GUIBaseContext :: doAfterCancelData - Data-cancelled event handler

The handler handles the data-canceled (DEV_Cancelled) event. When the event is fired, changes have already been canceled and the the instance in the property handle has been reset.

The event handler can be used in a transaction save dialog in order to roll back changes made and restart the transaction. In this case, the handler should call refresh() in order to update data displayed in the form.