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
{
			String text = localize( label, label.getLabelKey( ), label.getLabelText( ) );
			label.setText( text );
		}
	}
	public Object visitText( ITextContent text, Object value )
	{
		handleOnRender( text );
		return value;
	}
	/**
	 * handle the foreign content object.
	 * 
	 * Foreign content can be created by following design element:
	 * <li> Text(HTML). It will create a TEMPLATE_TYPE foreign object.
	 * <li> MultiLine(HTML). It will create a HTML_TYPE forign object
	 * <li> MultiLine(PlainText).It will create a TEXT_TYPE foreign object
	 * <li> Extended item. It will create a
	 * TEXT_TYPE/HTML_TYPE/IMAGE_TYPE/VALUE_TYPE foreign object.
	 * 
	 */
	public Object visitForeign( IForeignContent foreignContent, Object value )
	{
		IReportContent reportContent = getReportContent( );
		
		String rawFormat = foreignContent.getRawType( );
		Object rawValue = foreignContent.getRawValue( );
		if ( IForeignContent.TEMPLATE_TYPE.equals( rawFormat ) )
		{
			handleOnRender( foreignContent );