Add preferences for timetable change notifications

aleksis/apps/chronos/model_extensions.py

@@ -171,6 +171,9 @@ Person.add_permission(
 @receiver(timetable_data_changed)
 def send_notifications(sender: Revision, **kwargs):
     """Send notifications to users about the changes."""
+    if not get_site_preferences()["chronos__send_notifications"]:
+        return
+
     for change in sender.changes.values():
         if change.deleted:
             continue
@@ -360,11 +363,12 @@ def send_notifications(sender: Revision, **kwargs):
         )
 
         for recipient in recipients:
-            n = Notification(
-                recipient=recipient,
-                sender=_("Timetable"),
-                title=_("There are current changes to your timetable."),
-                description=description,
-                link=url,
-            )
-            n.save()
+            if recipient.preferences["chronos__send_notifications"]:
+                n = Notification(
+                    recipient=recipient,
+                    sender=_("Timetable"),
+                    title=_("There are current changes to your timetable."),
+                    description=description,
+                    link=url,
+                )
+                n.save()

aleksis/apps/chronos/preferences.py

@@ -78,3 +78,19 @@ class TimeForSendingNotifications(TimePreference):
     default = time(17, 00)
     verbose_name = _("Time for sending notifications for the next day")
     required = True
+
+
+@site_preferences_registry.register
+class SendNotifications(BooleanPreference):
+    section = chronos
+    name = "send_notifications"
+    default = True
+    verbose_name = _("Send notifications for current timetable changes")
+
+
+@person_preferences_registry.register
+class SendNotificationsPerson(BooleanPreference):
+    section = chronos
+    name = "send_notifications"
+    default = True
+    verbose_name = _("Send notifications for current timetable changes")