assignments tab allows you to delegate the task to another person or group if you are not able to continue working on it.

task assignments

Comments You can also add while you are working on a task comments about the progress.

task comments
16.2.1.3. Work on a Task

Tasks can have associated a Form to store data. If tasks are part of a Business Process, usually some data needs to be collected and propagated to the business process for further usage. For that reason, tasks has to provide a way to gather and store data. Forms can be created for specific tasks using the Form Modeller. If no form is provided a dynamic form will be created based on the information that the task needs to handle. If a task is created as an ad-hoc task (not related with any process) there will be no such information to generate a form and only basic actions will be provided.

task form
16.2.1.4. Task Forms generated by the Form Modeller

As part of your projects you can model your forms for your human tasks, providing a rich interface for collecting data. This shows the Form Modeller canvas while designing the previously Task Form.

task form modeller designed

16.2.2. New Task (Ad-Hoc Task)

As mentioned in the introduction a User can create their own tasks, which will not be associated with any Business Process. These tasks can be used to keep track of your personal list of TO DOs. You can also create tasks and assign them to different people in your team or group.

task new task

At the advanced tab the user can define information like priority or the task due on date.

task new task advanced

When a user creates a new task, can associate an existing form. At the 'Form' tab, the deployment id has to be selected from the list of available deployments id

task new task form deployment

In that moment, the next list of form names is filled with the available forms at that deployment.

task new task form selector

Once the 'Create' button has been selected, a task is created with the associated form and the status 'In Progress'. The complete action on task shows the selected form.

17. Business Activity Monitoring

17.1. Overview

Imagine you are developing a BPM solution which mixes process with business data. Imagine also you need some forms to be used within processes in order to let the users enter data. Moreover, you’ll likely want to have some kind of dashboards to display metrics and key performance indicators in order to quickly assess how your processes are doing. So far so good.

jBPM brings you all the ingredients you need to develop end-to-end business process solutions. The jBPM’s BAM module (also known as Dashbuilder) allows for composing custom business dashboards by mixing data coming from heterogeneous sources of information. The module is now fully integrated into KIE workbench. A new specific section for dealing with dashboards has been added and it can be accessed either from the home page or from the menu bar, as shown in the next figure.

KieWorkbenchBAMMenus
Figure 232. BAM menu options in the KIE Workbench home page

In the figure, within the highlighted sections, there exists two options:

  • Business Dashboards: This option is intended to give users access to a generic dashboard tooling for the composition of brand new dashboards.

  • Process & Task Dashboard: It opens up the Process Dashboard perspective which contains several performance indicators related to the jBPM execution engine.

17.2. Business Dashboards

BPM solutions are not only made up with processes, rules or forms but also with data belonging to the customer business domain. Such data is handled in the forms, the rules and, of course, the dashboards that are part of the solution. Usually, dashboards feed with data coming from several sources of information, from business domain entities persisted into relational databases to data hold in legacy systems. In order to cope with this kind of scenarios a generic highly customizable dashboard tooling is needed.

It’s obviously expected that a customer building a BPM solution want to track how its processes are performing. To do so the customer need a monitoring and reporting tool. This is the main reason why the Dashbuilder project has been included as a core module of the jBPM ecosystem. Notice also that Dashbuilder, as an independent project, is not only used by jBPM but also by many other projects like, for example, JBoss Teiid a data virtualization system that allows applications to use data from multiple, heterogeneous data stores.

The Business Dashboards gives users access to a rich enviroment where it is possible to author new content as well as configuring which entries are displayed in the top menu bar.

ContentManagementPerspective
Figure 233. Business Dashboards Perspective
THIS SECTION IS UNDER CONSTRUCTION

17.3. Process Dashboard

The jBPM Process Dashboard is an specific use case of a dashboard feed from data coming from a relational database via SQL queries. In this case, the database tables consumed are: processinstancelog and bamtasksummary both belonging to the jBPM engine.

Every time the jBPM runtime updates the information stored into such tables the data becomes automatically available to the dashboard indicators. The following picture shows the main screen that users get when navigating to the Process & Task Dashboard.

ProcessesDashboard
Figure 234. Processes dashboard

Notice, those are generic metrics not tied to any specific business process. Nonetheless, it’s worth to mention that it would be very easy for customers to modify, extend or adapt this generic dashboard for custom needs. A customer could take the jBPM Process Dashboard as the base template for building a custom dashboard which mixes data coming from the jBPM engine plus data coming from its own business domain.

As you can see there exists two tabs in the top of the screen: Processes and Tasks. As their name indicates, every tab contains only indicators related to either processes or tasks.

To filter through the data users can click on the charts in order to select, for instance, a given process, a given status, etc…​ Every time a filter is applied, all the indicators are automatically updated and synced according to the criteria set. The next picture shows, for instance, what happens when both the process Sales and the status Active are selected.

ProcessesDashboardFilter
Figure 235. Active Process Filter

Using the built-in filter features is a good way to select the process instances the users want to look into. Additionally, at any time, no matter whether there is any active filter or not, users can also navigate to the actual list of instances the dashboard indicators are showing. The Show Instances link at the top right side on the screen can be used to display those instances. Once clicked, the view is switched to the screen shown in the next picture:

ProcessesDashboardInstanceList
Figure 236. Process Instance List

From this view, users can sort the instances just by clicking on any column. They can get a detailed view of a particular instance just by clicking on the desired row as well.

