diff options
Diffstat (limited to 'lib/sqlalchemy/orm/events.py')
| -rw-r--r-- | lib/sqlalchemy/orm/events.py | 127 |
1 files changed, 71 insertions, 56 deletions
diff --git a/lib/sqlalchemy/orm/events.py b/lib/sqlalchemy/orm/events.py index 0e08a0898..aa99673ba 100644 --- a/lib/sqlalchemy/orm/events.py +++ b/lib/sqlalchemy/orm/events.py @@ -18,6 +18,7 @@ from .session import Session, sessionmaker from .scoping import scoped_session from .attributes import QueryableAttribute + class InstrumentationEvents(event.Events): """Events related to class instrumentation events. @@ -50,7 +51,6 @@ class InstrumentationEvents(event.Events): _target_class_doc = "SomeBaseClass" _dispatch_target = instrumentation.InstrumentationFactory - @classmethod def _accept_with(cls, target): if isinstance(target, type): @@ -71,10 +71,11 @@ class InstrumentationEvents(event.Events): return fn(target_cls, *arg) def remove(ref): - key = event.registry._EventKey(None, identifier, listen, - instrumentation._instrumentation_factory) + key = event.registry._EventKey( + None, identifier, listen, + instrumentation._instrumentation_factory) getattr(instrumentation._instrumentation_factory.dispatch, - identifier).remove(key) + identifier).remove(key) target = weakref.ref(target.class_, remove) @@ -107,17 +108,18 @@ class InstrumentationEvents(event.Events): """Called when an attribute is instrumented.""" - class _InstrumentationEventsHold(object): """temporary marker object used to transfer from _accept_with() to _listen() on the InstrumentationEvents class. """ + def __init__(self, class_): self.class_ = class_ dispatch = event.dispatcher(InstrumentationEvents) + class InstanceEvents(event.Events): """Define events specific to object lifecycle. @@ -201,7 +203,8 @@ class InstanceEvents(event.Events): if propagate: for mgr in target.subclass_managers(True): - event_key.with_dispatch_target(mgr).base_listen(propagate=True) + event_key.with_dispatch_target(mgr).base_listen( + propagate=True) @classmethod def _clear(cls): @@ -330,6 +333,7 @@ class InstanceEvents(event.Events): """ + class _EventsHold(event.RefCollection): """Hold onto listeners against unmapped, uninstrumented classes. @@ -337,6 +341,7 @@ class _EventsHold(event.RefCollection): those objects are created for that class. """ + def __init__(self, class_): self.class_ = class_ @@ -387,9 +392,9 @@ class _EventsHold(event.RefCollection): collection = cls.all_holds[subclass] for event_key, raw, propagate in collection.values(): if propagate or subclass is class_: - # since we can't be sure in what order different classes - # in a hierarchy are triggered with populate(), - # we rely upon _EventsHold for all event + # since we can't be sure in what order different + # classes in a hierarchy are triggered with + # populate(), we rely upon _EventsHold for all event # assignment, instead of using the generic propagate # flag. event_key.with_dispatch_target(subject).\ @@ -502,16 +507,17 @@ class MapperEvents(event.Events): return target @classmethod - def _listen(cls, event_key, raw=False, retval=False, propagate=False, **kw): + def _listen( + cls, event_key, raw=False, retval=False, propagate=False, **kw): target, identifier, fn = \ event_key.dispatch_target, event_key.identifier, event_key.fn if identifier in ("before_configured", "after_configured") and \ - target is not mapperlib.Mapper: + target is not mapperlib.Mapper: util.warn( - "'before_configured' and 'after_configured' ORM events " - "only invoke with the mapper() function or Mapper class " - "as the target.") + "'before_configured' and 'after_configured' ORM events " + "only invoke with the mapper() function or Mapper class " + "as the target.") if not raw or not retval: if not raw: @@ -536,7 +542,7 @@ class MapperEvents(event.Events): if propagate: for mapper in target.self_and_descendants: event_key.with_dispatch_target(mapper).base_listen( - propagate=True, **kw) + propagate=True, **kw) else: event_key.base_listen(**kw) @@ -722,7 +728,7 @@ class MapperEvents(event.Events): """ def append_result(self, mapper, context, row, target, - result, **flags): + result, **flags): """Receive an object instance before that instance is appended to a result list. @@ -759,7 +765,7 @@ class MapperEvents(event.Events): """ def populate_instance(self, mapper, context, row, - target, **flags): + target, **flags): """Receive an instance before that instance has its attributes populated. @@ -1165,6 +1171,7 @@ class MapperEvents(event.Events): """ + class _MapperEventsHold(_EventsHold): all_holds = weakref.WeakKeyDictionary() @@ -1215,11 +1222,11 @@ class SessionEvents(event.Events): ( not isinstance(target, type) or not issubclass(target, Session) - ): + ): raise exc.ArgumentError( - "Session event listen on a scoped_session " - "requires that its creation callable " - "is associated with the Session class.") + "Session event listen on a scoped_session " + "requires that its creation callable " + "is associated with the Session class.") if isinstance(target, sessionmaker): return target.class_ @@ -1284,8 +1291,10 @@ class SessionEvents(event.Events): The :meth:`~.SessionEvents.before_commit` hook is *not* per-flush, that is, the :class:`.Session` can emit SQL to the database many times within the scope of a transaction. - For interception of these events, use the :meth:`~.SessionEvents.before_flush`, - :meth:`~.SessionEvents.after_flush`, or :meth:`~.SessionEvents.after_flush_postexec` + For interception of these events, use the + :meth:`~.SessionEvents.before_flush`, + :meth:`~.SessionEvents.after_flush`, or + :meth:`~.SessionEvents.after_flush_postexec` events. :param session: The target :class:`.Session`. @@ -1310,16 +1319,19 @@ class SessionEvents(event.Events): The :meth:`~.SessionEvents.after_commit` hook is *not* per-flush, that is, the :class:`.Session` can