Save object & link logging entry

def save_callback(sender, instance, created, update_fields, **kwargs):
    """Save object & link logging entry"""
    if validate_instance(instance):
        status = 'add' if created is True else 'change'
        change = ''

        if status == 'change' and 'al_chl' in instance.__dict__.keys():
            changelog = instance.al_chl.modification
            change = ' to following changed: {}'.format(changelog)

        processor(status, sender, instance, update_fields, addition=change)