How to work with onBeforeDelete and onAfterDelete?

In general, there are certain server related actions that die silently without any or only an limited error message to the front end. 

I am unsure why you get a "return true". It´s what a client side relationship Method would return, but I don´t remember right now. 

The most important thing you need to know about onBefore/AfterDelete is that you cannot use the regular context item (this). You don´t have a context item after deleting cause it´s obviously gone. And you only have a limited context item before deletion (only type + id).

A proven strategy is to pass the needed properties from the onBefore to the onAfter Method via a session state variable. 
See programmers guide: 8.26 How to Pass Values from onBeforeX to onAfterX Events.

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