Allow overriding view authentication system

gas/views.py

@@ -83,7 +83,7 @@ class GASMixin:
     breadcrumbs = []
     actions = None
 
-    def dispatch(self, *args, **kwargs):
+    def check_user_forbidden(self):
         user = self.request.user
         roles = set(self.roles)
         roles.add(self.base_role)
@@ -93,7 +93,10 @@ class GASMixin:
                 and user.user_roles.filter(role__in=roles).count() == 0
             )
         )
-        if access_denied:
+        return access_denied
+
+    def dispatch(self, *args, **kwargs):
+        if self.check_user_forbidden():
             return HttpResponseRedirect(reverse('gas:login') + '?next={}'.format(self.request.path))
         return super().dispatch(*args, **kwargs)