agendas: factorize recurring event update code (#57305)

chrono/agendas/models.py

@@ -22,6 +22,7 @@ import itertools
 import math
 import sys
 import uuid
+from contextlib import contextmanager
 
 import requests
 import vobject
@@ -1409,6 +1410,23 @@ class Event(models.Model):
             self.slug = generate_slug(self, seen_slugs=seen_slugs, agenda=self.agenda)
         return super().save(*args, **kwargs)
 
+    @contextmanager
+    def update_recurrences(self, changed_data, cleaned_data, protected_fields, exclude_fields):
+        with transaction.atomic():
+            if any(field for field in changed_data if field in protected_fields):
+                self.recurrences.all().delete()
+            elif self.recurrence_days:
+                update_fields = {
+                    field: value for field, value in cleaned_data.items() if field not in exclude_fields
+                }
+                self.recurrences.update(**update_fields)
+            yield
+
+            if self.recurrence_end_date:
+                self.recurrences.filter(start_datetime__gt=self.recurrence_end_date).delete()
+                excluded_datetimes = [evt.datetime_slug for evt in self.recurrences.all()]
+                self.create_all_recurrences(excluded_datetimes)
+
     @property
     def base_slug(self):
         # label can be empty

chrono/manager/forms.py

@@ -24,7 +24,6 @@ from django import forms
 from django.conf import settings
 from django.contrib.auth.models import Group
 from django.core.exceptions import FieldDoesNotExist
-from django.db import transaction
 from django.forms import ValidationError
 from django.utils.encoding import force_text
 from django.utils.six import StringIO
@@ -280,25 +279,13 @@ class EventForm(NewEventForm):
             self.cleaned_data['recurrence_end_date'] = None
 
     def save(self, *args, **kwargs):
-        with transaction.atomic():
-            if any(field for field in self.changed_data if field in self.protected_fields):
-                self.instance.recurrences.all().delete()
-            elif self.instance.recurrence_days:
-                protected_fields = list(self.protected_fields) + ['recurrence_end_date', 'frequency']
-                update_fields = {
-                    field: value
-                    for field, value in self.cleaned_data.items()
-                    if field not in protected_fields
-                }
-                self.instance.recurrences.update(**update_fields)
-
+        with self.instance.update_recurrences(
+            self.changed_data,
+            self.cleaned_data,
+            self.protected_fields,
+            list(self.protected_fields) + ['recurrence_end_date', 'frequency'],
+        ):
             super().save(*args, **kwargs)
-            if self.instance.recurrence_end_date:
-                self.instance.recurrences.filter(
-                    start_datetime__gt=self.instance.recurrence_end_date
-                ).delete()
-                excluded_datetimes = [event.datetime_slug for event in self.instance.recurrences.all()]
-                self.instance.create_all_recurrences(excluded_datetimes)
         return self.instance