Question

I have a following (simplified) class in models.py:

class Order( models.Model ) :
    status       = models.CharField( max_length = 135, blank = True )
    t_status     = models.DateTimeField( null = True, blank = True )
    user_status  = models.ForeignKey( User, null = True, blank = True )
    t_created    = models.DateTimeField( auto_now_add = True )
    t_modified   = models.DateTimeField( auto_now = True )

How do I set t_status to be a timestamp (much like t_modified) when the value of t_status changes? Note that t_status can be blank. t_status would normally changed from NULL to the string approved or rejected. user_status is the person that approves or rejects this order.

Answer 1

See django-dirtyfields.

class Order(DirtyFieldsMixin, models.Model):
    ...

def order_pre_save(sender, instance):
    if "status" in instance.get_dirty_fields():
        instance.t_status = datetime.datetime.now()

pre_save.connect(order_pre_save, sender=Order)