code: def action_log_update(sender, instance, **kwargs):
      
      if instance.pk is not None:
          try:
              old = sender.objects.get(pk=instance.pk)
          except sender.DoesNotExist:
              pass
          else:
              new = instance
  
              changes = model_instance_diff(old, new)
  
              # Log an entry only if there are changes
              if changes:
                  log_entry = LogAction.objects.create_log_action(
                      instance=instance,
                      action=LogAction.UPDATE,
                      changes=json.dumps(changes),
                  )
docs: Signal receiver that creates a log entry when a model instance is changed and saved to the database.
  
      Direct use is discouraged, connect your model through :py:func:`actionslog.registry.register` instead.