Bug 213126 Add support for DataEngine-leve dataset cache
In many cases the DataEngine-leve dataset cache is useful which ensure that a dataset is executed one time during rendering one report. To support this feature a new dataset property should be added. The Birt customer can choose whether this dataset need to be cached or not by setting the property in deisgn time.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/parser/JointDataSetParseTest.java
assertEquals(
				"value2 expression", ( (FilterCondition) filters.get( 0 ) ).getValue2( ) ); 
	}
	/**
	 * Tests joint data set can be correctly written into design file
	 * 
	 * @throws Exception
	 *             design file exception
	 */
	public void testWriter( ) throws Exception
	{
		openDesign( inputFileName );
		JointDataSetHandle dataSet = designHandle
				.findJointDataSet( "JointDataSet" ); 
		assertNotNull( dataSet );
		dataSet.setRowFetchLimit( 10 );
		DataSetHandle ds1 = designHandle.findDataSet( "DataSet1" );
		ds1.setRowFetchLimit( 50 );
		DataSetHandle ds2 = designHandle.findDataSet( "DataSet2" );
		ds2.setRowFetchLimit( 20 );
		dataSet.addDataSet( "DataSet3" ); 
		JoinCondition condition = StructureFactory.createJoinCondition( );
		condition.setJoinType( DesignChoiceConstants.JOIN_TYPE_LEFT_OUT );
		condition.setOperator( DesignChoiceConstants.JOIN_OPERATOR_EQALS );
		condition.setLeftDataSet( "DataSet2" ); 
		condition.setRightDataSet( "DataSet3" ); 
		condition.setLeftExpression( "leftExpression" ); 
		condition.setRightExpression( "rightExpression" ); 
		PropertyHandle conditionHandle = dataSet
				.getPropertyHandle( JointDataSet.JOIN_CONDITONS_PROP );