Bug 185898 ReportItemHandle needs to add two method: getAvailableDataBindingReferenceList and getDataBindingType.
ReportItemHandle needs to add two method: getAvailableDataBindingReferenceList and getDataBindingType. The first method provider the available ReportItem list of DataBindingReference. The second method provider the type of the DataBinding.
model/org.eclipse.birt.report.model.tests/test/org/eclipse/birt/report/model/api/ReportItemHandleTest.java
}
		catch ( SemanticException e )
		{
			assertEquals( PropertyValueException.DESIGN_EXCEPTION_VALUE_EXISTS,
					e.getErrorCode( ) );
		}
		
		newCol.setName( "Number" );
		propertyHandle.replaceItem( col, newCol );
		
		tableHandle.clearProperty( IReportItemModel.BOUND_DATA_COLUMNS_PROP );
		assertNull( tableHandle
				.getListProperty( IReportItemModel.BOUND_DATA_COLUMNS_PROP ) );
		
		GroupHandle groupHandle = designHandle.getElementFactory( )
				.newTableGroup( );
		groupHandle.setName( "NewGroup" );
		tableHandle.getGroups( ).add( groupHandle );
		ComputedColumn groupCol = StructureFactory.createComputedColumn( );
		groupCol.setName( "data item1" );
		groupCol
				.setExpression( "Total.sum(row[\"CUSTOMERNUMBER\"] , null , null )" ); 
		groupCol.setAggregateOn( "NewGroup" );
		groupCol.setDataType( DesignChoiceConstants.PARAM_TYPE_STRING );
		
		tableHandle.addColumnBinding( groupCol, false );
		ComputedColumn tableCol = StructureFactory.createComputedColumn( );
		tableCol.setName( "data item2" );
		tableCol
				.setExpression( "Total.sum(row[\"CUSTOMERNUMBER\"] , null , null )" );