title: Django Signal User when is registred with facebook
body: <p>I am asking for how to add a Signal in model <strong>User</strong> and know if that user was registred through <strong>Facebook</strong>, I mean, if an new <strong>User</strong> is created in Django with <strong>Facebook</strong> I want to catch this event and save a new Customer model.
  I believe that could be something like That:</p>
  
  <pre><code># SIGNALS AND LISTENERS
  from django.contrib.auth.models import User
  from django.db.models import signals
  from django.dispatch import dispatcher
  form customers.model import Customer
  
  # User
  def user_post_save(sender, instance, signal, *args, **kwargs):
      # Creates user profile
      if user # &lt;- SOMETHGING LIKE IF USER IS LOGGED IN WITH FACEBOOK...
          customer = Customer.objects.get_or_create(owner=instance)
  
  dispatcher.connect(user_post_save, signal=signals.post_save, sender=User)
  </code></pre>
  
  <p>In the comment you can see what I need.
  Thanks for your help.</p>