diff options
Diffstat (limited to 'lib/sqlalchemy/ext/mutable.py')
| -rw-r--r-- | lib/sqlalchemy/ext/mutable.py | 22 |
1 files changed, 9 insertions, 13 deletions
diff --git a/lib/sqlalchemy/ext/mutable.py b/lib/sqlalchemy/ext/mutable.py index d3133b1f5..82410031d 100644 --- a/lib/sqlalchemy/ext/mutable.py +++ b/lib/sqlalchemy/ext/mutable.py @@ -1,5 +1,5 @@ # ext/mutable.py -# Copyright (C) 2005-2013 the SQLAlchemy authors and contributors <see AUTHORS file> +# Copyright (C) 2005-2014 the SQLAlchemy authors and contributors <see AUTHORS file> # # This module is part of SQLAlchemy and is released under # the MIT License: http://www.opensource.org/licenses/mit-license.php @@ -7,13 +7,9 @@ """Provide support for tracking of in-place changes to scalar values, which are propagated into ORM change events on owning parent objects. -The :mod:`sqlalchemy.ext.mutable` extension replaces SQLAlchemy's legacy -approach to in-place mutations of scalar values, established by the -:class:`.types.MutableType` class as well as the ``mutable=True`` type flag, -with a system that allows change events to be propagated from the value to -the owning parent, thereby removing the need for the ORM to maintain copies -of values as well as the very expensive requirement of scanning through all -"mutable" values on each flush call, looking for changes. +.. versionadded:: 0.7 :mod:`sqlalchemy.ext.mutable` replaces SQLAlchemy's + legacy approach to in-place mutations of scalar values; see + :ref:`07_migration_mutation_extension`. .. _mutable_scalars: @@ -182,7 +178,7 @@ callbacks. In our case, this is a good thing, since if this dictionary were picklable, it could lead to an excessively large pickle size for our value objects that are pickled by themselves outside of the context of the parent. The developer responsibility here is only to provide a ``__getstate__`` method -that excludes the :meth:`~.MutableBase._parents` collection from the pickle +that excludes the :meth:`~MutableBase._parents` collection from the pickle stream:: class MyMutableType(Mutable): @@ -332,7 +328,7 @@ Supporting Pickling As is the case with :class:`.Mutable`, the :class:`.MutableComposite` helper class uses a ``weakref.WeakKeyDictionary`` available via the -:meth:`.MutableBase._parents` attribute which isn't picklable. If we need to +:meth:`MutableBase._parents` attribute which isn't picklable. If we need to pickle instances of ``Point`` or its owning class ``Vertex``, we at least need to define a ``__getstate__`` that doesn't include the ``_parents`` dictionary. Below we define both a ``__getstate__`` and a ``__setstate__`` that package up @@ -349,7 +345,7 @@ the minimal form of our ``Point`` class:: As with :class:`.Mutable`, the :class:`.MutableComposite` augments the pickling process of the parent's object-relational state so that the -:meth:`.MutableBase._parents` collection is restored to all ``Point`` objects. +:meth:`MutableBase._parents` collection is restored to all ``Point`` objects. """ from ..orm.attributes import flag_modified @@ -542,7 +538,7 @@ class Mutable(MutableBase): To associate a particular mutable type with all occurrences of a particular type, use the :meth:`.Mutable.associate_with` classmethod - of the particular :meth:`.Mutable` subclass to establish a global + of the particular :class:`.Mutable` subclass to establish a global association. .. warning:: @@ -595,7 +591,7 @@ def _setup_composite_listener(): issubclass(prop.composite_class, MutableComposite)): prop.composite_class._listen_on_attribute( getattr(class_, prop.key), False, class_) - if not Mapper.dispatch.mapper_configured._contains(Mapper, _listen_for_type): + if not event.contains(Mapper, "mapper_configured", _listen_for_type): event.listen(Mapper, 'mapper_configured', _listen_for_type) _setup_composite_listener() |