Moved the lookup in Field.swappable_setting to Apps, and added
an lru_cache to cache the results.
Refs #24743
Thanks Marten Kenbeek for the initial work on the patch. Thanks Aymeric
Augustin and Tim Graham for the review.
This adds a new method, Apps.lazy_model_operation(), and a helper function,
lazy_related_operation(), which together supersede add_lazy_relation() and
make lazy model operations the responsibility of the App registry. This
system no longer uses the class_prepared signal.
Set apps.ready to False when rendering multiple models. This prevents
that the cache on Model._meta is expired on all models after each time a
single model is rendered. Prevented that Apps.clear_cache() refills the
cache on Apps.get_models(), so that the wrong value cannot be cached
when cloning a StateApps.
Previously a RuntimeError was raised every time two models clashed
in the app registry. This prevented reloading a module in a REPL;
while it's not recommended to do so, we decided not to forbid this
use-case by turning the error into a warning.
Thanks @dfunckt and Sergey Pashinin for the initial patches.
Wherever possible this filesystem path is derived automatically from the app
module's ``__path__`` and ``__file__`` attributes (this avoids any
backwards-compatibility problems).
AppConfig allows specifying an app's filesystem location explicitly, which
overrides all autodetection based on ``__path__`` and ``__file__``. This
permits Django to support any type of module as an app (namespace packages,
fake modules, modules loaded by other hypothetical non-filesystem module
loaders), as long as the app is configured with an explicit filesystem path.
Thanks Aymeric for review and discussion.
Also document the conditions under which a namespace package may or may not be
a Django app, and raise a clearer error message in those cases where it may not
be.
Thanks Aymeric for review and consultation.
Since the app registry is always populated before the first request is
processed, the situation described in #18251 for the old app cache
cannot happen any more.
Refs #18251, #21628.
Now that the refactorings are complete, it isn't particularly useful any
more, nor very well named. Let's keep the API as simple as possible.
Fixed#21689.
To the best of my understanding, since populate_models() is now called
as soon as Django starts, it cannot be called while a models module is
being imported, and that removes the need for postponing.
(If hell breaks loose we'll revert this commit.)
Refs #21681.
Since it triggers imports, it shouldn't be done lightly.
This commit adds a public API for doing it explicitly, django.setup(),
and does it automatically when using manage.py and wsgi.py.