def test_generic_related_objects(self):
"""
Check that get_generic_related_objects correctly populates the _assets
attribute of each element with a GenericRelation, in fewer queries than
simply iterating through and checking x.assets.all().
"""
articles = Article.objects.all()
assets_original = []
for article in articles:
assets_original.extend(list(article.assets.all()))
self.assertEquals(len(connection.queries), 22)
self.assertEquals(len(assets_original), 100)
reset_queries()
ContentType.objects.clear_cache()
get_generic_related_objects(articles, 'assets')
assets_efficient = []
for article in articles:
assets_efficient.extend(article._assets)
for asset in article._assets:
self.assertEquals(asset.object_id, article.id)
self.assertEquals(len(assets_efficient), 100)
self.assertEquals(assets_efficient, assets_original)
# one query to get contenttype, then one to get all assets
self.assertEquals(len(connection.queries), 2)
self.assertRaises(RelationNotFound, get_generic_related_objects,
articles, 'nonexistentrelationship')
def get_generic_related_objects(queryset, relation_name):
utils.get_generic_related_objects(queryset, relation_name)