ProcessesDashboardInstanceDetails
Figure 237. Process Instance Details

The process instance details panel is shown on the right of the screen just after clicking on a row. Notice this is a read only view, just for monitoring purposes. After identifying a target process instance the next step is to use the jBPM Process Instance Console in case the user needs to manage such process instance.

17.3.1. Task Dashboard

To switch from the process view to the task view just click on the Tasks tab at the top of the screen.

ProcessesDashboardInstanceDetails
Figure 238. Task Dashboard

The task view only contains indicators related to tasks. It basically provides the same features introduced above for process instances (filters, show instances, get details), this time related to tasks instead of processes though.

ProcessesDashboardInstanceDetails
Figure 239. Task Instance List
ProcessesDashboardInstanceDetails
Figure 240. Task Instance Details

To sum up, the jBPM Process & Task Dashboard let users:

  • To monitor their processes and tasks

  • To apply the proper filters in order quickly identify problematic instances

  • To get the required information about a given instance in order to be able to fix any unexpected issue

Eclipse

How to use the Eclipse-based tooling

18. jBPM Eclipse Plugin

18.1. jBPM Eclipse Plugin

The jBPM Eclipse plugin provides developers (and very technical users) with an environment to edit and test processes, and integrate it deeply with their applications. It provides the following features (on top of the Eclipse IDE):

  • Wizards for creation of

    • a jBPM project

    • a BPMN2 process

  • jBPM Perspective (showing the most commonly used views in a predefined layout)

18.1.1. Installation

The jBPM installer is capable of downloading and installing an Eclipse installation, including the Drools and jBPM Eclipse plugin (with a full jBPM runtime preconfigured) and the Eclipse BPMN2 Modeler.

Using the jBPM installer is definitely the recommended starting point for most users.

You can however also download and install the jBPM Eclipse Plugin manually. To do so, you need to:

  • Download Eclipse (Kepler recommended, but older versions like Indigo or Juno should also still work)

  • Start Eclipse

  • Select "Install New Software …​" from the Help menu. Add the Drools and jBPM update site http://downloads.jboss.org/jbpm/release/6.0.1.Final/updatesite/. You should see the plugins as shown below. Note that you can also download and unzip the Drools and jBPM update site to your local file system and use that as local update site instead.

    UpdateSite

    Select the JBoss jBPM Core and JBoss Drools Core plugins and click "Next >". Click "Next >" again after reviewing your selecting, accept the terms of the license agreement and click "Finish" to download and install the plugins. If you get a warning about installing software that contains unsigned content, click OK. After successful installation, Eclipse should ask you to restart, click Yes.

  • The plugin should now be installed. To check, check if you can for example see the new jBPM Project wizard: under the "File" menu, select "New Project …​" and there you should be able to see "New jBPM Project" under the jBPM category.

  • Register a jBPM runtime to get started, see the section on jBPM runtimes in this chapter for more information.

Note that, when doing a manual install, you still need to manually install the Eclipse BPMN 2.0 Modeler plugin as well. Check out the chapter on the Eclipse BPMN 2.0 Modeler on how to do that.

18.1.2. jBPM Project Wizard

The aim of the new project wizard is to set up an executable sample project to start using processes immediately. This will set up a basic structure, the classpath, sample process and a test case to get you started. To create a new jBPM project, in the "File" menu select "New" and then "Project …​" and under the jBPM category, select "jBPM Project". A dialog as shown below should pop up.

WizardProject

Fill in a name for your project and if necessary change the location where this project should be located (by default Eclipse will generate it inside your Eclipse workspace folder) and click "Next >".

Now you can optionally include a sample process in your project to get started. You can select to either use a simple "Hello World" process, a slightly more advanced process including human tasks and persistence or simply an empty project. You can also select to include a JUnit test class that you can use to test your process. These can serve as a starting point, and will give you something executable almost immediately, which you can then modify to your needs.

WizardProject2

Finally, the last page in the wizard allows you select a jBPM runtime, as shown below. You can either use the default runtime (as configured for you workspace, in your workspace preferences), or you can select a specific runtime for this project. For more information about runtimes and how to create them, see the section on jBPM runtimes in this chapter.

You can also select which version of jBPM you want to generate sample code for. By default it will generate an example using the latest jBPM 6.x API, but you could also generate examples using the old jBPM 5.x API. Note that you yourself are responsible for making sure that the code you generate can be understood by the runtime (for example, if you create an example using jBPM6 API but select a jBPM5 runtime, your sample will not compile). Also note that, if you want to execute a jBPM5 example on jBPM6, you will need to have the knowledge-api JAR inside your jBPM6 runtime, as this is responsible for the backwards compatibility of the jBPM5 API in jBPM6.

WizardProject3

When you selected the simple 'hello world' example, the result is shown below. Feel free to experiment with the plug-in at this point.

