Fixed signals can not connect to OneToOneField (#572)

Author: 954-Ivory

django_celery_beat/apps.py

@@ -12,3 +12,7 @@ class BeatConfig(AppConfig):
     label = 'django_celery_beat'
     verbose_name = _('Periodic Tasks')
     default_auto_field = 'django.db.models.AutoField'
+
+    def ready(self):
+        from .signals import signals_connect
+        signals_connect()

django_celery_beat/models.py

@@ -619,23 +619,3 @@ def schedule(self):
             return self.solar.schedule
         if self.clocked:
             return self.clocked.schedule
-
-
-signals.pre_delete.connect(PeriodicTasks.changed, sender=PeriodicTask)
-signals.pre_save.connect(PeriodicTasks.changed, sender=PeriodicTask)
-signals.pre_delete.connect(
-    PeriodicTasks.update_changed, sender=IntervalSchedule)
-signals.post_save.connect(
-    PeriodicTasks.update_changed, sender=IntervalSchedule)
-signals.post_delete.connect(
-    PeriodicTasks.update_changed, sender=CrontabSchedule)
-signals.post_save.connect(
-    PeriodicTasks.update_changed, sender=CrontabSchedule)
-signals.post_delete.connect(
-    PeriodicTasks.update_changed, sender=SolarSchedule)
-signals.post_save.connect(
-    PeriodicTasks.update_changed, sender=SolarSchedule)
-signals.post_delete.connect(
-    PeriodicTasks.update_changed, sender=ClockedSchedule)
-signals.post_save.connect(
-    PeriodicTasks.update_changed, sender=ClockedSchedule)

django_celery_beat/signals.py

@@ -0,0 +1,41 @@
+def signals_connect():
+    from django.db.models import signals, OneToOneRel
+    from .models import ClockedSchedule, PeriodicTask, PeriodicTasks, IntervalSchedule, CrontabSchedule, SolarSchedule
+
+    def o2o_discover():
+        """
+        Description: Discover the `OneToOneField`, and connect their signals to `PeriodicTasks.changed`.
+
+        Issues: Signals can not connect to OneToOneField.
+                https://github.com/celery/django-celery-beat/issues/572
+
+        Note: The inheritance relationship introduces links between the child model and each of its
+              parents (via an automatically-created OneToOneField).
+              https://docs.djangoproject.com/en/stable/topics/db/models/#multi-table-inheritance
+        """
+        related_objects = PeriodicTask._meta.related_objects
+        for obj in related_objects:
+            if isinstance(obj, OneToOneRel):
+                sender_class = obj.related_model
+                signals.pre_delete.connect(PeriodicTasks.changed, sender=sender_class)
+                signals.pre_save.connect(PeriodicTasks.changed, sender=sender_class)
+
+    o2o_discover()
+    signals.pre_delete.connect(PeriodicTasks.changed, sender=PeriodicTask)
+    signals.pre_save.connect(PeriodicTasks.changed, sender=PeriodicTask)
+    signals.pre_delete.connect(
+        PeriodicTasks.update_changed, sender=IntervalSchedule)
+    signals.post_save.connect(
+        PeriodicTasks.update_changed, sender=IntervalSchedule)
+    signals.post_delete.connect(
+        PeriodicTasks.update_changed, sender=CrontabSchedule)
+    signals.post_save.connect(
+        PeriodicTasks.update_changed, sender=CrontabSchedule)
+    signals.post_delete.connect(
+        PeriodicTasks.update_changed, sender=SolarSchedule)
+    signals.post_save.connect(
+        PeriodicTasks.update_changed, sender=SolarSchedule)
+    signals.post_delete.connect(
+        PeriodicTasks.update_changed, sender=ClockedSchedule)
+    signals.post_save.connect(
+        PeriodicTasks.update_changed, sender=ClockedSchedule)