|
``repoze.bfg.location.ClassAndInstanceDescr`` class have both been
removed in order to be able to eventually shed a dependency on
``zope.proxy``. Neither of these classes was ever an API.
- In all previous releases, the ``repoze.bfg.location.locate``
function worked like so: if a model did not explicitly provide the
``repoze.bfg.interfaces.ILocation`` interface, ``locate`` returned a
``LocationProxy`` object representing ``model`` with its
``__parent__`` attribute assigned to ``parent`` and a ``__name__``
attribute assigned to ``__name__``. In this release, the
``repoze.bfg.location.locate`` function simply jams the ``__name__``
and ``__parent__`` attributes on to the supplied model
unconditionally, no matter if the object implements ILocation or
not, and it never returns a proxy. This was done because the
LocationProxy behavior has now moved into an add-on package
(``repoze.bfg.traversalwrapper``), in order to eventually be able to
shed a dependency on ``zope.proxy``.
- In all previous releases, by default, if traversal was used (as
opposed to URL-dispatch), and the root object supplied
the``repoze.bfg.interfaces.ILocation`` interface, but the children
returned via its ``__getitem__`` returned an object that did not
implement the same interface, :mod:`repoze.bfg` provided some
implicit help during traversal. This traversal feature wrapped
subobjects from the root (and thereafter) that did not implement
``ILocation`` in proxies which automatically provided them with a
``__name__`` and ``__parent__`` attribute based on the name being
traversed and the previous object traversed. This feature has now
been removed from the base ``repoze.bfg`` package for purposes of
eventually shedding a dependency on ``zope.proxy``.
In order to re-enable the wrapper behavior for older applications
which cannot be changed, register the "traversalwrapper"
``ModelGraphTraverser`` as the traversal policy, rather than the
default ``ModelGraphTraverser``. To use this feature, you will need
to install the ``repoze.bfg.traversalwrapper`` package (an add-on
package, available at
http://svn.repoze.org/repoze.bfg.traversalwrapper) Then change your
application's ``configure.zcml`` to include the following stanza:
<adapter
factory="repoze.bfg.traversalwrapper.ModelGraphTraverser"
provides="repoze.bfg.interfaces.ITraverserFactory"
for="*"
/>
When this ITraverserFactory is used instead of the default, no
object in the graph (even the root object) must supply a
``__name__`` or ``__parent__`` attribute. Even if subobjects
returned from the root *do* implement the ILocation interface,
these will still be wrapped in proxies that override the object's
"real" ``__parent__`` and ``__name__`` attributes.
See also changes to the "Models" chapter of the documentation (in
the "Location-Aware Model Instances") section.
|