WizardProjectStructure
Figure 241. New jBPM project artifacts

The newly created project contains an example process file (sample.bpmn) in the src/main/resources directory and an example Java file (ProcessTest.java) that can be used to test the process in a jBPM engine. You’ll find this in the folder src/main/java, in the com.sample package. All the other JARs that are necessary during execution are also added to the classpath in a custom classpath container called jBPM Library.

You can also convert an existing Java project to a jBPM project by selecting the "Convert to jBPM Project" action. Right-click the project you want to convert and under the "Configure" category (at the bottom) select "Convert to jBPM Project". This will add the jBPM Library to your project’s classpath.

18.1.3. New BPMN2 Process Wizard

You can create a new process simply as an empty text file with extension ".bpmn", or use the "New BPMN2 Process" wizard to do so. To create a new process, in the "File" menu select "New" and then "Other …​" and under the jBPM category, select "BPMN2 Process" and click "Next >". In the next dialog, you should select the folder where the process should be created (for example the src/main/resources folder of your project) and a name for the process. Clicking "Finish" should create your new process (by default it should only contain one start node) and open it so you can start editing it.

18.1.4. jBPM Runtime

A jBPM runtime is a collection of JAR files that represent one specific release of the jBPM project JARs. To create a runtime, download the binary distribution of the version of jBPM you want to use and unzip on your local file system. You must then point the IDE to the release of your choice by selecting the folder where these JARs are located. If you want to create a new runtime based on the latest jBPM project JARs included in the plugin itself, you can also easily do that. You are required to specify a default jBPM runtime for your Eclipse workspace, but each individual project can override the default and select the appropriate runtime for that project specifically.

18.1.4.1. Defining a jBPM Runtime

To define one or more jBPM runtimes using the Eclipse preferences view you open up your Preferences, by selecting the "Preferences" menu item in the menu "Window". A "Preferences" dialog should show all your settings. On the left side of this dialog, under the jBPM category, select "Installed jBPM runtimes". The panel on the right should then show the currently defined jBPM runtimes. For example, if you used the jBPM Installer, it should look like the figure below.

PreferencesRuntimes

To define a new jBPM runtime, click on the "Add" button. A dialog such as the one shown below should pop up, asking for the name of your runtime and the location on your file system where it can be found.

PreferencesAddRuntime

In general, you have two options:

  1. If you simply want to use the default JAR files as included in the jBPM Eclipse plugin, you can create a new jBPM runtime automatically by clicking the "Create a new jBPM Runtime …​" button. A file browser will show up, asking you to select the folder on your file system where you want this runtime to be created. The plugin will then automatically copy all required dependencies to the specified folder. Make sure to select a unique name for the newly created runtime and click "OK" to register this runtime.

    Note that creating a jBPM runtime from the default JAR files as included in the jBPM Eclipse plugin is only recommended to get you started the first time and for very simple use cases. The runtime that is created this way only contains the minimal set of JARs, and therefore doesn’t support a significant set of features, including for example persistence. Make sure to create a full runtime (using the second approach) for real development.

  2. If you want to use one specific release of the jBPM project, you should create a folder on your file system that contains all the necessary jBPM libraries and dependencies (for example by downloading the binary distribution and unzipping it on your local file system). Instead of creating a new jBPM runtime as explained above, give your runtime a unique name and click the "Browse …​" button to select the location of this folder containing all the required JARs. Click "OK" to register this runtime.

After clicking the OK button, the runtime should show up in your table of installed jBPM runtimes, as shown below. Click on the checkbox in front of one of the installed runtimes to make it the default jBPM runtime. The default jBPM runtime will be used as the runtime of all your new jBPM projects (in case you didn’t select a project-specific runtime).

You can add as many jBPM runtimes as you need. Note that you will need to restart Eclipse if you changed the default runtime and you want to make sure that all the projects that are using the default runtime update their classpath accordingly.

18.1.4.2. Selecting a runtime for your jBPM project

Whenever you create a jBPM project (using the New jBPM Project wizard or by converting an existing Java project to a jBPM project), the plugin will automatically add all the required JARs to the classpath of your project.

When creating a new jBPM project, the plugin will automatically use the default Drools runtime for that project, unless you specify a project-specific one. You can do this in the final step of the New jBPM Project wizard, as shown below, by deselecting the "Use default Drools runtime" checkbox and selecting the appropriate runtime in the drop-down box. If you click the "Configure workspace settings …​" link, the workspace preferences showing the currently installed jBPM runtimes will be opened, so you can add new runtimes there.

WizardProject3

You can change the runtime of a jBPM project at any time by opening the project properties and selecting the jBPM category, as shown below. Mark the "Enable project specific settings" checkbox and select the appropriate runtime from the drop-down box. If you click the "Configure workspace settings …​" link, the workspace preferences showing the currently installed jBPM runtimes will be opened, so you can add new runtimes there. If you deselect the "Enable project specific settings" checkbox, it will use the default runtime as defined in your global workspace preferences.

PreferencesProject

18.1.5. jBPM Maven Project Wizard

The aim of the new Maven project wizard is to set up an executable sample project to start using processes immediately (but not as normal Java project with all jBPM dependencies added using a jBPM library but by using Maven (and thus a pom.xml) to define your project’s properties and dependencies. This wizard will set up a Maven project using a pom.xml, and include a sample process and Java class to execute it. To create a new jBPM Maven project, in the "File" menu select "New" and then "Project …​" and under the jBPM category, select "jBPM Project (Maven)". Give your project a name and click finish. The result should be as shown below.

