that are now affixed to _MapperConfig - declarative now creates column copies ahead of time so that they are ready to go for a declared_attr - overhaul of declared_attr; memoization, cascading modifier - A relationship set up with :class:`.declared_attr` on a :class:`.AbstractConcreteBase` base class will now be configured on the abstract base mapping automatically, in addition to being set up on descendant concrete classes as usual. fixes #2670 - The :class:`.declared_attr` construct has newly improved behaviors and features in conjunction with declarative. The decorated function will now have access to the final column copies present on the local mixin when invoked, and will also be invoked exactly once for each mapped class, the returned result being memoized. A new modifier :attr:`.declared_attr.cascading` is added as well. fixes #3150 - the original plan for #3150 has been scaled back; by copying mixin columns up front and memoizing, we don't actually need the "map properties later" thing. - full docs + migration notes
to get all flake8 passing
distinguished for when it was actually the value ``False``. The ``__abstract__`` flag needs to acutally evaluate to a True value at the level being tested. fixes #3097
mixin or abstract class when accessed, so that modifications made to this dictionary by declarative itself won't conflict with that of other mappings. The dictionary is modified regarding the ``version_id_col`` and ``polymorphic_on`` arguments, replacing the column within with the one that is officially mapped to the local class/table. fixes #3062
fully usable within declarative relationship configuration, as its string classname would not be available in the registry of classnames at mapper configuration time. The class now explicitly adds itself to the class regsitry, and additionally both :class:`.AbstractConcreteBase` as well as :class:`.ConcreteBase` set themselves up *before* mappers are configured within the :func:`.configure_mappers` setup, using the new :meth:`.MapperEvents.before_configured` event. [ticket:2950] - Added new :meth:`.MapperEvents.before_configured` event which allows an event at the start of :func:`.configure_mappers`, as well as ``__declare_first__()`` hook within declarative to complement ``__declare_last__()``. - modified how after_configured is invoked; we just make a dispatch() not actually connected to any mapper. this makes it easier to also invoke before_configured correctly. - improved the ComparableEntity fixture to handle collections that are sets.
new automap extension would fail if classes were pre-arranged in single or potentially joined inheritance patterns. The repaired joined inheritance issue could also potentially apply when using :class:`.DeferredReflection` as well.
:class:`.DeferredReflection` to define classes pending for reflection, if some subset of those classes were discarded before the :meth:`.DeferredReflection.prepare` method were called to reflect and map the class, a strong reference to the class would remain held within the declarative internals. This internal collection of "classes to map" now uses weak references against the classes themselves.