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
public Object getValue( Object element, String property )
		{
			if ( element == dummyChoice )
			{
				ComputedColumn column = StructureFactory.newComputedColumn( inputElement,
						DEFAULT_COLUMN_NAME );
				column.setExpression( "" ); 
				String groupType = DEUtil.getGroupControlType( inputElement );
				if ( ExpressionUtil.hasAggregation( column.getExpression( ) ) )
				{
					if ( groupType.equals( DEUtil.TYPE_GROUP_GROUP ) )
						column.setAggregrateOn( ( (GroupHandle) DEUtil.getGroups( inputElement )
								.get( 0 ) ).getName( ) );
					else if ( groupType.equals( DEUtil.TYPE_GROUP_LISTING ) )
						column.setAggregrateOn( null );
				}
				if ( !ExpressionUtil.hasAggregation( column.getExpression( ) )
						|| groupType.equals( DEUtil.TYPE_GROUP_NONE ) )
				{
					column.setAggregrateOn( null );
				}
				addBinding( column );
				highLightName = column.getName( );
				return ""; 
			}
			ComputedColumnHandle handle = ( (ComputedColumnHandle) element );
			String value = null;
			if ( COLUMN_NAME.equals( property ) )
			{
				value = handle.getName( );