WizardMavenProject

The pom.xml that is generated for your project contains the following:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

  <modelVersion>4.0.0</modelVersion>

  <groupId>com.sample</groupId>
  <artifactId>jbpm-example</artifactId>
  <version>1.0.0-SNAPSHOT</version>

  <name>jBPM :: Sample Maven Project</name>
  <description>A sample jBPM Maven project</description>

  <properties>
    <version.org.jbpm>6.0.0.Final</version.org.jbpm>
  </properties>

  <repositories>
    <repository>
      <id>jboss-public-repository-group</id>
      <name>JBoss Public Repository Group</name>
      <url>http://repository.jboss.org/nexus/content/groups/public/</url>
      <releases>
        <enabled>true</enabled>
        <updatePolicy>never</updatePolicy>
      </releases>
      <snapshots>
        <enabled>true</enabled>
        <updatePolicy>daily</updatePolicy>
      </snapshots>
    </repository>
  </repositories>

  <dependencies>
    <dependency>
      <groupId>org.jbpm</groupId>
      <artifactId>jbpm-test</artifactId>
      <version>${version.org.jbpm}</version>
    </dependency>
  </dependencies>
</project>

In the properties section, you can specify which version of jBPM you would like to use (by default it uses 6.0.0.Final). It adds the JBoss Nexus Maven repository (where all the jBPM JARs and their dependencies are located) to your project and configures the dependencies.

By default, only the jbpm-test JAR is specified as a dependency, as this has transitive dependencies to almost all of the core dependencies you will need. You are free to update the dependencies section however to include only the dependencies you need.

The project also contains a sample process, under src/main/resources, in the com.sample package, and a kmodule.xml configuration file under the META-INF folder. The kmodule.xml defines which resources (processes, rules, etc.) are to be loaded as part of your project. In this case, it is defining a kbase called "kbase" that will load all the resources in the com.sample folder:

<kmodule xmlns="http://www.drools.org/xsd/kmodule">
  <kbase name="kbase" packages="com.sample"/>
</kmodule>

Finally, it also contains a Java class that can be used to execute the sample process. It will first create a kbase called "kbase" (by inspecting the kmodule.xml file and thus loading the sample.bpmn process) and then use a RuntimeManager to get access to a KieSession and TaskService. In this case, it is used to start a process and then complete the tasks created by this process one by one.

18.1.6. Drools Eclipse plugin

The Drools Eclipse Plugin, which is bundled as part of the same Eclipse Update Site as the jBPM Eclipse Plugin, provides similar features for creating and editing business rules, and execute them using the Drools engine. This for example allows you to create and edit .drl files containing business rules. You can combine your processes and rules inside one project and execute them together on the same KieSession.

18.2. Debugging

This section describes how to debug processes using the jBPM Eclipse plugin. This means that the current state of your running processes can be inspected and visualized during the execution. Note that we currently don’t allow you to put breakpoints on the nodes within a process directly. You can however put breakpoints inside any Java code you might have (i.e. your application code that is invoking the engine or invoked by the engine, listeners, etc.) or inside rules (that could be evaluated in the context of a process). At these breakpoints, you can then inspect the internal state of all your process instances.

When debugging the application, you can use the following debug views to track the execution of the process:

  1. The process instances view, showing all running process instances (and their state). When double-clicking a process instance, the process instance view visually shows the current state of that process instance at that point in time.

  2. The audit view, showing the audit log (note that you should probably use a threaded file logger if you want to session to save the audit event to the file system on regular intervals, so the audit view can be update to show the latest state).

  3. The global data view, showing the globals.

  4. Other views related to rule execution like the working memory view (showing the contents (data) in the working memory related to rule execution), the agenda view (showing all activated rules), etc.

18.2.1. The Process Instances View

The process instances view shows the process instances currently running in the selected ksession. To be able to use the process instances view, first open the Process Instances view (Window - Show View - Other …​ and under the Drools category select Process Instances and Process Instance). Tip: it might be useful to drag the Process Instance view to the Outline View and slightly enlarge it, as shown in the screenshot below, so you can see both the Process Instances and Process Instance views at the same time.

Next, use a (regular) Java breakpoint to stop your application at a specific point (for example right after starting a new process instance). In the Debug perspective, select the ksession you would like to inspect, and the Process Instances view should show the process instances that are currently active inside that ksession. For example, the screenshot below shows one running process instance (with id "1"). When double-clicking a process instance, the process instance viewer will graphically show the progress of that process instance. An example where the process instance is waiting for a human actor to perform "Task 1" is shown below.

The process instances view shows the process instances currently active inside the selected ksession. Note that, when using persistence, process instances are not kept in memory inside the ksession, as they are stored in the database as soon as the command completes. Therefore, you will not be able to use the Process Instances view when using persistence. For example, when executing a JUnit test using the JbpmJUnitBaseTestCase, make sure to call "super(true, false);" in the constructor to create a runtime manager that is not using persistence.

Debugging

When you double-click a process instance in the process instances view and the process instance view complains that it cannot find the process, this means that the plugin wasn’t able to find the process definition of the selected process instance in the cache of parsed process definitions. To solve this, simply change the process definition in question and save again (so it will be parsed) or rebuild the project that contains the process definition in question.

18.2.2. The Audit View

The audit view can be used to show the all the events inside an audit log in a tree-based manner. An audit log is an XML-based log file which contains a log of all the events that occurred while executing a specific ksession. To create a logger, use KieServices to create a new logger and attach it to a ksession. Be sure to close the logger after usage.

KieRuntimeLogger logger = KieServices.Factory.get().getLoggers()
    .newThreadedFileLogger(ksession, "mylogfile", 1000);
// do something with the ksession here
logger.close();

To be able to use the Audit View, first open it (Window - Show View - Other …​ and under the Drools category select Audit). To open up a log file in the audit view, open the selected log file in the audit view (using the "Open Log" action in the top right corner), or simply drag and drop the log file from the Package Explorer or Navigator into the audit view. A tree-based view is generated based on the data inside the audit log. An event is shown as a subnode of another event if the child event is caused by (a direct consequence of) the parent event. An example is shown below.

audit

Note that the file-based logger will only save the events on close (or when a certain threshold is reached). If you want to make sure the events are saved on a regular interval (for example during debugging), make sure to use a threaded file logger, so the audit view can be update to show the latest state. When creating a threaded file logger, you can specify the interval after which events should be saved to the file (in milliseconds).

18.3. Synchronizing with Workbench Repositories

From Eclipse, you can synchronize your local workspace with one or more repositories that are managed inside the workbench application. This enables collaboration between developers using Eclipse and users of the web-based workbench (business analysts or end users for example). Synchronization between the workbench repositories and your local version of these projects is done using Git (a popular distributed source code version control system).

When creating and executing processes inside Eclipse, you are creating them on your local file system. You can however also import an existing repository from the Workbench, apply changes and push these changes back into the Workbench repositories. We are using existing Git tools for this. Note that this section will describe how to do this using the EGit tooling (Eclipse Tooling for Git which comes by default with most versions of Eclipse), but feel free to use your preferred Git tool instead.

This section is not intended to explain what Git is, or how to use EGit, in detail. If you don’t have any experience with Git and/or EGit, it might be recommended to read up on them first if necessary.

18.3.1. Importing a workbench repository

To import an existing repository from the workbench, you can use the EGit import wizard. In the File menu, select "Import …​" and in the Git category, select "Projects from Git" and click "Next >". This should open a new dialog where you should select the location of the repository you would like to import. Since we are connecting to a repository that is managed by the workbench application, select "URI" and click "Next >" once more.

Use the following URI to connect to your workbench repositories:

ssh://<hostname>:8001/<repository_name>

For example, if you are running the workbench application on your local host (for example by using the jbpm-installer), and you want to import the jbpm-playground repo, use the following URI:

ssh://localhost:8001/jbpm-playground

Note that you can change the port that is used by the server to provide ssh access to the git repository if necessary, using the system property org.uberfire.nio.git.ssh.port

Fill in the URI of the repository you would like to import, as for example shown below, and click "Next >".

ImportWizard1

You will be asked to select which branch you would like to import. Select the master branch and click "Next >" again.

Finally, you need to specify where on your local file system you would like this repository to be created. Fill in the directory (you can use the Browse button to select the folder in question, and if necessary you can create a new folder there as well) and click "Next >". This will now download the repository to the folder you just selected.

ImportWizard2

You still need to import the repository you just downloaded as a project in your Eclipse workspace. Select "Import as general project" and after clicking "Next >", give it a name and click "Finish". After doing so, your workspace should now contain your repository, and you should be able to browse, open and edit the various assets inside.

ImportWizard3

18.3.2. Committing changes to the workbench

You can commit and push changes (you do locally) back to the workbench repositories. To commit changes, right-click on your repository project and select "Team → Commit …​". A new dialog pops up, showing all the changes you have on your local file system. Select the files you want to commit (if you double-click them, you can get an overview of the changes you did for that file), provide an appropriate commit message and click "Commit".

Commit

Once you’ve committed your change to your local git, you still need to push it to the workbench repository. Right-click your project again, and select "Team → Push to Upstream".

You are only allowed to push changes upstream if your local version includes all recent changes (otherwise you might be overriding someone else’s changes). You might be forced to update (and if necessary resolve conflicts) before you are allowed to commit any changes.

18.3.3. Updating from to the workbench

To retrieve the latest changes from the workbench repository, right-click your repository project and select "Team → Fetch from Upstream". This will fetch all changes from the workbench repository, but not yet apply them to your local version. Now right-click your project again and select "Team → Merge …​". In the dialog that pops up next, you need to select "origin/master" branch (under Remote Tracking) to indicate that you want to merge in all changes from the original repository in the workbench, and click "Merge".

Update

It is possible that you have committed and/or conflicting changes in your local version, you might have to resolve these conflicts and commit the merge results before you will be able to complete the merge successfully. It is recommended to update regularly, before you start updating a file locally, to avoid merge conflicts being detected when trying to commit changes.

