[bug 627781] Move object_id back into Watch and test for cascading deletes.

Also add missing migration (accidentally removed in previous commit).

apps/notifications/models.py

@@ -2,6 +2,7 @@ import hashlib
 
 from django.db import models
 from django.contrib.auth.models import User
+from django.contrib.contenttypes import generic
 from django.contrib.contenttypes.models import ContentType
 
 from sumo.models import ModelBase, LocaleField
@@ -58,6 +59,8 @@ class Watch(ModelBase):
 
     # Optional reference to a content type:
     content_type = models.ForeignKey(ContentType, null=True, blank=True)
+    object_id = models.PositiveIntegerField(db_index=True, null=True)
+    content_object = generic.GenericForeignKey('content_type', 'object_id')
 
     user = models.ForeignKey(User, null=True, blank=True)
 
@@ -81,3 +84,15 @@ class WatchFilter(ModelBase):
     # Either ints or hashes of enumerated strings. All we can't represent
     # easily with this schema is arbitrary (open-vocab) strings.
     value = models.IntegerField()
+
+
+class NotificationsMixin(models.Model):
+    """Mixin for notifications models that adds watches as a generic relation.
+
+    So we get cascading deletes for free, yay!
+
+    """
+    watches = generic.GenericRelation(Watch)
+
+    class Meta(object):
+        abstract = True

apps/notifications/tests/__init__.py

@@ -1,4 +1,9 @@
+from django.conf import settings
+from django.core.management import call_command
+from django.db.models import loading
+
 from notifications.models import Watch, WatchFilter
+from sumo.tests import TestCase
 from users.tests import user
 
 
@@ -21,3 +26,34 @@ def watch_filter(save=False, **kwargs):
     if save:
         f.save()
     return f
+
+
+class ModelsTestCase(TestCase):
+    """Does some pre-setup and post-teardown work to create tables for any
+    of your test models.
+
+    Simply subclass this and set self.apps to a tuple of *additional*
+    installed apps. These will be added *after* the ones in
+    settings.INSTALLED_APPS.
+
+    Based on http://stackoverflow.com/questions/502916#1827272
+
+    """
+    apps = []
+
+    def _pre_setup(self):
+        # Add the models to the db.
+        self._original_installed_apps = list(settings.INSTALLED_APPS)
+        for app in self.apps:
+            settings.INSTALLED_APPS.append(app)
+        loading.cache.loaded = False
+        call_command('syncdb', interactive=False, verbosity=0)
+        # Call the original method that does the fixtures etc.
+        super(ModelsTestCase, self)._pre_setup()
+
+    def _post_teardown(self):
+        # Call the original method.
+        super(ModelsTestCase, self)._post_teardown()
+        # Restore the settings.
+        settings.INSTALLED_APPS = self._original_installed_apps
+        loading.cache.loaded = False

apps/notifications/tests/models.py

@@ -0,0 +1,9 @@
+from django.db import models
+
+from notifications.models import NotificationsMixin
+
+
+# TODO: figure out why placing the mixin *after* models.Model fails
+# See also http://code.djangoproject.com/ticket/10249
+class MockModel(NotificationsMixin, models.Model):
+    pass

apps/notifications/tests/test_events.py

@@ -4,7 +4,8 @@ from django.contrib.contenttypes.models import ContentType
 
 from notifications.events import Event
 from notifications.models import Watch
-from notifications.tests import watch, watch_filter
+from notifications.tests import watch, watch_filter, ModelsTestCase
+from notifications.tests.models import MockModel
 from sumo.tests import TestCase
 from users.tests import user
 
@@ -140,3 +141,21 @@ class TestNotification(TestCase):
         FilteredContentTypeEvent.notify('hi@there.com', color=3, flavor=4)
         assert not FilteredContentTypeEvent.is_notifying('hi@there.com',
                                                          color=3)
+
+
+class TestCascadeDelete(ModelsTestCase):
+    """Cascading deletes on object_id + content_type."""
+    apps = ['notifications.tests']
+
+    def test_mock_model(self):
+        """Deleting an instance of MockModel should delete watches.
+
+        Create instance of MockModel from notifications.tests.models, then
+        delete it and watch the cascade go.
+
+        """
+        mock_m = MockModel.objects.create()
+        watch(event_type=TYPE, email='hi@there.com', content_object=mock_m,
+              save=True)
+        MockModel.objects.all().delete()
+        assert not Watch.objects.count(), 'Cascade delete failed.'

migrations/76-new-notifications.sql

@@ -0,0 +1,29 @@
+CREATE TABLE `notifications_watch` (
+  `id` integer NOT NULL AUTO_INCREMENT,
+  `event_type` varchar(30) binary NOT NULL,
+  `content_type_id` integer DEFAULT NULL,
+  `object_id` integer unsigned DEFAULT NULL,
+  `user_id` integer DEFAULT NULL,
+  `email` varchar(75) DEFAULT NULL,
+  `secret` varchar(10) DEFAULT NULL,
+  PRIMARY KEY (`id`),
+  KEY `notifications_watch_2be07fce` (`event_type`),
+  KEY `notifications_watch_e4470c6e` (`content_type_id`),
+  KEY `notifications_watch_829e37fd` (`object_id`),
+  KEY `notifications_watch_fbfc09f1` (`user_id`),
+  KEY `notifications_watch_3904588a` (`email`),
+  CONSTRAINT `content_type_id_refs_id_23da5933` FOREIGN KEY (`content_type_id`) REFERENCES `django_content_type` (`id`),
+  CONSTRAINT `user_id_refs_id_2dc6eef1` FOREIGN KEY (`user_id`) REFERENCES `auth_user` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;
+
+
+CREATE TABLE `notifications_watchfilter` (
+  `id` integer NOT NULL AUTO_INCREMENT,
+  `watch_id` integer NOT NULL,
+  `name` binary(20) NOT NULL,
+  `value` integer NOT NULL,
+  PRIMARY KEY (`id`),
+  KEY `notifications_watchfilter_6e1bd094` (`watch_id`),
+  KEY `notifications_watchfilter_52094d6e` (`name`),
+  CONSTRAINT `watch_id_refs_id_444d6e79` FOREIGN KEY (`watch_id`) REFERENCES `notifications_watch` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8;