Tillad ikke at slette aktiviteter med inviterede

members/admin/activity_admin.py

@@ -1,5 +1,6 @@
-from django.contrib import admin
+from django.contrib import admin, messages
 from django.conf import settings
+from django.core.exceptions import ValidationError
 from django.urls import reverse
 from django.utils.safestring import mark_safe
 from django.utils.html import escape, format_html
@@ -250,6 +251,21 @@ def formfield_for_foreignkey(self, db_field, request, **kwargs):
             kwargs["queryset"] = Address.get_user_addresses(request.user)
         return super().formfield_for_foreignkey(db_field, request, **kwargs)
 
+    def delete_queryset(self, request, queryset):
+        for activity in queryset:
+            print(activity)
+            self.delete_model(request, activity)
+
+    def delete_model(self, request, activity):
+        try:
+            activity.delete()
+            messages.success(request, f"Aktivitet \"{activity.name}\" slettet.")
+        except ValidationError as e:
+            messages.error(request, e.message)
+
+        except Exception as e:
+            messages.error(request, f"Fejl: {str(e)}")
+
     fieldsets = [
         (
             "Afdeling",

members/models/activity.py

@@ -114,6 +114,9 @@ def seats_left(self):
     def participants(self):
         return self.activityparticipant_set.count()
 
+    def invitations(self):
+        return self.activityinvite_set.count()
+
     participants.short_description = "Deltagere"
 
     def get_min_amount(self, activitytype):
@@ -146,3 +149,10 @@ def clean(self):
 
         if errors:
             raise ValidationError(errors)
+
+    def delete(self, *args, **kwargs):
+        if (self.invitations() > 0 or self.participants() > 0):
+            raise ValidationError(
+                f"Aktivitet \"{self.name}\" kan ikke slettes, da der er tilmeldte eller inviterede personer."
+            )
+        super().delete(*args, **kwargs)

members/models/activityinvite.py

@@ -22,7 +22,7 @@ class Meta:
         unique_together = ("activity", "person")
 
     activity = models.ForeignKey(
-        "Activity", on_delete=models.CASCADE, verbose_name="Aktivitet"
+        "Activity", on_delete=models.DO_NOTHING, verbose_name="Aktivitet"
     )
     person = models.ForeignKey("Person", on_delete=models.CASCADE)
     invite_dtm = models.DateField("Inviteret", default=timezone.now)