18.3.4. Working on individual projects

When you import a repository, it will download all the projects that are inside that repository. It is however useful to mount one specific project as a separate Java project in Eclipse. When you do this, Eclipse will be able to interpret the information in the project pom.xml file (that you created in the workbench), download and include any dependencies you specified, compile any Java classes you have in your project (that you for example created with the data modeler), etc.

To do so, right-click on one of the projects in your repository project and select "Import …​" and under the Maven category, select "Existing Maven Projects" (as shown below) and click Next.

ImportProject1

In the next page, you should see the pom.xml of the project you selected. Click Finish.

ImportProject2

If your project requires some of the jBPM libraries to correctly compile and/or execute any Java classes in your project (for example if you have test classes in your project that start up a jBPM engine and execute some tests for your project, or if you are using the data modeler, which will add some annotations to the generated Java classes), you still need to add the jBPM libraries to the classpath of your project. To do so, simply convert your project into a jBPM project, which will add the jBPM library to your project’s classpath. Right-click your project and select "Configure → Convert to jBPM Project". Your project should now have a jBPM Library added to its classpath (it might be necessary to clean your project to pick up this change and recompile all Java classes).

ImportProject3

19. Eclipse BPMN 2.0 Modeler

19.1. Overview

The Eclipse BPMN 2.0 Modeler allows you to specify business processes, choreographies, etc. using the BPMN 2.0 XML syntax (including BPMNDI for the graphical information). The editor itself is based on the Eclipse Graphiti framework and the Eclipse BPMN 2.0 EMF meta-model.

Features:

  • It supports almost all BPMN 2.0 process constructs and attributes (including lanes and pools, annotations and all the BPMN2 node types).

  • Added additional support for the few custom attributes that jBPM introduces using a special jBPM Target Runtime.

  • Allows you to configure which elements and attributes you want use when modeling processes (so we can limit the constructs for example to the subset currently supported by jBPM, which is a profile supported by default, or even more if you like).

The BPMN2 Modeler project is being developed at eclipse.org, sponsored by Red Hat/JBoss. Red Hat understands the benefits of developing software in the community, and therefore, the Eclipse BPMN 2.0 Modeler was developed not just for the jBPM project only, but it can be used in a much broader context and is fully spec compliant. jBPM-specific features are developed as part of a separate jBPM Target Runtime. We welcome other organizations in contributing to this modeler as well and (re)using the generic functionality and/or defining their own target runtime if necessary. Not only is this a good thing for the community, but it also leaves the path open for the jBPM suite to evolve as new features are requested by customers.

Many thanks go out to the people at Codehoop that did a great job in creating a first version of this editor.

19.2. Installation

The jBPM installer is capable of downloading and installing an Eclipse installation, including the Eclipse BPMN2 Modeler and the Drools and jBPM Eclipse plugin (with a full jBPM runtime preconfigured).

Using the jBPM installer is definitely the recommended starting point for most users.

You can however also download and install the jBPM Eclipse Plugin manually. To do so, you need Eclipse 3.6.2 (Helios) or newer. To install, startup Eclipse and install the Eclipse BPMN 2.0 Modeler from the following update site (from menu Help → Install new software and then add the update site in question by clicking the Add button, filling in a name and the correct URL as shown below). It will automatically download all other dependencies as well (e.g. Graphiti etc.)

Eclipse 3.7 - 4.2.1 (Indigo - Juno): http://download.eclipse.org/bpmn2-modeler/updates/juno

The project is hosted at eclipse.org and open for anyone to contribute. The project home page can he found here:

Sources are available here (using Eclipse Public License v1.0):

A community forum for posting questions and exchanging ideas is also available here:

A Bugzilla bug tracking system is available for reporting new bugs, or checking the status of existing bugs, here:

19.3. Documentation

The Eclipse BPMN 2.0 Modeler documentation is available at:

It contains various screencasts but also a full user guide, describing all its features in detail:

Here are some screenshots of the editor in action.

EclipseJBPM
properties
bpmn2 1 thumb

Integration

Integrating jBPM with other technologies, frameworks, etc.

20. Integration

20.1. Maven

Apache Maven is used by jBPM for two main purposes:

  • as deployment units that gets installed into runtime environment for execution

  • as dependency management tool for building systems based on jBPM - embedding jBPM into application

20.1.1. Maven artifacts as deployment units

Since version 6, jBPM provides simplified and complete deployment mechanism that is based entirely on Apache Maven artifacts. These artifacts also known as kjars are simple JAR files that include a descriptor for KIE system to produce KieBase and KieSession. Descriptor of the kjar is represented as XML file named kmodule.xml and it can be:

  • empty to apply all defaults

  • custom configuration of KieBase and KieSession

<kmodule xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.drools.org/xsd/kmodule">
</kmodule>

Empty kmodule.xml that provides all defaults for the kjar:

  • single default KieBase that

    • contains all assets from all packages

    • event processing mode set to - cloud

    • equality behaviour set to - identity

    • declarative agenda is disabled

    • scope set to - ApplicationScope - valid for CDI integrations only

  • single default stateless KieSession that

    • is bound to above (single, default) KieBase

    • clock type is set to - real time

    • scope set to - ApplicationScope - valid for CDI integrations only

  • single default stateful KieSession that

    • is bound to above (single, default) KieBase

    • clock type is set to - real time

    • scope set to - ApplicationScope - valid for CDI integrations only

All these and more can be configured manually via kmodule.xml when defaults are not enough. The complete set of elements can be found in xsd schema of kmodule.xml.

