Add hook to update group permission roles

(doesn't do anything yet)

InvenTree/users/apps.py

@@ -1,8 +1,33 @@
 # -*- coding: utf-8 -*-
 from __future__ import unicode_literals
 
+from django.db.utils import OperationalError, ProgrammingError
+
 from django.apps import AppConfig
 
 
 class UsersConfig(AppConfig):
     name = 'users'
+
+    def ready(self):
+
+        try:
+            self.assign_permissions()
+        except (OperationalError, ProgrammingError):
+            pass    
+
+    def assign_permissions(self):
+
+        from django.contrib.auth.models import Group
+        from users.models import RuleSet, update_group_roles
+
+        # First, delete any rule_set objects which have become outdated!
+        for rule in RuleSet.objects.all():
+            if rule.name not in RuleSet.RULESET_NAMES:
+                print("need to delete:", rule.name)
+                rule.delete()
+
+        # Update group permission assignments for all groups
+        for group in Group.objects.all():
+
+            update_group_roles(group)