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
* 
	 * @param data
	 *            data object
	 */
	protected void processData( IDataContent data )
	{
		String helpText = localize( data, data.getHelpKey( ), data.getHelpText( ) );
		data.setHelpText( helpText );
		String text = ""; 
		if ( data.getLabelKey( ) != null || data.getLabelText( ) != null )
		{
			text = localize( data, data.getLabelKey( ), data.getLabelText( ) );
		}
		else
		{
			Object value = data.getValue( );
			if ( value != null )
			{
				IStyle style = data.getComputedStyle( );
				if ( value instanceof Number )
				{
					String format = style.getNumberFormat( );
					NumberFormatter fmt = context.getNumberFormatter( format );
					text = fmt.format( (Number) value );
					CSSValue align = style
							.getProperty( IStyle.STYLE_NUMBER_ALIGN );
					if ( align != null && align != CSSValueConstants.NONE_VALUE )
					{
						data.getStyle( ).setProperty( IStyle.STYLE_TEXT_ALIGN,
								align );