<kmodule xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="https://www.drools.org/xsd/kmodule">
  <kbase name="defaultKieBase" default="true" eventProcessingMode="cloud" equalsBehavior="identity" declarativeAgenda="disabled" scope="javax.enterprise.context.ApplicationScoped" packages="*">
    <ksession name="defaultKieSession" type="stateful" default="true" clockType="realtime" scope="javax.enterprise.context.ApplicationScoped">
        <workItemHandlers>
            <workItemHandler name="CustomTask" type="FQCN_OF_HANDLER" />
        </workItemHandlers>
        <listeners>
            <listener type="FQCN_OF_EVENT_LISTENER" />
        </listeners>
    </ksession>
    <ksession name="defaultStatelessKieSession" type="stateless" default="true" clockType="realtime" scope="javax.enterprise.context.ApplicationScoped"/>
  </kbase>
</kmodule>

As illustrated in the listing above the kmodule.xml provides flexible way of instructing the runtime engine on what should be configured and how. The example above does not present all available options, but these are the most common when working with processes.

Important to note is that when using RuntimeManager, KieSession instances are created by the RuntimeManager instead of by KieContainer but kmodule.xml (or model in general) is aways used as a base of the construction process. KieBase although is always taken from KieContainer.

Kjars are represented same way as any other Maven artifact - by Group Artifact Version which is then represented as ReleaseId in KIE API. This the the only thing required to deploy kjar into runtime environment such as KIE Workbeanch.

20.1.2. Use Maven for dependency management

When building systems that embed jBPM as workflow engine the simplest way is to configure all dependencies required by jBPM via Apache Maven. jBPM provides set of BOMs (Bill Of Material) to simplify what artifacts needs to be declared. Common way to start with integration of custom application and jBPM is to define dependency management:

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <version.org.drools>6.0.0.Final</version.org.drools>
    <version.org.jbpm>6.0.0.Final</version.org.jbpm>
    <hibernate.version>4.2.0.Final</hibernate.version>
    <hibernate.core.version>4.2.0.Final</hibernate.core.version>
    <slf4j.version>1.6.4</slf4j.version>
    <jboss.javaee.version>1.0.0.Final</jboss.javaee.version>
    <logback.version>1.0.9</logback.version>
    <h2.version>1.3.161</h2.version>
    <btm.version>2.1.4</btm.version>
    <junit.version>4.8.1</junit.version>
  </properties>
  <dependencyManagement>
    <dependencies>
      <!-- define drools BOM -->
      <dependency>
        <groupId>org.drools</groupId>
        <artifactId>drools-bom</artifactId>
        <type>pom</type>
        <version>${version.org.drools}</version>
        <scope>import</scope>
      </dependency>
      <!-- define drools BOM -->
      <dependency>
        <groupId>org.jbpm</groupId>
        <artifactId>jbpm-bom</artifactId>
        <type>pom</type>
        <version>${version.org.jbpm}</version>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>

Above should be declared in top level pom.xml so all modules that need to use KIE (drools and jBPM) API can access it.

Next, module(s) that would operate on KIE API should declare following dependencies:

    <dependency>
      <groupId>org.jbpm</groupId>
      <artifactId>jbpm-flow</artifactId>
    </dependency>
    <dependency>
      <groupId>org.jbpm</groupId>
      <artifactId>jbpm-flow-builder</artifactId>
    </dependency>
    <dependency>
      <groupId>org.jbpm</groupId>
      <artifactId>jbpm-bpmn2</artifactId>
    </dependency>
    <dependency>
      <groupId>org.jbpm</groupId>
      <artifactId>jbpm-persistence-jpa</artifactId>
    </dependency>
    <dependency>
      <groupId>org.jbpm</groupId>
      <artifactId>jbpm-human-task-core</artifactId>
    </dependency>
    <dependency>
      <groupId>org.jbpm</groupId>
      <artifactId>jbpm-runtime-manager</artifactId>
    </dependency>
    <dependency>
      <groupId>org.slf4j</groupId>
      <artifactId>slf4j-api</artifactId>
      <version>${slf4j.version}</version>
    </dependency>

Above are the main runtime dependencies, regardless of where the application is deployed (application server, servlet container, standalone app). A good practice is to test the workflow components to ensure they work properly before actual deployment and thus following test dependencies should be defined:

    <!-- test dependencies -->
    <dependency>
      <groupId>org.jbpm</groupId>
      <artifactId>jbpm-shared-services</artifactId>
      <classifier>btm</classifier>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>ch.qos.logback</groupId>
      <artifactId>logback-classic</artifactId>
      <version>${logback.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>${junit.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-entitymanager</artifactId>
      <version>${hibernate.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.hibernate</groupId>
      <artifactId>hibernate-core</artifactId>
      <version>${hibernate.core.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>com.h2database</groupId>
      <artifactId>h2</artifactId>
      <version>${h2.version}</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.codehaus.btm</groupId>
      <artifactId>btm</artifactId>
      <version>${btm.version}</version>
      <scope>test</scope>
    </dependency>

Last but not least, define the JBoss Maven repository for artifacts resolution:

  <repositories>
    <repository>
      <id>jboss-public-repository-group</id>
      <name>JBoss Public Repository Group</name>
      <url>http://repository.jboss.org/nexus/content/groups/public/</url>
      <releases>
        <updatePolicy>never</updatePolicy>
      </releases>
      <snapshots>
        <updatePolicy>daily</updatePolicy>
      </snapshots>
    </repository>
  </repositories>

That should allow to configure jBPM in your application and provide access to KIE API to operate on processes, rules, events.

