a column setup on the ABC base which had a different attribute name vs. column name would not be correctly mapped on the final base class. The failure on 0.9 would be silent whereas on 1.0 it raised an ArgumentError, so may not have been noticed prior to 1.0. fixes #3480
event where its invocation was moved to be after the class manager's instrumentation of the class, which is the opposite of what the documentation for the event explicitly states. The rationale for the switch was due to Declarative taking the step of setting up the full "instrumentation manager" for a class before it was mapped for the purpose of the new ``@declared_attr`` features described in :ref:`feature_3150`, but the change was also made against the classical use of :func:`.mapper` for consistency. However, SQLSoup relies upon the instrumentation event happening before any instrumentation under classical mapping. The behavior is reverted in the case of classical and declarative mapping, the latter implemented by using a simple memoization without using class manager. fixes #3388
and ``__declare_last__`` accessors where these would no longer be called on the superclass of the declarative base. fixes #3383
and :class:`.CheckConstraint` has been further enhanced such that when the constraint is associated with non-table-bound :class:`.Column` objects, the constraint will set up event listeners with the columns themselves such that the constraint auto attaches at the same time the columns are associated with the table. This in particular helps in some edge cases in declarative but is also of general use. fixes #3341
objects, such that they were prevented from being called outside of the declarative process; this is related to the enhancements of #3150 which allow ``@declared_attr`` to return a value that is cached based on the current class as it's being configured. The exception raise has been removed, and the behavior changed so that outside of the declarative process, the function decorated by ``@declared_attr`` is called every time just like a regular ``@property``, without using any caching, as none is available at this stage. fixes #3331
of a declarative inheritance hierarchy would prevent attributes and configuration being correctly propagated from the base class to the inheriting class. fixes #3219 fixes #3240
subclass, the value returned by the descriptor is not available because the superclass is already mapped with the InstrumentedAttribute, until the subclass is mapped. We add a setattr() to set up that attribute so that the __mapper_args__ hook and possibly others have access to the "cascaded" version of the attribute within the call.
when using :class:`.AbstractConcreteBase` in conjunction with a subclass that declares ``__abstract__``. fixes #3185
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