fix save mrss

apps/core/admin.py

 from django.contrib import admin
-from django.conf import settings
 from django.contrib.contenttypes.admin import GenericTabularInline
 
 from . import models, forms
@@ -63,10 +62,6 @@ class PlayListAdmin(admin.ModelAdmin):
             return [TagInline]
         return []
 
-    def save_model(self, request, obj, form, change):
-        obj.mrss = f'{settings.DOMAIN_NAME}/api/playlist/{obj.id}/mrss'
-        super().save_model(request, obj, form, change)
-
 
 class CategoryAdmin(admin.ModelAdmin):
     list_display = ['id', 'name', ]

apps/core/apps.py

@@ -4,3 +4,6 @@ from django.apps import AppConfig
 class CoreConfig(AppConfig):
     default_auto_field = 'django.db.models.BigAutoField'
     name = 'apps.core'
+
+    def ready(self):
+        import apps.core.signals

apps/core/signals.py

+from django.conf import settings
+from django.dispatch import receiver
+from django.db.models.signals import post_save
+
+from . import models
+
+
+@receiver(post_save, sender=models.Playlist)
+def save_playlist_mrss(sender, instance, created, **kwargs):
+    if created:
+        instance.mrss = f'{settings.DOMAIN_NAME}/api/playlist/{instance.id}/mrss'
+        instance.save()