Bug 155365 Can not set data type to "date time" when editing "Data Item"
Description: Can not set data type to "date time" when editing "Data Item" Steps to reproduce: 1. Insert a data item to the layout 2. Name it and set the expression to "a = new Date()" 3. Select the data type to date time 4. Press ok Actual result: An Birt Exception is thrown out. Expected result: No NPE thrown out
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/ui/dialogs/ColumnBindingDialog.java
bindingTable.setInput( inputElement );
		bindingTable.addSelectionChangedListener( new ISelectionChangedListener( ) {
			public void selectionChanged( SelectionChangedEvent event )
			{
				if ( !bindingTable.getSelection( ).isEmpty( ) )
				{
					Object obj = ( (IStructuredSelection) bindingTable.getSelection( ) ).getFirstElement( );
					if ( obj == dummyChoice && !existHighLightColumn( ) )
					{
						bindingTable.refresh( );
						setHihtLightColumn( );
					}
					else if ( obj instanceof ComputedColumnHandle )
					{
						if ( expressionProvider != null )
							expressionCellEditor.setExpressionProvider( expressionProvider );
						else
						{
							ComputedColumnHandle column = (ComputedColumnHandle) obj;
							BindingExpressionProvider provider = new BindingExpressionProvider( column.getElementHandle( ) );
							provider.addFilter( new ComputedColumnExpressionFilter( bindingTable ) );
							expressionCellEditor.setExpressionProvider( provider );
						}
					}
				}
				updateButtons( );
			}
		} );
		btnAdd = new Button( contentComposite, SWT.PUSH );