Configuring a BIRT Viewer Java Extension

The BIRT Design Engine API provides the IBirtViewerExtension, IBirtViewerContext, IBirtViewerOp, and IBirtViewer Session Java interfaces to extend the functionality of BIRT Viewer. Classes implementing these interfaces are associated with the BIRT Viewer web application when they are added in the birtviewer-extension.xml configuration file. Its location is:

<context root>\WEB-INF\birtviewer-extension.xml

For example, to enable myIVExtension.jar to operate on BIRT Viewer, add an entry to birtviewer-extension.xml as follows:

<?xml version="1.0" encoding="UTF-8" ?>

<InteractiveViewer>com.actuate.sample.MyIvExtension
</InteractiveViewer>

</BirtWebViewerExtension>

Save the compiled code archive to the <context root>\WEB-INF\lib folder for the BIRT Viewer web application and restart the application to enable the custom interface. The interfaces are part of the com.actuate.birtviewer.extension package of the BIRT Design Engine API.

The IBirtViewerExtension interface defines the event handler methods that activate implemented code, as follows:

package com.actuate.birtviewer.extension;

public interface IBirtViewerExtension{

// Event handler that runs when a design changes

void afterDesignChange( IBirtViewerContext context, IBirtViewerOp operation, ReportDesignHandle designHandle );

// Event handler after design get opened.

void afterDesignOpen( IBirtViewerContext context, ReportDesignHandle designHandle );

// Event handler that runs when a design is saved

void afterDesignSave( IBirtViewerContext context, IBirtViewerOp operation, ReportDesignHandle designHandle, String path );

//Event handler that runs when viewer creates a new session object

void afterViewerSessionStart( IBirtViewerContext context );

// Event handler that runs before a design change occurs

void beforeDesignChange( IBirtViewerContext context, IBirtViewerOp operation, ReportDesignHandle designHandle );

// Event handler that runs before a design opens

void beforeDesignOpen( IBirtViewerContext context, String path );

// Event handler that runs before a design is saved

boolean beforeDesignSave( IBirtViewerContext context, IBirtViewerOp operation, ReportDesignHandle designHandle, String path );

// Event handler before soap response get sent back.

void beforeResponse( IBirtViewerContext context, IBirtViewerOp operation, GetUpdatedObjectsResponse response );

// Triggered when session object gets destroyed.

void beforeViewerSessionClose( IBirtViewerSession session );

}

The IBirtViewerContext interface defines methods that retrieve information from the HTTP session, as follows:

package com.actuate.birtviewer.extension;

public interface IBirtViewerContext {

// Gets the base URL for the viewer

String getAppBaseUrl( );

// Gets reportlet id/bookmark if user is working on a reportlet.

String getReportletId( );

// Gets the extended session object

IBirtViewerSession getSession( );

// Gets the current user name

String getUserName( );

// Gets the volume profile name

String getVolumeProfile( );

// Gets the resource folder name

String getVolumeResourceFolder( );

}

The IBirtViewerOp interface defines methods that retrieve information from the extended session for BIRT Viewer, as follows:

package com.actuate.birtviewer.extension;

public interface IBirtViewerOp {

// Gets column ids if target element is a table

String[] getColumnIIds( );

// Gets the operation name

String getName( );

// Gets the target element instance ids

String[] getTargetIIds( );

// Get target element type

String getTargetType( );

}

The IBirtViewerSession interface defines methods that retrieve and set a session from the extended session for BIRT Viewer, as follows:

package com.actuate.birtviewer.extension;

public interface IBirtViewerSession {

// Check whether key exists.

boolean containsKey( String key );

//Get attribute from session.

Object getAttribute( String key );

//Set attribute into session.

void setAttribute( String key, Object attribute );

}