--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/parts/django/tests/modeltests/m2m_through/tests.py Sat Jan 08 11:20:57 2011 +0530
@@ -0,0 +1,343 @@
+from datetime import datetime
+from operator import attrgetter
+
+from django.test import TestCase
+
+from models import Person, Group, Membership, CustomMembership, \
+ TestNoDefaultsOrNulls, PersonSelfRefM2M, Friendship
+
+
+class M2mThroughTests(TestCase):
+ def setUp(self):
+ self.bob = Person.objects.create(name='Bob')
+ self.jim = Person.objects.create(name='Jim')
+ self.jane = Person.objects.create(name='Jane')
+ self.rock = Group.objects.create(name='Rock')
+ self.roll = Group.objects.create(name='Roll')
+
+ def test_m2m_through(self):
+ # We start out by making sure that the Group 'rock' has no members.
+ self.assertQuerysetEqual(
+ self.rock.members.all(),
+ []
+ )
+ # To make Jim a member of Group Rock, simply create a Membership object.
+ m1 = Membership.objects.create(person=self.jim, group=self.rock)
+ # We can do the same for Jane and Rock.
+ m2 = Membership.objects.create(person=self.jane, group=self.rock)
+ # Let's check to make sure that it worked. Jane and Jim should be members of Rock.
+ self.assertQuerysetEqual(
+ self.rock.members.all(), [
+ 'Jane',
+ 'Jim'
+ ],
+ attrgetter("name")
+ )
+ # Now we can add a bunch more Membership objects to test with.
+ m3 = Membership.objects.create(person=self.bob, group=self.roll)
+ m4 = Membership.objects.create(person=self.jim, group=self.roll)
+ m5 = Membership.objects.create(person=self.jane, group=self.roll)
+ # We can get Jim's Group membership as with any ForeignKey.
+ self.assertQuerysetEqual(
+ self.jim.group_set.all(), [
+ 'Rock',
+ 'Roll'
+ ],
+ attrgetter("name")
+ )
+ # Querying the intermediary model works like normal.
+ self.assertEqual(
+ repr(Membership.objects.get(person=self.jane, group=self.rock)),
+ '<Membership: Jane is a member of Rock>'
+ )
+ # It's not only get that works. Filter works like normal as well.
+ self.assertQuerysetEqual(
+ Membership.objects.filter(person=self.jim), [
+ '<Membership: Jim is a member of Rock>',
+ '<Membership: Jim is a member of Roll>'
+ ]
+ )
+ self.rock.members.clear()
+ # Now there will be no members of Rock.
+ self.assertQuerysetEqual(
+ self.rock.members.all(),
+ []
+ )
+
+
+
+ def test_forward_descriptors(self):
+ # Due to complications with adding via an intermediary model,
+ # the add method is not provided.
+ self.assertRaises(AttributeError, lambda: self.rock.members.add(self.bob))
+ # Create is also disabled as it suffers from the same problems as add.
+ self.assertRaises(AttributeError, lambda: self.rock.members.create(name='Anne'))
+ # Remove has similar complications, and is not provided either.
+ self.assertRaises(AttributeError, lambda: self.rock.members.remove(self.jim))
+
+ m1 = Membership.objects.create(person=self.jim, group=self.rock)
+ m2 = Membership.objects.create(person=self.jane, group=self.rock)
+
+ # Here we back up the list of all members of Rock.
+ backup = list(self.rock.members.all())
+ # ...and we verify that it has worked.
+ self.assertEqual(
+ [p.name for p in backup],
+ ['Jane', 'Jim']
+ )
+ # The clear function should still work.
+ self.rock.members.clear()
+ # Now there will be no members of Rock.
+ self.assertQuerysetEqual(
+ self.rock.members.all(),
+ []
+ )
+
+ # Assignment should not work with models specifying a through model for many of
+ # the same reasons as adding.
+ self.assertRaises(AttributeError, setattr, self.rock, "members", backup)
+ # Let's re-save those instances that we've cleared.
+ m1.save()
+ m2.save()
+ # Verifying that those instances were re-saved successfully.
