Basically each of the CRUD operations that you mentioned should return as response the updated/created/delete object (this is done with the corresponding Dao method). Check the example here:
In the cases above the requestEnd
dataSource event will be triggered and you can signify success.
In case there is any error
the error event of the dataSource will be triggered and you can warn the users that something has gone wrong.
Join us on our journey to create the world's most complete HTML 5 UI Framework - download Kendo UI