Commit b55282b9 authored by Aymeric Augustin's avatar Aymeric Augustin
Browse files

Moved list of models inside AppConfig instances. 

This commit is a refactoring with no change of functionality, according
to the following invariants:

- An app_label that was in app_configs and app_models stays in
  app_config and has its 'installed' attribute set to True.

- An app_label that was in app_models but not in app_configs is added to
  app_configs and has its 'installed' attribute set to True.

As a consequence, all the code that iterated on app_configs is modified
to check for the 'installed' attribute. Code that iterated on app_models
is rewritten in terms of app_configs.

Many tests that stored and restored the state of the app cache were
updated.

In the long term, we should reconsider the usefulness of allowing
importing models from non-installed applications. This doesn't sound
particularly useful, can be a trap in some circumstances, and causes
significant complexity in sensitive areas of Django.
parent 2c9e84af

django/apps/base.py

+15 −1
Original line number Diff line number Diff line 
from collections import OrderedDict





class AppConfig(object):

    """

    Class representing a Django application and its configuration.

    """



    def __init__(self, label, models_module):

    def __init__(self, label, models_module=None, installed=True):

        # Last component of the Python path to the application eg. 'admin'.

        self.label = label



        # Module containing models eg. <module 'django.contrib.admin.models'

        # from 'django/contrib/admin/models.pyc'>.

        self.models_module = models_module



        # Mapping of lower case model names to model classes.

        self.models = OrderedDict()



        # Whether the app is in INSTALLED_APPS or was automatically created

        # when one of its models was imported.

        self.installed = installed



    def __repr__(self):

        return '<AppConfig: %s>' % self.label

django/apps/cache.py

+33 −23
Original line number Diff line number Diff line
@@ -31,10 +31,6 @@ def _initialize(): 
        # Mapping of labels to AppConfig instances for installed apps.

        app_configs=OrderedDict(),



        # Mapping of app_labels to a dictionary of model names to model code.

        # May contain apps that are not installed.

        app_models=OrderedDict(),



        # Pending lookups for lazy relations

        pending_lookups={},
@@ -138,9 +134,15 @@ class BaseAppCache(object): 


        self.nesting_level -= 1

        label = self._label_for(models_module)

        if label not in self.app_configs:

        try:

            app_config = self.app_configs[label]

        except KeyError:

            self.app_configs[label] = AppConfig(

                label=label, models_module=models_module)

        else:

            if not app_config.installed:

                app_config.models_module = models_module

                app_config.installed = True

        return models_module



    def app_cache_ready(self):
@@ -161,7 +163,7 @@ class BaseAppCache(object): 
        # app_configs is an OrderedDict, which ensures that the returned list

        # is always in the same order (with new apps added at the end). This

        # avoids unstable ordering on the admin app list page, for example.

        apps = self.app_configs.items()

        apps = [app for app in self.app_configs.items() if app[1].installed]

        if self.available_apps is not None:

            apps = [app for app in apps if app[0] in self.available_apps]

        return [app[1].models_module for app in apps]
@@ -258,20 +260,20 @@ class BaseAppCache(object): 
        self._populate()

        if app_mod:

            app_label = self._label_for(app_mod)

            if app_label in self.app_configs:

                app_list = [self.app_models.get(app_label, OrderedDict())]

            else:

            try:

                app_config = self.app_configs[app_label]

            except KeyError:

                app_list = []

            else:

            if only_installed:

                app_list = [self.app_models.get(app_label, OrderedDict())

                            for app_label in self.app_configs]

                app_list = [app_config] if app_config.installed else []

        else:

                app_list = six.itervalues(self.app_models)

            app_list = six.itervalues(self.app_configs)

            if only_installed:

                app_list = (app for app in app_list if app.installed)

        model_list = []

        for app in app_list:

            model_list.extend(

                model for model in app.values()

                model for model in app.models.values()

                if ((not model._deferred or include_deferred) and

                    (not model._meta.auto_created or include_auto_created) and

                    (not model._meta.swapped or include_swapped))
@@ -296,13 +298,15 @@ class BaseAppCache(object): 
            only_installed = False

        if seed_cache:

            self._populate()

        if only_installed and app_label not in self.app_configs:

        if only_installed:

            app_config = self.app_configs.get(app_label)

            if app_config is not None and not app_config.installed:

                return None

        if (self.available_apps is not None and only_installed

            if (self.available_apps is not None

                    and app_label not in self.available_apps):

                raise UnavailableApp("App with label %s isn't available." % app_label)

        try:

            return self.app_models[app_label][model_name.lower()]

            return self.app_configs[app_label].models[model_name.lower()]

        except KeyError:

            return None
@@ -310,11 +314,17 @@ class BaseAppCache(object): 
        """

        Register a set of models as belonging to an app.