+ self.assertQuerysetEqual(
+ self.rock.members.all(),[
+ 'Jane',
+ 'Jim'
+ ],
+ attrgetter("name")
+ )
+
+ def test_reverse_descriptors(self):
+ # Due to complications with adding via an intermediary model,
+ # the add method is not provided.
+ self.assertRaises(AttributeError, lambda: self.bob.group_set.add(self.rock))
+ # Create is also disabled as it suffers from the same problems as add.
+ self.assertRaises(AttributeError, lambda: self.bob.group_set.create(name="funk"))
+ # Remove has similar complications, and is not provided either.
+ self.assertRaises(AttributeError, lambda: self.jim.group_set.remove(self.rock))
+
+ m1 = Membership.objects.create(person=self.jim, group=self.rock)
+ m2 = Membership.objects.create(person=self.jim, group=self.roll)
+
+ # Here we back up the list of all of Jim's groups.
+ backup = list(self.jim.group_set.all())
+ self.assertEqual(
+ [g.name for g in backup],
+ ['Rock', 'Roll']
+ )
+ # The clear function should still work.
+ self.jim.group_set.clear()
+ # Now Jim will be in no groups.
+ self.assertQuerysetEqual(
+ self.jim.group_set.all(),
+ []
+ )
+ # Assignment should not work with models specifying a through model for many of
+ # the same reasons as adding.
+ self.assertRaises(AttributeError, setattr, self.jim, "group_set", backup)
+ # Let's re-save those instances that we've cleared.
+
+ m1.save()
+ m2.save()
+ # Verifying that those instances were re-saved successfully.
+ self.assertQuerysetEqual(
+ self.jim.group_set.all(),[
+ 'Rock',
+ 'Roll'
+ ],
+ attrgetter("name")
+ )
+
+ def test_custom_tests(self):
+ # Let's see if we can query through our second relationship.
+ self.assertQuerysetEqual(
+ self.rock.custom_members.all(),
+ []
+ )
+ # We can query in the opposite direction as well.
+ self.assertQuerysetEqual(
+ self.bob.custom.all(),
+ []
+ )
+
+ cm1 = CustomMembership.objects.create(person=self.bob, group=self.rock)
+ cm2 = CustomMembership.objects.create(person=self.jim, group=self.rock)
+
+ # If we get the number of people in Rock, it should be both Bob and Jim.
+ self.assertQuerysetEqual(
+ self.rock.custom_members.all(),[
+ 'Bob',
+ 'Jim'
+ ],
+ attrgetter("name")
+ )
+ # Bob should only be in one custom group.
+ self.assertQuerysetEqual(
+ self.bob.custom.all(),[
+ 'Rock'
+ ],
+ attrgetter("name")
+ )
+ # Let's make sure our new descriptors don't conflict with the FK related_name.
+ self.assertQuerysetEqual(
+ self.bob.custom_person_related_name.all(),[
+ '<CustomMembership: Bob is a member of Rock>'
+ ]
+ )
+
+ def test_self_referential_tests(self):
+ # Let's first create a person who has no friends.
+ tony = PersonSelfRefM2M.objects.create(name="Tony")
+ self.assertQuerysetEqual(
+ tony.friends.all(),
+ []
+ )
+
+ chris = PersonSelfRefM2M.objects.create(name="Chris")
+ f = Friendship.objects.create(first=tony, second=chris, date_friended=datetime.now())
+
+ # Tony should now show that Chris is his friend.
+ self.assertQuerysetEqual(
+ tony.friends.all(),[
+ 'Chris'
+ ],
+ attrgetter("name")
+ )
+ # But we haven't established that Chris is Tony's Friend.
+ self.assertQuerysetEqual(
+ chris.friends.all(),
+ []
+ )
+ f2 = Friendship.objects.create(first=chris, second=tony, date_friended=datetime.now())
+
+ # Having added Chris as a friend, let's make sure that his friend set reflects
+ # that addition.
+ self.assertQuerysetEqual(
+ chris.friends.all(),[
+ 'Tony'
+ ],
+ attrgetter("name")
+ )
+
+ # Chris gets mad and wants to get rid of all of his friends.
+ chris.friends.clear()
+ # Now he should not have any more friends.
+ self.assertQuerysetEqual(
+ chris.friends.all(),
+ []
+ )
+ # Since this isn't a symmetrical relation, Tony's friend link still exists.
