Resolve "Reinvestigate how to do global permissions"

Closes #344 (closed)

aleksis/core/checks.py

@@ -3,7 +3,7 @@ from typing import Optional
 import django.apps
 from django.core.checks import Tags, Warning, register
 
-from .mixins import ExtensibleModel, PureDjangoModel
+from .mixins import ExtensibleModel, GlobalPermissionModel, PureDjangoModel
 from .util.apps import AppConfig
 
 
@@ -39,7 +39,10 @@ def check_app_configs_base_class(
 def check_app_models_base_class(
     app_configs: Optional[django.apps.registry.Apps] = None, **kwargs
 ) -> list:
-    """Check whether all app models derive from AlekSIS's base ExtensibleModel."""
+    """Check whether all app models derive from AlekSIS's allowed base models.
+
+    Does only allow ExtensibleModel, GlobalPermissionModel and PureDjangoModel.
+    """
     results = []
 
     if app_configs is None:
@@ -47,14 +50,21 @@ def check_app_models_base_class(
 
     for app_config in filter(lambda c: c.name.startswith("aleksis."), app_configs):
         for model in app_config.get_models():
-            if ExtensibleModel not in model.__mro__ and PureDjangoModel not in model.__mro__:
+            if (
+                ExtensibleModel not in model.__mro__
+                and PureDjangoModel not in model.__mro__
+                and GlobalPermissionModel not in model.__mro__
+            ):
                 results.append(
                     Warning(
-                        f"Model {model._meta.object_name} in app config {app_config.name} does"
-                        "not derive from aleksis.core.mixins.ExtensibleModel.",
+                        f"Model {model._meta.object_name} in app config {app_config.name} does "
+                        "not derive from aleksis.core.mixins.ExtensibleModel "
+                        "or aleksis.core.mixins.GlobalPermissionModel.",
                         hint=(
-                            "Ensure all models in AlekSIS use ExtensibleModel as base."
-                            "If your deviation is intentional, you can add the PureDjangoModel"
+                            "Ensure all models in AlekSIS use ExtensibleModel (or "
+                            "GlobalPermissionModel, if you want to define global permissions) "
+                            "as base. "
+                            "If your deviation is intentional, you can add the PureDjangoModel "
                             "mixin instead to silence this warning."
                         ),
                         obj=model,