refactor(access): cache app settings during model fetch

ref: #469 #471

app/access/models.py

@@ -143,6 +143,8 @@ class TenancyManager(models.Manager):
     This manager specifically caters for the multi-tenancy features of Centurion ERP.
     """
 
+    _app_settings: any = None
+
 
     def get_queryset(self):
         """ Fetch the data
@@ -179,15 +181,17 @@ def get_queryset(self):
 
         if request:
 
-            from settings.models.app_settings import AppSettings
+            if not self._app_settings:
 
-            app_settings = AppSettings.objects.prefetch_related('global_organization').get(
-                owner_organization = None
-            )
+                from settings.models.app_settings import AppSettings
+
+                self._app_settings = AppSettings.objects.prefetch_related('global_organization').get(
+                    owner_organization = None
+                )
 
-            if app_settings.global_organization:
+            if self._app_settings.global_organization:
 
-                user_organizations += [ app_settings.global_organization.id ]
+                user_organizations += [ self._app_settings.global_organization.id ]
 
             # user = request.user._wrapped if hasattr(request.user,'_wrapped') else request.user