When extending an existing Portal Container, the name of the portal in the Extension's configuration happens to be the same as the name of the existing Portal Container. The configuration (and other aspects) of the existing Portal Container can thus be shadowed by the Extension. Using this approach, many aspects of an available Portal Container can be customized, such as:
- Groovy Templates of Portlets
- Portlet Skins, CSS and Images
- Navigation Definitions and Pages
A schematic representation of the shadowing mechanism can be seem in the following diagram:
The principal role in the extension mechanism is played by the definition of the Portal Container which happens in conf/configuration.xml of the Extension EAR. Consider the following snippet coming from Portal Extension Quickstart. Note how the name parameter of the PortalContainerDefinition is set to "portal". Since a Portal Container called "portal" already exists in the default GateIn Portal installation, we actually redefine that existing Portal Container here:
Other resources available in an existing Portal Container can be customized in a similar way. Please refer to the following sections for more details.