check for a model in permission and use that in treasury

apps/permission/backends.py

@@ -198,6 +198,41 @@ class PermissionBackend(ModelBackend):
     def has_module_perms(self, user_obj, app_label):
         return False
 
+    @staticmethod
+    @memoize
+    def has_model_perm(request, model, type):
+        """
+        Check is the given user has the permission over a given model for a given action.
+        The result is then memoized.
+        :param request: The current request
+        :param model: The model that the permissions shoud apply
+        :param type: The type of the permissions: view, change, add or delete
+        For view action, it is consider possible if user can view or change the model
+        """
+        # Requested by a shell
+        if request is None:
+            return False
+
+        user_obj = request.user
+        sess = request.session
+
+        if hasattr(request, 'auth') and request.auth is not None and hasattr(request.auth, 'scope'):
+            # OAuth2 Authentication
+            user_obj = request.auth.user
+
+        if user_obj is None or user_obj.is_anonymous:
+            return False
+
+        if user_obj.is_superuser and sess.get("permission_mask", -1) >= 42:
+            return True
+
+        ct = ContentType.objects.get_for_model(model)
+        if any(PermissionBackend.permissions(request, ct, type)):
+            return True
+        if type == "view" and any(PermissionBackend.permissions(request, ct, "change")):
+            return True
+        return False
+
     def get_all_permissions(self, user_obj, obj=None):
         ct = ContentType.objects.get_for_model(obj)
         return list(self.permissions(get_current_request(), ct, "view"))