Move settings check for carry_data_over to save method

Makes it possible to use the function in other contexts

aleksis/apps/alsijil/models.py

@@ -111,9 +111,6 @@ class LessonDocumentation(ExtensibleModel):
 
         Can be deactivated using site preference ``alsijil__carry_over``.
         """
-        if get_site_preferences()["alsijil__carry_over"] and (
-            self.topic or self.homework or self.group_note
-        ):
         try:
             second_period = LessonPeriod.objects.get(
                 lesson=self.lesson_period.lesson,
@@ -122,8 +119,7 @@ class LessonDocumentation(ExtensibleModel):
             )
             lesson_documentation = second_period.get_or_create_lesson_documentation(
                 CalendarWeek(
-                        week=self.week,
-                        year=self.lesson_period.lesson.get_year(self.week),
+                    week=self.week, year=self.lesson_period.lesson.get_year(self.week),
                 )
             )
 
@@ -148,6 +144,9 @@ class LessonDocumentation(ExtensibleModel):
             pass
 
     def save(self, *args, **kwargs):
+        if get_site_preferences()["alsijil__carry_over"] and (
+            self.topic or self.homework or self.group_note
+        ):
             self._carry_over_data()
         super().save(*args, **kwargs)