20.2. CDI

20.2.1. Overview

jBPM 6 comes with out of the box integration with CDI (Contexts and Dependency Injection). Although most of the API can be used in CDI world there are some dedicated modules that are designed especially for CDI containers. The most important one is jbpm-services-cdi that provides cdi wrappers on top of jbpm services, these shall be used in most of the cases were CDI is available for jBPM integration. It provides following set of services:

  • DeploymentService

  • ProcessService

  • UserTaskService

  • RuntimeDataService

  • DefinitionService

These services are first class citizens for CDI world so they are available for injection in any other CDI bean.

20.2.1.1. DeploymentService

Service responsible for deploying DeploymentUnits into runtime environment. By deploying given deployment unit becomes ready for execution and has RuntimeManager created for it.DeploymentService can next be used to retrieve:

  • RuntimeManager instance for given deployment id

  • DeployedUnit that represents complete deployment process for given deployment id

  • list of all deployed units known to the deployment service

Deployment service stores the deployed units by default in memory and thus in case of a need to restore all previously deployed units, component that uses deployment service needs to store that information itself. Common places for such a store are database, file system, repository of some sort, etc. Deployment service will fire CDI events on deployment and undeployment to allow application components to react real time to these events to be able to store deployments or remove them from the store when they are undeployed.

  • DeploymentEvent with qualifier @Deploy will be fired on deployment

  • DeploymentEvent with qualifier @Undeploy will be fired on undeployment

use CDI observer mechanism to get notification on above events. First to save deployments in the store of your choice:

    public void saveDeployment(@Observes @Deploy DeploymentEvent event) {
        // store deployed unit info for further needs
        DeployedUnit deployedUnit = event.getDeployedUnit();
    }

next to remove it when it was undeployed

    public void removeDeployment(@Observes @Undeploy DeploymentEvent event) {
        // remove deployment with id event.getDeploymentId()
    }

Deployment service comes with deployment synchronization mechanism that allows to persist deployed units into data base (since version 6.2) that is by default enabled. See jbpm services section for more details.

Due to the fact that there might be several implementation of DeploymentService use of qualifiers is needed to instruct CDI container which one shall be injected. jBPM comes with two out of the box:

  • @Kjar - KmoduleDeploymentService that is tailored to work with KmoduleDeploymentUnits that are small descriptor on top of a kjar - recommended to use in most of the cases

  • @Vfs - VFSDeploymentDService that allows to deploy assets directly from VFS (Virtual File System) that is provided by UberFire framework. Due to that fact VFSDeploymentService and VFSDeploymentUnit are not bundled with jbpm core modules but with jbpm-console-ng modules.

The general practice is that every implementation of DeploymentService should come with dedicated implementation of DeploymentUnit as these two provided out of the box.

20.2.1.2. FormProviderService

FormProviderService provides access to form representations usually displayed on UI for both process forms and user task forms. It is built on concept of isolated FormProviders that can provide different capabilities and be backed by different technologies. FormProvider interface describes contract for the implementations

public interface FormProvider {

    int getPriority();

    String render(String name, ProcessDesc process, Map<String, Object> renderContext);

    String render(String name, Task task, ProcessDesc process, Map<String, Object> renderContext);
}

Implementations of FormProvider interface should always define priority as this is the main driver for the FormProviderService to ask for the content of the form of a given provider. FormProviderService will collect all available providers and iterate over them asking for the form content (rendered) in their priority order. The lower the number the higher priority it gets during evaluation, e.g. provider with priority 5 will be evaluated before provider with priority 10. FormProviderService will iterate over available providers as long as one delivers the content. In the worse case scenario, simple text based forms will be returned.

jBPM comes with following FormProviders out of the box:

  • Fremarker based implementation to support jbpm version 5 process and task forms - priority 3

  • Default forms provider, considered last resort if none of the other providers deliver content this one will always provide simplest possible forms - lowest priority (1000)

  • when form modeler is used there is additional FormProvider available to deliver forms modeled in that tool - priority 2

20.2.1.3. RuntimeDataService

RuntimeDataService provides access to actual data that is availabe on runtime such as

  • available processes to be executed - with various filters

  • active process instances - with various filters

  • process instance history

  • process instance variables

  • active and completed nodes of process instance

Default implementation of RuntimeDataService is observing deployment events and index all deployed processes to expose them to the calling components. So whatever gets deployed RuntimeDataService will be aware of that.

20.2.1.4. DefinitionService

Service that provides access to process details stored as part of BPMN2 XML.

Before using