Bug 198031 Legend interactivity does not work correctly for drill-throughs
Under Value (Y) Series enable interactivity for the event "Mouse Click" Set action to Hyperlink The type of the hyperlink is Drill-through and the target is the a sub-report Pass parameter to sub-report as row["value_of_the_legend_item"] Suppose there are 3 values, x,y and z No matter which legend item you click (x, y or z), z gets passed as param to the subreport
chart/org.eclipse.birt.chart.reportitem.ui/src/org/eclipse/birt/chart/reportitem/ui/ChartReportItemBuilderImpl.java
final ExpressionBuilder eb = new ExpressionBuilder( sExpression );
		eb.setExpressionProvier( new ExpressionProvider( (ExtendedItemHandle) oContext ) );
		if ( sTitle != null )
		{
			eb.setDialogTitle( eb.getDialogTitle( ) + " - " + sTitle ); 
		}
		if ( eb.open( ) == Window.OK )
		{
			sExpression = eb.getResult( );
		}
		return sExpression;
	}
	/**
	 * @deprecated
	 */
	public String invoke( String sExpression, Object oContext, String sTitle,
			boolean isChartProvider )
	{
		final ExpressionBuilder eb = new ExpressionBuilder( sExpression );
		eb.setExpressionProvier( new ChartExpressionProvider( ) );
		if ( sTitle != null )
		{
			eb.setDialogTitle( eb.getDialogTitle( ) + " - " + sTitle ); 
		}
		if ( eb.open( ) == Window.OK )
		{
			sExpression = eb.getResult( );
		}
		return sExpression;
	}