Deleting entities is very simple. Update the delete button MXML tag to call onDeleteClick() when clicked, and to only be enabled if there is a selection in the tree.
And implement the onDeleteClick() method:
Notice that we maintain the bi-directional association if the deleted item is a contact by removing it from its associated contactGroup.
And that’s it :) The entity will be removed from its entity repository (updating the tree via databinding) and on the next flush() it will be removed from the database.
The final step in our little address book is to allow the user to update existing entities.