Move inheritance to resource events

* Use recent permission.remove_principal() method
* Use ACTIONS constants

kinto/views/buckets.py

@@ -1,4 +1,7 @@
 from cliquet import resource
+from cliquet.events import ResourceChanged, ACTIONS
+from pyramid.events import subscriber
+
 from kinto.views import NameGenerator
 
 
@@ -23,33 +26,39 @@ def get_parent_id(self, request):
         # Buckets are not isolated by user, unlike Cliquet resources.
         return ''
 
-    def delete(self):
-        result = super(Bucket, self).delete()
+
+@subscriber(ResourceChanged,
+            for_resources=('bucket',),
+            for_actions=(ACTIONS.DELETE,))
+def on_buckets_deleted(event):
+    """Some buckets were deleted, delete sub-resources.
+    """
+    storage = event.request.registry.storage
+
+    for change in event.impacted_records:
+        bucket = change['old']
+        parent_id = '/buckets/%s' % bucket['id']
 
         # Delete groups.
-        storage = self.model.storage
-        parent_id = '/buckets/%s' % self.record_id
         storage.delete_all(collection_id='group',
                            parent_id=parent_id,
                            with_deleted=False)
         storage.purge_deleted(collection_id='group',
                               parent_id=parent_id)
 
         # Delete collections.
-        deleted = storage.delete_all(collection_id='collection',
-                                     parent_id=parent_id,
-                                     with_deleted=False)
+        deleted_collections = storage.delete_all(collection_id='collection',
+                                                 parent_id=parent_id,
+                                                 with_deleted=False)
         storage.purge_deleted(collection_id='collection',
                               parent_id=parent_id)
 
         # Delete records.
-        id_field = self.model.id_field
-        for collection in deleted:
-            parent_id = '/buckets/%s/collections/%s' % (self.record_id,
-                                                        collection[id_field])
+        for collection in deleted_collections:
+            parent_id = '/buckets/%s/collections/%s' % (bucket['id'],
+                                                        collection['id'])
             storage.delete_all(collection_id='record',
                                parent_id=parent_id,
                                with_deleted=False)
-            storage.purge_deleted(collection_id='record', parent_id=parent_id)
-
-        return result
+            storage.purge_deleted(collection_id='record',
+                                  parent_id=parent_id)

kinto/views/collections.py

@@ -1,7 +1,9 @@
 import colander
 import jsonschema
 from cliquet import resource
+from cliquet.events import ResourceChanged, ACTIONS
 from jsonschema import exceptions as jsonschema_exceptions
+from pyramid.events import subscriber
 
 from kinto.views import NameGenerator
 
@@ -50,16 +52,21 @@ def get_parent_id(self, request):
         parent_id = '/buckets/%s' % bucket_id
         return parent_id
 
-    def delete(self):
-        result = super(Collection, self).delete()
 
-        # Delete records.
-        storage = self.model.storage
-        parent_id = '%s/collections/%s' % (self.model.parent_id,
-                                           self.record_id)
+@subscriber(ResourceChanged,
+            for_resources=('collection',),
+            for_actions=(ACTIONS.DELETE,))
+def on_collections_deleted(event):
+    """Some collections were deleted, delete records.
+    """
+    storage = event.request.registry.storage
+
+    for change in event.impacted_records:
+        collection = change['old']
+        parent_id = '/buckets/%s/collections/%s' % (event.payload['bucket_id'],
+                                                    collection['id'])
         storage.delete_all(collection_id='record',
                            parent_id=parent_id,
                            with_deleted=False)
-        storage.purge_deleted(collection_id='record', parent_id=parent_id)
-
-        return result
+        storage.purge_deleted(collection_id='record',
+                              parent_id=parent_id)

kinto/views/groups.py

@@ -1,6 +1,8 @@
 import colander
 
 from cliquet import resource
+from cliquet.events import ResourceChanged, ACTIONS
+from pyramid.events import subscriber
 
 from kinto.views import NameGenerator
 
@@ -26,49 +28,47 @@ def get_parent_id(self, request):
         parent_id = '/buckets/%s' % bucket_id
         return parent_id
 
-    def collection_delete(self):
-        filters = self._extract_filters()
-        groups, _ = self.model.get_records(filters=filters)
-        body = super(Group, self).collection_delete()
-        permission = self.request.registry.permission
-        for group in groups:
-            group_id = self.context.get_permission_object_id(
-                self.request, group[self.model.id_field])
-            # Remove the group's principal from all members of the group.
-            for member in group['members']:
-                permission.remove_user_principal(
-                    member,
-                    group_id)
-        return body
-
-    def delete(self):
-        group = self._get_record_or_404(self.record_id)
-        permission = self.request.registry.permission
-        body = super(Group, self).delete()
-        group_id = self.context.permission_object_id
-        for member in group['members']:
-            # Remove the group's principal from all members of the group.
-            permission.remove_user_principal(member, group_id)
-        return body
-
-    def process_record(self, new, old=None):
-        if old is None:
-            existing_record_members = set()
+
+@subscriber(ResourceChanged,
+            for_resources=('group',),
+            for_actions=(ACTIONS.DELETE,))
+def on_groups_deleted(event):
+    """Some groups were deleted, remove them from users principals.
+    """
+    permission_backend = event.request.registry.permission
+
+    for change in event.impacted_records:
+        group = change['old']
+        group_uri = '/buckets/{bucket_id}/groups/{id}'.format(id=group['id'],
+                                                              **event.payload)
+        permission_backend.remove_principal(group_uri)
+
+
+@subscriber(ResourceChanged,
+            for_resources=('group',),
+            for_actions=(ACTIONS.CREATE, ACTIONS.UPDATE))
+def on_groups_changed(event):
+    """Some groups were changed, update users principals.
+    """
+    permission_backend = event.request.registry.permission
+
+    for change in event.impacted_records:
+        if 'old' in change:
+            existing_record_members = set(change['old'].get('members', []))
         else:
-            existing_record_members = set(old.get('members', []))
-        new_record_members = set(new['members'])
+            existing_record_members = set()
+
+        group = change['new']
+        group_uri = '/buckets/{bucket_id}/groups/{id}'.format(id=group['id'],
+                                                              **event.payload)
+        new_record_members = set(group.get('members', []))
         new_members = new_record_members - existing_record_members
         removed_members = existing_record_members - new_record_members
 
-        group_principal = self.context.get_permission_object_id(
-            self.request, self.record_id)
-        permission = self.request.registry.permission
         for member in new_members:
             # Add the group to the member principal.
-            permission.add_user_principal(member, group_principal)
+            permission_backend.add_user_principal(member, group_uri)
 
         for member in removed_members:
             # Remove the group from the member principal.
-            permission.remove_user_principal(member, group_principal)
-
-        return new
+            permission_backend.remove_user_principal(member, group_uri)