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
ComputedColumnHandle column = (ComputedColumnHandle) columns.next( );
		verifyColumnValues( column );
		DataItemHandle data2 = (DataItemHandle) designHandle
				.findElement( "myData2" ); 
		columns = data2.columnBindingsIterator( );
		column = (ComputedColumnHandle) columns.next( );
		verifyColumnValues( column );
		assertEquals( "myData1", data2.getDataBindingReferenceName( ) ); 
		DataItemHandle newData = (DataItemHandle) designHandle
				.findElement( "myData3" ); 
		newData.setDataBindingReference( data2 );
		columns = newData.columnBindingsIterator( );
		column = (ComputedColumnHandle) columns.next( );
		verifyColumnValues( column );
		try
		{
			newData.setDataBindingReference( newData );
			fail( );
		}
		catch ( SemanticException e )
		{
			assertEquals(
					SemanticError.DESIGN_EXCEPTION_CIRCULAR_ELEMENT_REFERNECE,
					e.getErrorCode( ) );
		}
		try
		{
			data1.setDataBindingReference( data2 );
			fail( );
		}