+ self.assertQuerysetEqual(
+ tony.friends.all(),[
+ 'Chris'
+ ],
+ attrgetter("name")
+ )
+
+ def test_query_tests(self):
+ m1 = Membership.objects.create(person=self.jim, group=self.rock)
+ m2 = Membership.objects.create(person=self.jane, group=self.rock)
+ m3 = Membership.objects.create(person=self.bob, group=self.roll)
+ m4 = Membership.objects.create(person=self.jim, group=self.roll)
+ m5 = Membership.objects.create(person=self.jane, group=self.roll)
+
+ m2.invite_reason = "She was just awesome."
+ m2.date_joined = datetime(2006, 1, 1)
+ m2.save()
+ m3.date_joined = datetime(2004, 1, 1)
+ m3.save()
+ m5.date_joined = datetime(2004, 1, 1)
+ m5.save()
+
+ # We can query for the related model by using its attribute name (members, in
+ # this case).
+ self.assertQuerysetEqual(
+ Group.objects.filter(members__name='Bob'),[
+ 'Roll'
+ ],
+ attrgetter("name")
+ )
+
+ # To query through the intermediary model, we specify its model name.
+ # In this case, membership.
+ self.assertQuerysetEqual(
+ Group.objects.filter(membership__invite_reason="She was just awesome."),[
+ 'Rock'
+ ],
+ attrgetter("name")
+ )
+
+ # If we want to query in the reverse direction by the related model, use its
+ # model name (group, in this case).
+ self.assertQuerysetEqual(
+ Person.objects.filter(group__name="Rock"),[
+ 'Jane',
+ 'Jim'
+ ],
+ attrgetter("name")
+ )
+
+ cm1 = CustomMembership.objects.create(person=self.bob, group=self.rock)
+ cm2 = CustomMembership.objects.create(person=self.jim, group=self.rock)
+ # If the m2m field has specified a related_name, using that will work.
+ self.assertQuerysetEqual(
+ Person.objects.filter(custom__name="Rock"),[
+ 'Bob',
+ 'Jim'
+ ],
+ attrgetter("name")
+ )
+
+ # To query through the intermediary model in the reverse direction, we again
+ # specify its model name (membership, in this case).
+ self.assertQuerysetEqual(
+ Person.objects.filter(membership__invite_reason="She was just awesome."),[
+ 'Jane'
+ ],
+ attrgetter("name")
+ )
+
+ # Let's see all of the groups that Jane joined after 1 Jan 2005:
+ self.assertQuerysetEqual(
+ Group.objects.filter(membership__date_joined__gt=datetime(2005, 1, 1), membership__person=self.jane),[
+ 'Rock'
+ ],
+ attrgetter("name")
+ )
+
+ # Queries also work in the reverse direction: Now let's see all of the people
+ # that have joined Rock since 1 Jan 2005:
+ self.assertQuerysetEqual(
+ Person.objects.filter(membership__date_joined__gt=datetime(2005, 1, 1), membership__group=self.rock),[
+ 'Jane',
+ 'Jim'
+ ],
+ attrgetter("name")
+ )
+
+ # Conceivably, queries through membership could return correct, but non-unique
+ # querysets. To demonstrate this, we query for all people who have joined a
+ # group after 2004:
+ self.assertQuerysetEqual(
+ Person.objects.filter(membership__date_joined__gt=datetime(2004, 1, 1)),[
+ 'Jane',
+ 'Jim',
+ 'Jim'
+ ],
+ attrgetter("name")
+ )
+
+ # Jim showed up twice, because he joined two groups ('Rock', and 'Roll'):
+ self.assertEqual(
+ [(m.person.name, m.group.name) for m in Membership.objects.filter(date_joined__gt=datetime(2004, 1, 1))],
+ [(u'Jane', u'Rock'), (u'Jim', u'Rock'), (u'Jim', u'Roll')]
+ )
+ # QuerySet's distinct() method can correct this problem.
+ self.assertQuerysetEqual(
+ Person.objects.filter(membership__date_joined__gt=datetime(2004, 1, 1)).distinct(),[
+ 'Jane',
+ 'Jim'
+ ],
+ attrgetter("name")
+ )