133 alternative method to schedule an operation from a hook, using the

   133 alternative method to schedule an operation from a hook, using the

   134 :func:`get_instance` class method.

   134 :func:`get_instance` class method.

   135 

   135 

   136 .. sourcecode:: python

   136 .. sourcecode:: python

   137 

   137 

   140    class CheckSubsidiaryCycleHook(Hook):

   138    class CheckSubsidiaryCycleHook(Hook):

   141        __regid__ = 'check_no_subsidiary_cycle'

   139        __regid__ = 'check_no_subsidiary_cycle'

   142        events = ('after_add_relation',)

   140        events = ('after_add_relation',)

   143        __select__ = Hook.__select__ & match_rtype('subsidiary_of')

   141        __select__ = Hook.__select__ & match_rtype('subsidiary_of')

   144 

   142 

   150        def precommit_event(self):

   148        def precommit_event(self):

   151            for eid in self.get_data():

   149            for eid in self.get_data():

   152                check_cycle(self.session, eid, self.rtype)

   150                check_cycle(self.session, eid, self.rtype)

   153 

   151 

   154 

   152 

   156 entities to check at the end in a single `CheckSubsidiaryCycleOp`

   154 entities to check at the end in a single `CheckSubsidiaryCycleOp`

   157 operation. Values are stored in a set associated to the

   155 operation. Values are stored in a set associated to the

   158 'subsidiary_cycle_detection' transaction data key. The set initialization and

   156 'subsidiary_cycle_detection' transaction data key. The set initialization and

   160 

   158 

   161 A more realistic example can be found in the advanced tutorial chapter

   159 A more realistic example can be found in the advanced tutorial chapter

   162 :ref:`adv_tuto_security_propagation`.

   160 :ref:`adv_tuto_security_propagation`.

   163 

   161 

   164 

   162