Module « sqlalchemy.orm »

Classe « InstanceEvents »

Informations générales

Héritage

builtins.object
    Events
        InstanceEvents

Définition

class InstanceEvents(Events):

Description _{[extrait de InstanceEvents.__doc__]}

Define events specific to object lifecycle.

    e.g.::

        from sqlalchemy import event

        def my_load_listener(target, context):
            print("on load!")

        event.listen(SomeClass, 'load', my_load_listener)

    Available targets include:

    * mapped classes
    * unmapped superclasses of mapped or to-be-mapped classes
      (using the ``propagate=True`` flag)
    * :class:`_orm.Mapper` objects
    * the :class:`_orm.Mapper` class itself and the :func:`.mapper`
      function indicate listening for all mappers.

    Instance events are closely related to mapper events, but
    are more specific to the instance and its instrumentation,
    rather than its system of persistence.

    When using :class:`.InstanceEvents`, several modifiers are
    available to the :func:`.event.listen` function.

    :param propagate=False: When True, the event listener should
       be applied to all inheriting classes as well as the
       class which is the target of this listener.
    :param raw=False: When True, the "target" argument passed
       to applicable event listener functions will be the
       instance's :class:`.InstanceState` management
       object, rather than the mapped instance itself.
    :param restore_load_context=False: Applies to the
       :meth:`.InstanceEvents.load` and :meth:`.InstanceEvents.refresh`
       events.  Restores the loader context of the object when the event
       hook is complete, so that ongoing eager load operations continue
       to target the object appropriately.  A warning is emitted if the
       object is moved to a new loader context from within one of these
       events if this flag is not set.

       .. versionadded:: 1.3.14


    

Constructeur(s)

Signature du constructeur	Description
__init__(self, /, *args, **kwargs)	Initialize self. See help(type(self)) for accurate signature. [extrait de __init__.__doc__]

Liste des opérateurs

Opérateurs hérités de la classe object

__eq__, __ge__, __gt__, __le__, __lt__, __ne__

Méthodes héritées de la classe Events

__init_subclass__, __subclasshook__

Méthodes héritées de la classe object

__delattr__, __dir__, __format__, __getattribute__, __hash__, __reduce__, __reduce_ex__, __repr__, __setattr__, __sizeof__, __str__