@staticmethod
    def case_event_ondelete(row):
        """
            Actions after deleting a case event:
                - update last_seen_on in the corresponding cases

            @param row: the deleted Row
        """

        # Get the deleted keys
        table = current.s3db.dvr_case_event
        row = current.db(table.id == row.id).select(table.deleted_fk,
                                                    limitby = (0, 1),
                                                    ).first()
        if row and row.deleted_fk:

            # Get the person ID
            try:
                deleted_fk = json.loads(row.deleted_fk)
            except (__HOLE__, TypeError):
                person_id = None
            else:
                person_id = deleted_fk.get("person_id")

            # Update last_seen_on
            if person_id:
                dvr_update_last_seen(person_id)

# =============================================================================
dataset/ETHPy150Open sahana/eden/modules/s3db/dvr.py/DVRCaseEventModel.case_event_ondelete