本文整理汇总了Python中sqlalchemy.orm.interfaces.MapperExtension方法的典型用法代码示例。如果您正苦于以下问题：Python interfaces.MapperExtension方法的具体用法？Python interfaces.MapperExtension怎么用？Python interfaces.MapperExtension使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类sqlalchemy.orm.interfaces的用法示例。
在下文中一共展示了interfaces.MapperExtension方法的10个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: reconstruct_instance
# 需要导入模块: from sqlalchemy.orm import interfaces [as 别名]
# 或者: from sqlalchemy.orm.interfaces import MapperExtension [as 别名]
def reconstruct_instance(self, mapper, instance):
"""Receive an object instance after it has been created via
``__new__``, and after initial attribute population has
occurred.
This typically occurs when the instance is created based on
incoming result rows, and is only called once for that
instance's lifetime.
Note that during a result-row load, this method is called upon
the first row received for this instance. Note that some
attributes and collections may or may not be loaded or even
initialized, depending on what's present in the result rows.
The return value is only significant within the ``MapperExtension``
chain; the parent mapper's behavior isn't modified by this method.
"""
return EXT_CONTINUE 示例2: _adapt_listener_methods
# 需要导入模块: from sqlalchemy.orm import interfaces [as 别名]
# 或者: from sqlalchemy.orm.interfaces import MapperExtension [as 别名]
def _adapt_listener_methods(cls, self, listener, methods):
for meth in methods:
me_meth = getattr(MapperExtension, meth)
ls_meth = getattr(listener, meth)
if not util.methods_equivalent(me_meth, ls_meth):
if meth == 'reconstruct_instance':
def go(ls_meth):
def reconstruct(instance, ctx):
ls_meth(self, instance)
return reconstruct
event.listen(self.class_manager, 'load',
go(ls_meth), raw=False, propagate=True)
elif meth == 'init_instance':
def go(ls_meth):
def init_instance(instance, args, kwargs):
ls_meth(self, self.class_,
self.class_manager.original_init,
instance, args, kwargs)
return init_instance
event.listen(self.class_manager, 'init',
go(ls_meth), raw=False, propagate=True)
elif meth == 'init_failed':
def go(ls_meth):
def init_failed(instance, args, kwargs):
util.warn_exception(
ls_meth, self, self.class_,
self.class_manager.original_init,
instance, args, kwargs)
return init_failed
event.listen(self.class_manager, 'init_failure',
go(ls_meth), raw=False, propagate=True)
else:
event.listen(self, "%s" % meth, ls_meth,
raw=False, retval=True, propagate=True) 示例3: instrument_class
# 需要导入模块: from sqlalchemy.orm import interfaces [as 别名]
# 或者: from sqlalchemy.orm.interfaces import MapperExtension [as 别名]
def instrument_class(self, mapper, class_):
"""Receive a class when the mapper is first constructed, and has
applied instrumentation to the mapped class.
The return value is only significant within the ``MapperExtension``
chain; the parent mapper's behavior isn't modified by this method.
"""
return EXT_CONTINUE 示例4: init_instance
# 需要导入模块: from sqlalchemy.orm import interfaces [as 别名]
# 或者: from sqlalchemy.orm.interfaces import MapperExtension [as 别名]
def init_instance(self, mapper, class_, oldinit, instance, args, kwargs):
"""Receive an instance when its constructor is called.
This method is only called during a userland construction of
an object. It is not called when an object is loaded from the
database.
The return value is only significant within the ``MapperExtension``
chain; the parent mapper's behavior isn't modified by this method.
"""
return EXT_CONTINUE 示例5: init_failed
# 需要导入模块: from sqlalchemy.orm import interfaces [as 别名]
# 或者: from sqlalchemy.orm.interfaces import MapperExtension [as 别名]
def init_failed(self, mapper, class_, oldinit, instance, args, kwargs):
"""Receive an instance when its constructor has been called,
and raised an exception.
This method is only called during a userland construction of
an object. It is not called when an object is loaded from the
database.
The return value is only significant within the ``MapperExtension``
chain; the parent mapper's behavior isn't modified by this method.
"""
return EXT_CONTINUE 示例6: after_insert
# 需要导入模块: from sqlalchemy.orm import interfaces [as 别名]
# 或者: from sqlalchemy.orm.interfaces import MapperExtension [as 别名]
def after_insert(self, mapper, connection, instance):
"""Receive an object instance after that instance is inserted.
The return value is only significant within the ``MapperExtension``
chain; the parent mapper's behavior isn't modified by this method.
"""
return EXT_CONTINUE 示例7: before_update
# 需要导入模块: from sqlalchemy.orm import interfaces [as 别名]
# 或者: from sqlalchemy.orm.interfaces import MapperExtension [as 别名]
def before_update(self, mapper, connection, instance):
"""Receive an object instance before that instance is updated.
Note that this method is called for all instances that are marked as
"dirty", even those which have no net changes to their column-based
attributes. An object is marked as dirty when any of its column-based
attributes have a "set attribute" operation called or when any of its
collections are modified. If, at update time, no column-based
attributes have any net changes, no UPDATE statement will be issued.
This means that an instance being sent to before_update is *not* a
guarantee that an UPDATE statement will be issued (although you can
affect the outcome here).
To detect if the column-based attributes on the object have net
changes, and will therefore generate an UPDATE statement, use
``object_session(instance).is_modified(instance,
include_collections=False)``.
Column-based attributes can be modified within this method
which will result in the new value being updated. However
*no* changes to the overall flush plan can be made, and
manipulation of the ``Session`` will not have the desired effect.
To manipulate the ``Session`` within an extension, use
``SessionExtension``.
The return value is only significant within the ``MapperExtension``
chain; the parent mapper's behavior isn't modified by this method.
"""
return EXT_CONTINUE 示例8: after_update
# 需要导入模块: from sqlalchemy.orm import interfaces [as 别名]
# 或者: from sqlalchemy.orm.interfaces import MapperExtension [as 别名]
def after_update(self, mapper, connection, instance):
"""Receive an object instance after that instance is updated.
The return value is only significant within the ``MapperExtension``
chain; the parent mapper's behavior isn't modified by this method.
"""
return EXT_CONTINUE 示例9: before_delete
# 需要导入模块: from sqlalchemy.orm import interfaces [as 别名]
# 或者: from sqlalchemy.orm.interfaces import MapperExtension [as 别名]
def before_delete(self, mapper, connection, instance):
"""Receive an object instance before that instance is deleted.
Note that *no* changes to the overall flush plan can be made
here; and manipulation of the ``Session`` will not have the
desired effect. To manipulate the ``Session`` within an
extension, use ``SessionExtension``.
The return value is only significant within the ``MapperExtension``
chain; the parent mapper's behavior isn't modified by this method.
"""
return EXT_CONTINUE 示例10: after_delete
# 需要导入模块: from sqlalchemy.orm import interfaces [as 别名]
# 或者: from sqlalchemy.orm.interfaces import MapperExtension [as 别名]
def after_delete(self, mapper, connection, instance):
"""Receive an object instance after that instance is deleted.
The return value is only significant within the ``MapperExtension``
chain; the parent mapper's behavior isn't modified by this method.
"""
return EXT_CONTINUE