Fixed #21877 -- Renamed django.apps.base to config.

1 files changed, 185 insertions, 0 deletions

diff --git a/django/apps/config.py b/django/apps/config.py
new file mode 100644
index 0000000000..e25178e25d
--- /dev/null
+++ b/django/apps/config.py
@@ -0,0 +1,185 @@
+from importlib import import_module
+
+from django.core.exceptions import ImproperlyConfigured
+from django.utils.module_loading import module_has_submodule
+from django.utils._os import upath
+
+
+MODELS_MODULE_NAME = 'models'
+
+
+class AppConfig(object):
+    """
+    Class representing a Django application and its configuration.
+    """
+
+    def __init__(self, app_name, app_module):
+        # Full Python path to the application eg. 'django.contrib.admin'.
+        self.name = app_name
+
+        # Root module for the application eg. <module 'django.contrib.admin'
+        # from 'django/contrib/admin/__init__.pyc'>.
+        self.module = app_module
+
+        # 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.
+        if not hasattr(self, 'label'):
+            self.label = app_name.rpartition(".")[2]
+
+        # 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:
+                paths = app_module.__path__
+            except AttributeError:
+                self.path = None
+            else:
+                # Convert paths to list because Python 3.3 _NamespacePath does
+                # not support indexing.
+                paths = list(paths)
+                if len(paths) > 1:
+                    raise ImproperlyConfigured(
+                        "The namespace package app %r has multiple locations, "
+                        "which is not supported: %r" % (app_name, paths))
+                self.path = upath(paths[0])
+
+        # Module containing models eg. <module 'django.contrib.admin.models'
+        # from 'django/contrib/admin/models.pyc'>. Set by import_models().
+        # None if the application doesn't have a models module.
+        self.models_module = None
+
+        # Mapping of lower case model names to model classes. Initally set to
+        # None to prevent accidental access before import_models() runs.
+        self.models = None
+
+    def __repr__(self):
+        return '<%s: %s>' % (self.__class__.__name__, 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,
+            # which may specify an app config class with default_app_config.
+            # Otherwise, entry is a path to an app config class or an error.
+            module = import_module(entry)
+
+        except ImportError:
+            mod_path, _, cls_name = entry.rpartition('.')
+
+            # Raise the original exception when entry cannot be a path to an
+            # app config class.
+            if not mod_path:
+                raise
+
+        else:
+            try:
+                # If this works, the app module specifies an app config class.
+                entry = module.default_app_config
+            except AttributeError:
+                # Otherwise, it simply uses the default app config class.
+                return cls(entry, module)
+            else:
+                mod_path, _, cls_name = entry.rpartition('.')
+
+        # If we're reaching this point, we must load the app config class
+        # located at <mod_path>.<cls_name>.
+
+        # Avoid django.utils.module_loading.import_by_path because it
+        # masks errors -- it reraises ImportError as ImproperlyConfigured.
+        mod = import_module(mod_path)
+        try:
+            cls = getattr(mod, cls_name)
+        except AttributeError:
+            # Emulate the error that "from <mod_path> import <cls_name>"
+            # would raise when <mod_path> exists but not <cls_name>, with
+            # more context (Python just says "cannot import name ...").
+            raise ImportError(
+                "cannot import name '%s' from '%s'" % (cls_name, mod_path))
+
+        # 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(
+                "'%s' 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(
+                "'%s' must supply a name attribute." % entry)
+
+        # Ensure app_name points to a valid module.
+        app_module = import_module(app_name)
+
+        # Entry is a path to an app config class.
+        return cls(app_name, app_module)
+
+
+    def get_model(self, model_name):
+        """
+        Returns the model with the given case-insensitive model_name.
+
+        Raises LookupError if no model exists with this name.
+        """
+        if self.models is None:
+            raise LookupError(
+                "App '%s' doesn't have any models." % self.label)
+        try:
+            return self.models[model_name.lower()]
+        except KeyError:
+            raise LookupError(
+                "App '%s' doesn't have a '%s' model." % (self.label, model_name))
+
+    def get_models(self, include_auto_created=False,
+                   include_deferred=False, include_swapped=False):
+        """
+        Returns an iterable of models.
+
+        By default, the following models aren't included:
+
+        - auto-created models for many-to-many relations without
+          an explicit intermediate table,
+        - models created to satisfy deferred attribute queries,
+        - models that have been swapped out.
+
+        Set the corresponding keyword argument to True to include such models.
+        Keyword arguments aren't documented; they're a private API.
+        """
+        for model in self.models.values():
+            if model._deferred and not include_deferred:
+                continue
+            if model._meta.auto_created and not include_auto_created:
+                continue
+            if model._meta.swapped and not include_swapped:
+                continue
+            yield model
+
+    def import_models(self, all_models):
+        # Dictionary of models for this app, primarily maintained in the
+        # 'all_models' attribute of the Apps this AppConfig is attached to.
+        # Injected as a parameter because it gets populated when models are
+        # imported, which might happen before populate() imports models.
+        self.models = all_models
+
+        if module_has_submodule(self.module, MODELS_MODULE_NAME):
+            models_module_name = '%s.%s' % (self.name, MODELS_MODULE_NAME)
+            self.models_module = import_module(models_module_name)
+
+    def ready(self):
+        """
+        Override this method in subclasses to run code when Django starts.
+        """