diff --git a/django/db/models/options.py b/django/db/models/options.py index 7daf756391..03470408e0 100644 --- a/django/db/models/options.py +++ b/django/db/models/options.py @@ -487,12 +487,6 @@ class Options(object): @cached_property def fields_map(self): - return self._get_fields_map() - - def _get_fields_map(self): - # Helper method to provide a way to access this without caching it. - # For example, admin checks run before the app cache is ready and we - # need to be able to lookup fields before we cache the final result. res = {} fields = self._get_fields(forward=False, include_hidden=True) for field in fields: @@ -537,26 +531,20 @@ class Options(object): return field except KeyError: - pass - - if m2m_in_kwargs: - # Previous API does not allow searching reverse fields. - raise FieldDoesNotExist('%s has no field named %r' % (self.object_name, field_name)) - - # If the app registry is not ready, reverse fields are probably - # unavailable, but try anyway. - if not self.apps.ready: - try: - # Don't cache results - return self._get_fields_map()[field_name] - except KeyError: + # If the app registry is not ready, reverse fields are + # unavailable, therefore we throw a FieldDoesNotExist exception. + if not self.apps.ready: raise FieldDoesNotExist( "%s has no field named %r. The app cache isn't ready yet, " - "so if this is an auto-created related field, it might not " + "so if this is an auto-created related field, it won't " "be available yet." % (self.object_name, field_name) ) try: + if m2m_in_kwargs: + # Previous API does not allow searching reverse fields. + raise FieldDoesNotExist('%s has no field named %r' % (self.object_name, field_name)) + # Retrieve field instance by name from cached or just-computed # field map. return self.fields_map[field_name] diff --git a/tests/model_meta/tests.py b/tests/model_meta/tests.py index bc7927c313..1a0c2de9f3 100644 --- a/tests/model_meta/tests.py +++ b/tests/model_meta/tests.py @@ -169,30 +169,24 @@ class GetFieldByNameTests(OptionsBaseTests): self.assertEqual(field_info[1:], (None, True, False)) self.assertIsInstance(field_info[0], GenericRelation) - def test_get_fields_when_apps_not_ready(self): + def test_get_fields_only_searches_forward_on_apps_not_ready(self): opts = Person._meta # If apps registry is not ready, get_field() searches over only # forward fields. opts.apps.ready = False - # Clear cached data. - opts.__dict__.pop('fields_map', None) try: # 'data_abstract' is a forward field, and therefore will be found self.assertTrue(opts.get_field('data_abstract')) msg = ( - "Person has no field named 'some_missing_field'. The app " + "Person has no field named 'relating_baseperson'. The app " "cache isn't ready yet, so if this is an auto-created related " - "field, it might not be available yet." + "field, it won't be available yet." ) + # 'data_abstract' is a reverse field, and will raise an exception with self.assertRaisesMessage(FieldDoesNotExist, msg): - opts.get_field('some_missing_field') - # Be sure it's not cached - self.assertNotIn('fields_map', opts.__dict__) + opts.get_field('relating_baseperson') finally: opts.apps.ready = True - # At this point searching a related field would cache fields_map - opts.get_field('relating_baseperson') - self.assertIn('fields_map', opts.__dict__) class RelationTreeTests(TestCase):