Bug 161501 [Smoke] Chart can not be previewed in Web Viewer & HTML
Chart can not be previewed in Web Viewer & HTML Steps to reproduce: 1. Create a chart. 2. Preveiw in Web Viewer/ HTML. Expected result: Chart can be previewed. Actual result: No chart is shown.
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/service/ReportEngineService.java
*/
	public void clearCache( DataSetHandle dataSet ) throws BirtException
	{
		DataSessionContext context = new DataSessionContext(
				DataSessionContext.MODE_DIRECT_PRESENTATION, dataSet
						.getModuleHandle( ), null );
		DataRequestSession requestSession = DataRequestSession
				.newSession( context );
		IModelAdapter modelAdaptor = requestSession.getModelAdaptor( );
		DataSourceHandle dataSource = dataSet.getDataSource( );
		IBaseDataSourceDesign sourceDesign = modelAdaptor
				.adaptDataSource( dataSource );
		IBaseDataSetDesign dataSetDesign = modelAdaptor.adaptDataSet( dataSet );
		requestSession.clearCache( sourceDesign, dataSetDesign );
	}
	/**
	 * @param maxRows
	 */
	public void setMaxRows( int maxRows )
	{
		if ( config != null )
		{
			config.setMaxRowsPerQuery( maxRows );
		}
	}
	/**
	 * Collects all the distinct values for the given element and
	 * bindColumnName. This method will traverse the design tree for the given
	 * element and get the nearest binding column holder of it. The nearest
	 * binding column holder must be a list or table item, and it defines a