init

backend/configuration/admin.py

@@ -0,0 +1,22 @@
+from django.contrib import admin
+from .models import AppConfig
+
+from trznice.admin import custom_admin_site
+
+
+class AppConfigAdmin(admin.ModelAdmin):
+    def has_add_permission(self, request):
+        # Prevent adding more than one instance
+        return not AppConfig.objects.exists()
+
+    def has_delete_permission(self, request, obj=None):
+        # Prevent deletion
+        return False
+
+    readonly_fields = ('last_changed_by', 'last_changed_at',)
+
+    def save_model(self, request, obj, form, change):
+        obj.last_changed_by = request.user
+        super().save_model(request, obj, form, change)
+
+custom_admin_site.register(AppConfig, AppConfigAdmin)