Bug 167511 [Block]NPE when using customized IStyleProcessor with Chart Generator and no Chart will be rendered
Use a customized IStyleProcessor with Generator.build() and the chart will not be rendered in UI.
chart/org.eclipse.birt.chart.engine/src/org/eclipse/birt/chart/factory/Generator.java
}
			if ( !bAnyQueries )
			{
				throw new ChartException( ChartEnginePlugin.ID,
						ChartException.DATA_BINDING,
						"dataprocessor.exception.AtLeastOneDefnExpMustAssociateY", 
						new Object[]{
								String.valueOf( iCount ), seOrthogonal
						},
						Messages.getResourceBundle( ) );
			}
			
			String[] triggerExprs = DataProcessor.getSeriesTriggerExpressions( seOrthogonal,
					iae );
			if ( triggerExprs != null )
			{
				for ( int t = 0; t < triggerExprs.length; t++ )
				{
					String tgexp = triggerExprs[t];
					if ( !alExpressions.contains( tgexp ) )
					{
						alExpressions.add( tgexp ); 
					}
				}
			}
		}
		return alExpressions;
	}
	private static List getRowExpressions( ChartWithAxes cwa,
			IActionEvaluator iae ) throws ChartException