Actions triggered by field change in Django

Question

How do I have actions occur when a field gets changed in one of my models? In this particular case, I have this model:

class Game(models.Model):
    STATE_C         


        

Answer 1

Django has a nifty feature called signals, which are effectively triggers that are set off at specific times:

• Before/after a model's save method is called
• Before/after a model's delete method is called
• Before/after an HTTP request is made

Read the docs for full info, but all you need to do is create a receiver function and register it as a signal. This is usually done in models.py.

from django.core.signals import request_finished

def my_callback(sender, **kwargs):
    print "Request finished!"

request_finished.connect(my_callback)

Simple, eh?