Missing group message

* adds group checker decorator for adding a message informing about missing group privileges

konova/decorators.py

@@ -46,6 +46,25 @@ def superuser_required(function):
     return wrap
 
 
+def any_group_check(function):
+    """
+    Checks for any group membership. Adds a message in case of having none.
+
+    """
+    @wraps(function)
+    def wrap(request, *args, **kwargs):
+        user = request.user
+        # Inform user about missing group privileges!
+        groups = user.groups.all()
+        if not groups:
+            messages.info(
+                request,
+                _("+++ Attention: You are not part of any group. You won't be able to create, edit or do anything. Please contact an administrator. +++")
+            )
+        return function(request, *args, **kwargs)
+    return wrap
+
+
 def default_group_required(function):
     """
     A decorator for functions which shall only be usable for users of specific groups.