Scribble User Guide

The pre-requisites for the Scribble design time tools are:

The design time tools are Java based, so you will need a suitable JVM (Java Virtual Machine) to run the tools. If you also intend to generate Java APIs, for use at runtime, then you will need a JDK (Java Development Kit). Download the version 1.6 (or higher) from the http://www.java.com . Once downloaded, follow the instructions to install the JVM or JDK on your system.

The Scribble protocol descriptions can be edited using a standard text editor, and the Scribble tools can be invoked using command line tools (as described in the following chapter). However it is also possible to use the Scribble tools from within the Eclipse IDE environment, by installing the Scribble tools as plugins. If you wish to use this approach, then you will need a version of Eclipse (3.6 or higher) which can be downloaded from the Eclipse website: http://www.eclipse.org .

To install the command line version of the Scribble tools:

The commands can be executed from the bin folder of the Scribble tools distribution. Alternatively, the bin folder can be added to the execution path, to enable the commands to be performed from any folder. For example, on Linux running bash, simply edit the .bash_profile file within your home directory to add:

PATH=$PATH:${path-to-scribble}/bin

NOTE: Currently on Windows it is only possible to run the scripts from the bin folder.

The Eclipse plugins for the Scribble tools can be loaded from an update site using the update manager.

Select the Help->Install New Software... menu item, from your Eclipse environment, and follow the instructions.

If installing a stable or development milestone release of the tools, then the plugins can be installed directly from the network. If installing a nightly build of the plugins, to access the latest (but unstable) version of the tools, then it will be necessary to download the update site as an archive, and point the Eclipse update manager at the downloaded zip file.

The location of the stable, development and nightly builds can be found on the Scribble download page: http://www.jboss.org/scribble/downloads .

Once the Eclipse environment has restarted, and if the distribution has been downloaded and expanded, then the next step is to import the samples into the Eclipse workspace.

This can be done by selecting the Import->General->Existing Projects into Workspace and locating the samples folder from the Scribble distribution.

This will display the set of projects within the samples folder, which can either be individually selected, or all imported at once. Once imported, the Scribble Protocol files can be opened by double clicking the file, to open the protocol context sensitive editor.

The parse command takes a single parameter, which is the path to the file containing the protocol description to be parsed.

For example, if the user is in the top level folder of the Scribble tools distribution, without the bin folder being added to the system path, then the following command can be executed to parse one of the sample protocol descriptions:

bin/parse.sh samples/purchasing/Purchasing.spr

If the supplied file path is not valid, then the command will report an error.

This command will read the protocol description, as shown below, and convert it into an internal object model representation.

import Order;
import CreditCheck;
import CreditOk;
import Confirmation;
import InsufficientCredit;
import OrderRejected;
import OutOfStock;

protocol Purchasing (role Buyer) {
    Buyer introduces Seller;

    Order from Buyer to Seller;

    choice at Seller {
        OutOfStock from Seller to Buyer;
    } or {
        Seller introduces CreditAgency;

        CreditCheck from Seller to CreditAgency;

        choice at CreditAgency {
            CreditOk from CreditAgency to Seller;
            Confirmation from Seller to Buyer;
        } or {
            InsuficientCredit from CreditAgency to Seller;
            OrderRejected from Seller to Buyer;
        }
    }
}

If any errors are detected in the syntax of the parsed protocol description, then these will be reported to the command window.

The validate command takes a single parameter, which is the path to the file containing the protocol description to be validated.

For example, if the user is in the top level folder of the Scribble tools distribution, without the bin folder being added to the system path, then the following command can be executed to validate one of the sample protocol descriptions:

bin/validate.sh samples/purchasing/Purchasing.spr

When this command is performed initially, it will complete without any errors. However if you edit the samples/purchasing/Purchasing.spr file, and change the following line:

Order from Buyer to Seller;

For example, change the Seller role to Seller2 , and then re-run the validate command. This will result in the following error messages:

ERROR: [line 12] Unknown role 'Seller2'

The conforms command takes two parameters, which are both paths to a file containing a protocol description. The first parameter is the protocol description to be checked for conformance against the second parameter's protocol description. So the second parameter is the reference protocol description.

For example, if the user is in the top level folder of the Scribble tools distribution, without the bin folder being added to the system path, then the following command can be executed to check one of the sample protocol descriptions as being conformant with another reference protocol description:

bin/conforms.sh samples/models/conformance_descriptions/OrderProcess.spr samples/models/conformance_descriptions/ReferenceOrderProcess.spr

If you inspect the two process definitions, you will find one difference. The first protocol definition has the following interaction:

MyOrder from Buyer to Seller;

The second, reference protocol description, has the following interaction:

Order from Buyer to Seller;

This results in the following conformance error message:

ERROR: Type mismatch with referenced description, was expecting Order

The project command takes two parameters. The first parameter is the protocol description to be projected and the second parameter is the participant .

For example, if the user is in the top level folder of the Scribble tools distribution, without the bin folder being added to the system path, then the following command can be executed to project one of the sample protocol descriptions:

bin/project.sh samples/purchasing/Purchasing.spr CreditAgency

This results in the following located Protocol being displayed on the console:

import Order;
import CreditCheck;
import CreditOk;
import Confirmation;
import InsufficientCredit;
import OrderRejected;
import OutOfStock;
protocol Purchasing at CreditAgency(role Seller) {
    CreditCheck from Seller;
    choice at CreditAgency {
        CreditOk to Seller;
    } or {
        InsuficientCredit to Seller;
    }
}

The simulate command takes two parameters. The first parameter is the located protocol description and the second parameter is the event list to be simulated against the protocol.

For example, if the user is in the top level folder of the Scribble tools distribution, without the bin folder being added to the system path, then the following command can be executed to simulate the protocol description:

bin/simulate.sh samples/purchasing/Purchasing@Buyer.spr samples/purchasing/Purchasing@Buyer.events

The event file is a comma separated value (csv) format, with the first column representing the event type, and the second representing the value relevant for the event type. The event types are listed below:

The event file used in the sample command above is:

send,Order
receive,Confirmation

and the result of running the command is:

INFO: Validated Send Order
INFO: Validated Receive Confirmation