Bug 136820 viewer supports render report in pdf format
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/service/ReportEngineService.java
missingParameter = true;
					break;
				}
			}
		}
		return missingParameter;
	}
	/**
	 * uses to clear the data cach.
	 * 
	 * @param dataSet
	 *            the dataset handle
	 * @throws BirtException
	 */
	public void clearCache( DataSetHandle dataSet ) throws BirtException
	{
		DataSessionContext context = new DataSessionContext(
				DataSessionContext.MODE_DIRECT_PRESENTATION, dataSet
						.getModuleHandle( ), null );
		DataRequestSession requestSession = DataRequestSession
				.newSession( context );
		IModelAdaptor modelAdaptor = requestSession.getModelAdaptor( );
		DataSourceHandle dataSource = dataSet.getDataSource( );
		IBaseDataSourceDesign sourceDesign = modelAdaptor
				.adaptDataSource( dataSource );
		IBaseDataSetDesign dataSetDesign = modelAdaptor.adaptDataSet( dataSet );
		requestSession.clearCache( sourceDesign, dataSetDesign );
	}
}