Possible Usecases
There are many usecases for external callbacks,
including:
- cascaded deletes, updates
- referential integrity checks
- gathering statistics
- autoassigned fields
- assigning customary unique IDs for external referencing
- delayed deletion (objects are marked for deletion when
delete(object) is called and cleaned out of database in a later maintenance
operation)
- ensuring object fields uniqueness within the same class
etc.