Add Event.set_defaults

src/pretix/api/views/event.py

@@ -133,6 +133,7 @@ class EventViewSet(viewsets.ModelViewSet):
 
     def perform_create(self, serializer):
         serializer.save(organizer=self.request.organizer)
+        serializer.instance.set_defaults()
         serializer.instance.log_action(
             'pretix.event.added',
             user=self.request.user,

src/pretix/base/models/event.py

@@ -363,6 +363,12 @@ class Event(EventMixin, LoggedModel):
     def __str__(self):
         return str(self.name)
 
+    def set_defaults(self):
+        """
+        This will be called after event creation, but only if the event was not created by copying an existing one.
+        This way, we can use this to introduce new default settings to pretix that do not affect existing events.
+        """
+
     @property
     def social_image(self):
         from pretix.multidomain.urlreverse import build_absolute_uri

src/pretix/control/views/main.py

@@ -267,17 +267,19 @@ class EventWizard(SafeSessionWizardView):
                 event.copy_data_from(from_event)
             elif self.clone_from:
                 event.copy_data_from(self.clone_from)
-            elif event.has_subevents:
-                event.checkin_lists.create(
-                    name=str(se),
-                    all_products=True,
-                    subevent=se
-                )
             else:
-                event.checkin_lists.create(
-                    name=_('Default'),
-                    all_products=True
-                )
+                if event.has_subevents:
+                    event.checkin_lists.create(
+                        name=str(se),
+                        all_products=True,
+                        subevent=se
+                    )
+                else:
+                    self.checkin_lists.create(
+                        name=_('Default'),
+                        all_products=True
+                    )
+                event.set_defaults()
 
             if basics_data['tax_rate']:
                 if not event.settings.tax_rate_default or event.settings.tax_rate_default.rate != basics_data['tax_rate']: