Bug 177504 Engine doesn't provide SubQuery for extended item
Engine doesn't provide SubQuery for extended item, so chart can't use container's binding to execute the query. If possible, engine could provide an option for extended item to choose whether engine could create the query, so extended item won't create SubQuery by itself.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/presentation/LocalizedContentVisitor.java
}
			try
			{
				Object output = itemPresentation.onRowSets( rowSets );
				if ( output != null )
				{
					int type = itemPresentation.getOutputType( );
					String imageMIMEType = itemPresentation.getImageMIMEType( );
					generatedContent = processExtendedContent( content, type, output, imageMIMEType );
				}
				itemPresentation.finish( );
			}
			catch ( BirtException ex )
			{
				context.addException( design.getHandle( ), ex );
				logger.log( Level.SEVERE, ex.getMessage( ), ex );
			}
		}
		return generatedContent;
	}
	/**
	 * handle the content created by the IPresentation
	 * 
	 * @param item
	 *            extended item design
	 * @param emitter
	 *            emitter used to output the contnet
	 * @param content
	 *            ext content
	 * @param type