        """

        if models:

            try:

                app_config = self.app_configs[app_label]

            except KeyError:

                app_config = AppConfig(

                    label=app_label, installed=False)

                self.app_configs[app_label] = app_config

        for model in models:

            # Store as 'name: model' pair in a dictionary

            # in the app_models dictionary

            # Add the model to the app_config's models dictionary.

            model_name = model._meta.model_name

            model_dict = self.app_models.setdefault(app_label, OrderedDict())

            model_dict = app_config.models

            if model_name in model_dict:

                # The same model may be imported via different paths (e.g.

                # appname.models and project.appname.models). We use the source

tests/app_loading/tests.py

+6 −6
Original line number Diff line number Diff line 
from __future__ import unicode_literals



import copy

import os

import sys

from unittest import TestCase
@@ -17,14 +16,15 @@ class EggLoadingTest(TestCase): 
        self.old_path = sys.path[:]

        self.egg_dir = '%s/eggs' % os.path.dirname(upath(__file__))



        # This test adds dummy applications to the app cache. These

        # need to be removed in order to prevent bad interactions

        # with the flush operation in other tests.

        self.old_app_models = copy.deepcopy(app_cache.app_models)

        # The models need to be removed after the test in order to prevent bad

        # interactions with the flush operation in other tests.

        self._old_models = app_cache.app_configs['app_loading'].models.copy()



    def tearDown(self):

        app_cache.app_configs['app_loading'].models = self._old_models

        app_cache._get_models_cache = {}



        sys.path = self.old_path

        app_cache.app_models = self.old_app_models



    def test_egg1(self):

        """Models module can be loaded from an app in an egg"""

tests/invalid_models/tests.py

+4 −6
Original line number Diff line number Diff line 
import copy

import sys

import unittest
@@ -19,13 +18,12 @@ class InvalidModelTestCase(unittest.TestCase): 
        self.stdout = StringIO()

        sys.stdout = self.stdout



        # This test adds dummy applications to the app cache. These

        # need to be removed in order to prevent bad interactions

        # with the flush operation in other tests.

        self.old_app_models = copy.deepcopy(app_cache.app_models)

        # The models need to be removed after the test in order to prevent bad

        # interactions with the flush operation in other tests.

        self._old_models = app_cache.app_configs['invalid_models'].models.copy()



    def tearDown(self):

        app_cache.app_models = self.old_app_models

        app_cache.app_configs['invalid_models'].models = self._old_models

        app_cache._get_models_cache = {}

        sys.stdout = self.old_stdout

tests/managers_regress/tests.py

+18 −19
Original line number Diff line number Diff line 
from __future__ import unicode_literals

import copy



from django.apps import app_cache

from django.db import models
@@ -110,12 +109,11 @@ class ManagersRegressionTests(TestCase): 


    @override_settings(TEST_SWAPPABLE_MODEL='managers_regress.Parent')

    def test_swappable_manager(self):

        try:

            # This test adds dummy models to the app cache. These

            # need to be removed in order to prevent bad interactions

            # with the flush operation in other tests.

            old_app_models = copy.deepcopy(app_cache.app_models)

        # The models need to be removed after the test in order to prevent bad

        # interactions with the flush operation in other tests.

        _old_models = app_cache.app_configs['managers_regress'].models.copy()



        try:

            class SwappableModel(models.Model):

                class Meta:

                    swappable = 'TEST_SWAPPABLE_MODEL'
@@ -129,16 +127,16 @@ class ManagersRegressionTests(TestCase): 
                self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")



        finally:

            app_cache.app_models = old_app_models

            app_cache.app_configs['managers_regress'].models = _old_models

            app_cache._get_models_cache = {}



    @override_settings(TEST_SWAPPABLE_MODEL='managers_regress.Parent')

    def test_custom_swappable_manager(self):

        try:

            # This test adds dummy models to the app cache. These

            # need to be removed in order to prevent bad interactions

            # with the flush operation in other tests.

            old_app_models = copy.deepcopy(app_cache.app_models)

        # The models need to be removed after the test in order to prevent bad

        # interactions with the flush operation in other tests.

        _old_models = app_cache.app_configs['managers_regress'].models.copy()



        try:

            class SwappableModel(models.Model):



                stuff = models.Manager()
@@ -156,16 +154,16 @@ class ManagersRegressionTests(TestCase): 
                self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")



        finally:

            app_cache.app_models = old_app_models

            app_cache.app_configs['managers_regress'].models = _old_models

            app_cache._get_models_cache = {}



    @override_settings(TEST_SWAPPABLE_MODEL='managers_regress.Parent')

    def test_explicit_swappable_manager(self):

        try:

            # This test adds dummy models to the app cache. These

            # need to be removed in order to prevent bad interactions

            # with the flush operation in other tests.

            old_app_models = copy.deepcopy(app_cache.app_models)

        # The models need to be removed after the test in order to prevent bad

        # interactions with the flush operation in other tests.

        _old_models = app_cache.app_configs['managers_regress'].models.copy()



        try:

            class SwappableModel(models.Model):



                objects = models.Manager()
@@ -183,7 +181,8 @@ class ManagersRegressionTests(TestCase): 
                self.assertEqual(str(e), "Manager isn't available; SwappableModel has been swapped for 'managers_regress.Parent'")



        finally:

            app_cache.app_models = old_app_models

            app_cache.app_configs['managers_regress'].models = _old_models

            app_cache._get_models_cache = {}



    def test_regress_3871(self):

        related = RelatedModel.objects.create()