emit SQL to the database many times within the scope of a transaction. - For interception of these events, use the :meth:`~.SessionEvents.before_flush`, - :meth:`~.SessionEvents.after_flush`, or :meth:`~.SessionEvents.after_flush_postexec` + For interception of these events, use the + :meth:`~.SessionEvents.before_flush`, + :meth:`~.SessionEvents.after_flush`, or + :meth:`~.SessionEvents.after_flush_postexec` events. .. note:: The :class:`.Session` is not in an active transaction - when the :meth:`~.SessionEvents.after_commit` event is invoked, and therefore - can not emit SQL. To emit SQL corresponding to every transaction, - use the :meth:`~.SessionEvents.before_commit` event. + when the :meth:`~.SessionEvents.after_commit` event is invoked, + and therefore can not emit SQL. To emit SQL corresponding to + every transaction, use the :meth:`~.SessionEvents.before_commit` + event. :param session: The target :class:`.Session`. @@ -1467,8 +1479,8 @@ class SessionEvents(event.Events): This is called before an add, delete or merge causes the object to be part of the session. - .. versionadded:: 0.8. Note that :meth:`~.SessionEvents.after_attach` now - fires off after the item is part of the session. + .. versionadded:: 0.8. Note that :meth:`~.SessionEvents.after_attach` + now fires off after the item is part of the session. :meth:`.before_attach` is provided for those cases where the item should not yet be part of the session state. @@ -1501,12 +1513,12 @@ class SessionEvents(event.Events): """ @event._legacy_signature("0.9", - ["session", "query", "query_context", "result"], - lambda update_context: ( - update_context.session, - update_context.query, - update_context.context, - update_context.result)) + ["session", "query", "query_context", "result"], + lambda update_context: ( + update_context.session, + update_context.query, + update_context.context, + update_context.result)) def after_bulk_update(self, update_context): """Execute after a bulk update operation to the session. @@ -1516,8 +1528,8 @@ class SessionEvents(event.Events): details about the update, including these attributes: * ``session`` - the :class:`.Session` involved - * ``query`` -the :class:`.Query` object that this update operation was - called upon. + * ``query`` -the :class:`.Query` object that this update operation + was called upon. * ``context`` The :class:`.QueryContext` object, corresponding to the invocation of an ORM query. * ``result`` the :class:`.ResultProxy` returned as a result of the @@ -1527,12 +1539,12 @@ class SessionEvents(event.Events): """ @event._legacy_signature("0.9", - ["session", "query", "query_context", "result"], - lambda delete_context: ( - delete_context.session, - delete_context.query, - delete_context.context, - delete_context.result)) + ["session", "query", "query_context", "result"], + lambda delete_context: ( + delete_context.session, + delete_context.query, + delete_context.context, + delete_context.result)) def after_bulk_delete(self, delete_context): """Execute after a bulk delete operation to the session. @@ -1542,8 +1554,8 @@ class SessionEvents(event.Events): details about the update, including these attributes: * ``session`` - the :class:`.Session` involved - * ``query`` -the :class:`.Query` object that this update operation was - called upon. + * ``query`` -the :class:`.Query` object that this update operation + was called upon. * ``context`` The :class:`.QueryContext` object, corresponding to the invocation of an ORM query. * ``result`` the :class:`.ResultProxy` returned as a result of the @@ -1628,8 +1640,8 @@ class AttributeEvents(event.Events): @classmethod def _listen(cls, event_key, active_history=False, - raw=False, retval=False, - propagate=False): + raw=False, retval=False, + propagate=False): target, identifier, fn = \ event_key.dispatch_target, event_key.identifier, event_key.fn @@ -1654,7 +1666,8 @@ class AttributeEvents(event.Events): manager = instrumentation.manager_of_class(target.class_) for mgr in manager.subclass_managers(True): - event_key.with_dispatch_target(mgr[target.key]).base_listen(propagate=True) + event_key.with_dispatch_target( + mgr[target.key]).base_listen(propagate=True) def append(self, target, value, initiator): """Receive a collection append event. @@ -1672,8 +1685,9 @@ class AttributeEvents(event.Events): chained event propagation. .. versionchanged:: 0.9.0 the ``initiator`` argument is now - passed as a :class:`.attributes.Event` object, and may be modified - by backref handlers within a chain of backref-linked events. + passed as a :class:`.attributes.Event` object, and may be + modified by backref handlers within a chain of backref-linked + events. :return: if the event was registered with ``retval=True``, the given value, or a new effective value, should be returned. @@ -1693,8 +1707,9 @@ class AttributeEvents(event.Events): chained event propagation. .. versionchanged:: 0.9.0 the ``initiator`` argument is now - passed as a :class:`.attributes.Event` object, and may be modified - by backref handlers within a chain of backref-linked events. + passed as a :class:`.attributes.Event` object, and may be + modified by backref handlers within a chain of backref-linked + events. :return: No return value is defined for this event. """ @@ -1721,11 +1736,11 @@ class AttributeEvents(event.Events): chained event propagation. .. versionchanged:: 0.9.0 the ``initiator`` argument is now - passed as a :class:`.attributes.Event` object, and may be modified - by backref handlers within a chain of backref-linked events. + passed as a :class:`.attributes.Event` object, and may be + modified by backref handlers within a chain of backref-linked + events. :return: if the event was registered with ``retval=True``, the given value, or a new effective value, should be returned. """ - |