Introduce `ContentType.objects.get_for_models(*models)` and use it in the the... (f04af708) · Commits · Dom Sekotill / django

django/contrib/auth/management/init.py

+2 −2

Original line number	Diff line number	Diff line
		@@ -31,8 +31,8 @@ def create_permissions(app, created_models, verbosity, **kwargs):
		searched_perms = list()
		# The codenames and ctypes that should exist.
		ctypes = set()
		for klass in app_models:
		ctype = ContentType.objects.get_for_model(klass)
		ctypes_for_models = ContentType.objects.get_for_models(*app_models)
		for klass, ctype in ctypes_for_models.iteritems():
		ctypes.add(ctype)
		for perm in _get_all_permissions(klass._meta):
		searched_perms.append((ctype, perm))

django/contrib/contenttypes/models.py

+55 −6

Original line number	Diff line number	Diff line
		@@ -15,19 +15,26 @@ class ContentTypeManager(models.Manager):
		ct = self.get(app_label=app_label, model=model)
		return ct

		def _get_opts(self, model):
		opts = model._meta
		while opts.proxy:
		model = opts.proxy_for_model
		opts = model._meta
		return opts

		def _get_from_cache(self, opts):
		key = (opts.app_label, opts.object_name.lower())
		return self.__class__._cache[self.db][key]

		def get_for_model(self, model):
		"""
		Returns the ContentType object for a given model, creating the
		ContentType if necessary. Lookups are cached so that subsequent lookups
		for the same model don't hit the database.
		"""
		opts = model._meta
		while opts.proxy:
		model = opts.proxy_for_model
		opts = model._meta
		key = (opts.app_label, opts.object_name.lower())
		opts = self._get_opts(model)
		try:
		ct = self.__class__._cache[self.db][key]
		ct = self._get_from_cache(opts)
		except KeyError:
		# Load or create the ContentType entry. The smart_unicode() is
		# needed around opts.verbose_name_raw because name_raw might be a
		@@ -41,6 +48,48 @@ class ContentTypeManager(models.Manager):

		return ct

		def get_for_models(self, *models):
		"""
		Given *models, returns a dictionary mapping {model: content_type}.
		"""
		# Final results
		results = {}
		# models that aren't already in the cache
		needed_app_labels = set()
		needed_models = set()
		needed_opts = set()
		for model in models:
		opts = self._get_opts(model)
		try:
		ct = self._get_from_cache(opts)
		except KeyError:
		needed_app_labels.add(opts.app_label)
		needed_models.add(opts.object_name.lower())
		needed_opts.add(opts)
		else:
		results[model] = ct
		if needed_opts:
		cts = self.filter(
		app_label__in=needed_app_labels,
		model__in=needed_models
		)
		for ct in cts:
		model = ct.model_class()
		if model._meta in needed_opts:
		results[model] = ct
		needed_opts.remove(model._meta)
		self._add_to_cache(self.db, ct)
		for opts in needed_opts:
		# These weren't in the cache, or the DB, create them.
		ct = self.create(
		app_label=opts.app_label,
		model=opts.object_name.lower(),
		name=smart_unicode(opts.verbose_name_raw),
		)
		self._add_to_cache(self.db, ct)
		results[ct.model_class()] = ct
		return results

		def get_for_id(self, id):
		"""
		Lookup a ContentType by ID. Uses the same shared cache as get_for_model

django/contrib/contenttypes/tests.py

+30 −0

Original line number	Diff line number	Diff line
		@@ -63,6 +63,36 @@ class ContentTypesTests(TestCase):
		with self.assertNumQueries(1):
		ContentType.objects.get_for_model(ContentType)

		def test_get_for_models_empty_cache(self):
		# Empty cache.
		with self.assertNumQueries(1):
		cts = ContentType.objects.get_for_models(ContentType, FooWithUrl)
		self.assertEqual(cts, {
		ContentType: ContentType.objects.get_for_model(ContentType),
		FooWithUrl: ContentType.objects.get_for_model(FooWithUrl),
		})

		def test_get_for_models_partial_cache(self):
		# Partial cache
		ContentType.objects.get_for_model(ContentType)
		with self.assertNumQueries(1):
		cts = ContentType.objects.get_for_models(ContentType, FooWithUrl)
		self.assertEqual(cts, {
		ContentType: ContentType.objects.get_for_model(ContentType),
		FooWithUrl: ContentType.objects.get_for_model(FooWithUrl),
		})

		def test_get_for_models_full_cache(self):
		# Full cache
		ContentType.objects.get_for_model(ContentType)
		ContentType.objects.get_for_model(FooWithUrl)
		with self.assertNumQueries(0):
		cts = ContentType.objects.get_for_models(ContentType, FooWithUrl)
		self.assertEqual(cts, {
		ContentType: ContentType.objects.get_for_model(ContentType),
		FooWithUrl: ContentType.objects.get_for_model(FooWithUrl),
		})

		def test_shortcut_view(self):
		"""
		Check that the shortcut view (used for the admin "view on site"

docs/ref/contrib/contenttypes.txt

+9 −2

Original line number	Diff line number	Diff line
		@@ -193,6 +193,13 @@ The ``ContentTypeManager``
		:class:`~django.contrib.contenttypes.models.ContentType` instance
		representing that model.

		.. method:: get_for_models(*models)

		Takes a variadic number of model classes, and returns a dictionary
		mapping the model classes to the
		:class:`~django.contrib.contenttypes.models.ContentType` instances
		representing them.

		.. method:: get_by_natural_key(app_label, model)

		Returns the :class:`~django.contrib.contenttypes.models.ContentType`