diff --git a/django/core/apps/base.py b/django/core/apps/base.py
index 2503d9e3ff..706ed54ef6 100644
--- a/django/core/apps/base.py
+++ b/django/core/apps/base.py
@@ -1,6 +1,7 @@
from importlib import import_module
-from django.utils.module_loading import module_has_submodule
+from django.core.exceptions import ImproperlyConfigured
+from django.utils.module_loading import import_by_path, module_has_submodule
from django.utils._os import upath
@@ -14,16 +15,33 @@ class AppConfig(object):
def __init__(self, app_name):
# Full Python path to the application eg. 'django.contrib.admin'.
- # This is the value that appears in INSTALLED_APPS.
self.name = app_name
+ # Root module for the application eg. <module 'django.contrib.admin'
+ # from 'django/contrib/admin/__init__.pyc'>.
+ self.app_module = import_module(app_name)
+
+ # The following attributes could be defined at the class level in a
+ # subclass, hence the test-and-set pattern.
+
# Last component of the Python path to the application eg. 'admin'.
# This value must be unique across a Django project.
- self.label = app_name.rpartition(".")[2]
+ if not hasattr(self, 'label'):
+ self.label = app_name.rpartition(".")[2]
- # Root module eg. <module 'django.contrib.admin' from
- # 'django/contrib/admin/__init__.pyc'>.
- self.app_module = import_module(app_name)
+ # Human-readable name for the application eg. "Admin".
+ if not hasattr(self, 'verbose_name'):
+ self.verbose_name = self.label.title()
+
+ # Filesystem path to the application directory eg.
+ # u'/usr/lib/python2.7/dist-packages/django/contrib/admin'. May be
+ # None if the application isn't a bona fide package eg. if it's an
+ # egg. Otherwise it's a unicode on Python 2 and a str on Python 3.
+ if not hasattr(self, 'path'):
+ try:
+ self.path = upath(self.app_module.__path__[0])
+ except AttributeError:
+ self.path = None
# Module containing models eg. <module 'django.contrib.admin.models'
# from 'django/contrib/admin/models.pyc'>. Set by import_models().
@@ -34,18 +52,49 @@ class AppConfig(object):
# None to prevent accidental access before import_models() runs.
self.models = None
- # Filesystem path to the application directory eg.
- # u'/usr/lib/python2.7/dist-packages/django/contrib/admin'. May be
- # None if the application isn't a bona fide package eg. if it's an
- # egg. Otherwise it's a unicode on Python 2 and a str on Python 3.
- try:
- self.path = upath(self.app_module.__path__[0])
- except AttributeError:
- self.path = None
-
def __repr__(self):
return '<AppConfig: %s>' % self.label
+ @classmethod
+ def create(cls, entry):
+ """
+ Factory that creates an app config from an entry in INSTALLED_APPS.
+ """
+ try:
+ # If import_module succeeds, entry is a path to an app module.
+ # Otherwise, entry is a path to an app config class or an error.
+ import_module(entry)
+
+ except ImportError:
+ # Raise the original exception when entry cannot be a path to an
+ # app config class. Since module names are allowable here, the
+ # standard exception message from import_by_path is unsuitable.
+ if '.' not in entry:
+ raise
+
+ cls = import_by_path(entry)
+
+ # Check for obvious errors. (This check prevents duck typing, but
+ # it could be removed if it became a problem in practice.)
+ if not issubclass(cls, AppConfig):
+ raise ImproperlyConfigured(
+ "%r isn't a subclass of AppConfig." % entry)
+
+ # Obtain app name here rather than in AppClass.__init__ to keep
+ # all error checking for entries in INSTALLED_APPS in one place.
+ try:
+ app_name = cls.name
+ except AttributeError:
+ raise ImproperlyConfigured(
+ "%r must supply a name attribute." % entry)
+
+ # Entry is a path to an app config class.
+ return cls(app_name)
+
+ else:
+ # Entry is a path to an app module.
+ return cls(entry)
+
def import_models(self, all_models):
# Dictionary of models for this app, stored in the 'all_models'
# attribute of the AppCache this AppConfig is attached to. Injected as
diff --git a/django/core/apps/cache.py b/django/core/apps/cache.py
index 92b9f8d8d4..056aa9a60b 100644
--- a/django/core/apps/cache.py
+++ b/django/core/apps/cache.py
@@ -83,7 +83,7 @@ class AppCache(object):
# especially not other application modules, even indirectly.
# Therefore we simply import them sequentially.
for app_name in settings.INSTALLED_APPS:
- app_config = AppConfig(app_name)
+ app_config = AppConfig.create(app_name)
self.app_configs[app_config.label] = app_config
self._apps_loaded = True
@@ -347,7 +347,7 @@ class AppCache(object):
def _begin_with_app(self, app_name):
# Returns an opaque value that can be passed to _end_with_app().
- app_config = AppConfig(app_name)
+ app_config = AppConfig.create(app_name)
if app_config.label in self.app_configs:
return None
else:
@@ -412,7 +412,7 @@ class AppCache(object):
warnings.warn(
"load_app(app_name) is deprecated.",
PendingDeprecationWarning, stacklevel=2)
- app_config = AppConfig(app_name)
+ app_config = AppConfig.create(app_name)
app_config.import_models(self.all_models[app_config.label])
self.app_configs[app_config.label] = app_config
return app_config.models_module
diff --git a/tests/test_runner/tests.py b/tests/test_runner/tests.py
index a6dbeb0ae4..3c365b0225 100644
--- a/tests/test_runner/tests.py
+++ b/tests/test_runner/tests.py
@@ -226,7 +226,7 @@ class ModulesTestsPackages(IgnoreAllDeprecationWarningsMixin, unittest.TestCase)
"Check that the get_tests helper function can find tests in a directory"
from django.core.apps.base import AppConfig
from django.test.simple import get_tests
- app_config = AppConfig('test_runner.valid_app')
+ app_config = AppConfig.create('test_runner.valid_app')
app_config.import_models({})
tests = get_tests(app_config)
self.assertIsInstance(tests, types.ModuleType)
@@ -235,7 +235,7 @@ class ModulesTestsPackages(IgnoreAllDeprecationWarningsMixin, unittest.TestCase)
"Test for #12658 - Tests with ImportError's shouldn't fail silently"
from django.core.apps.base import AppConfig
from django.test.simple import get_tests
- app_config = AppConfig('test_runner_invalid_app')
+ app_config = AppConfig.create('test_runner_invalid_app')
app_config.import_models({})
with self.assertRaises(ImportError):
get_tests(app_config)