Following the app-loading refactor, these objects must live outside of
django.contrib.sites.models because they must be available without
importing the django.contrib.sites.models module when
django.contrib.sites isn't installed.
Refs #21680. Thanks Carl and Loic for reporting this issue.
Since applications that aren't installed no longer have an application
configuration, it is now always True in practice.
Provided an abstraction to temporarily add or remove applications as
several tests messed with app_config.installed to achieve this effect.
For now this API is _-prefixed because it looks dangerous.
Used the information from the app cache instead of creating a duplicate
based on INSTALLED_APPS.
Model._meta.installed is no longer writable. It was a rather sketchy way
to alter private internals anyway.
Many thanks to gabrielhurley for putting most of this together. Also to
bmihelac, arthurk, qingfeng, hvendelbo, petr.pulc@s-cape.cz, Hraban for
reports and some initial patches.
The patch also contains some whitespace/PEP8 fixes.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@13980 bcc190cf-cafb-0310-a4f2-bffc1f526a37
This avoids the problem of, for example, saving a change to the Site model in
the admin interface and then seeing the wrong instanec returned in the next
call to get_current_site().
It's still possible to end up with an inconsistent cache if update() is used to
change the Site model, but that's pretty unavoidable. It's also a slightly odd
way to update a Site model, so if you really need to do that, you can manage to
call SiteManager.clear() at the same time.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@9908 bcc190cf-cafb-0310-a4f2-bffc1f526a37