Replace complicated query with two queries and process Python-side

Cache member_groups

Make logic in is_organiser more explicit

Do explicit cache invalidation in test

invalidate cache in more places

fix

website/events/services.py

@@ -272,11 +272,13 @@ def is_organiser(member, event):
             return True
 
         if event:
-            return (
-                member.get_member_groups()
-                .filter(pk__in=event.organisers.values_list("pk"))
-                .exists()
-            )
+            member_groups = set(member.member_groups)
+
+            for organiser in event.organisers.all():
+                if organiser in member_groups:
+                    return True
+
+            return False
 
     return False
 

website/events/tests/test_services.py

@@ -185,6 +185,7 @@ def test_is_organiser(self):
         membership = MemberGroupMembership.objects.create(
             member=self.member, group=self.committee
         )
+        del self.member.member_groups
         self.assertTrue(services.is_organiser(self.member, self.event))
         self.assertFalse(services.is_organiser(self.member, None))
         self._toggle_event_change_perm(False)

website/members/models/member.py

@@ -215,5 +215,9 @@ def get_member_groups(self):
             active=True,
         )
 
+    @cached_property
+    def member_groups(self):
+        return self.get_member_groups()
+
     def get_absolute_url(self):
         return reverse("members:profile", args=[str(self.pk)])