annotate weblinks/signals.py @ 767:a4ae99359286

Added a bio app test for changing your avatar.
author Brian Neal <bgneal@gmail.com>
date Mon, 20 Jan 2014 20:04:25 -0600
parents ee87ea74d46b
children
rev   line source
bgneal@202 1 """Signals for the weblinks application.
bgneal@202 2 We use signals to compute the denormalized category counts whenever a weblink
bgneal@202 3 is saved."""
bgneal@202 4 from django.db.models.signals import post_save
bgneal@202 5 from django.db.models.signals import post_delete
bgneal@202 6
bgneal@202 7 from weblinks.models import Category, Link
bgneal@202 8
bgneal@202 9
bgneal@202 10 def on_link_save(sender, **kwargs):
bgneal@202 11 """This function updates the count field for all categories.
bgneal@202 12 It is called whenever a link is saved via a signal.
bgneal@202 13 """
bgneal@202 14 if kwargs['created']:
bgneal@202 15 # we only have to update the parent category
bgneal@202 16 link = kwargs['instance']
bgneal@202 17 cat = link.category
bgneal@202 18 cat.count = Link.public_objects.filter(category=cat).count()
bgneal@202 19 cat.save()
bgneal@202 20 else:
bgneal@202 21 # update all categories just to be safe (an existing link could
bgneal@202 22 # have been moved from one category to another
bgneal@202 23 cats = Category.objects.all()
bgneal@202 24 for cat in cats:
bgneal@202 25 cat.count = Link.public_objects.filter(category=cat).count()
bgneal@202 26 cat.save()
bgneal@202 27
bgneal@202 28
bgneal@202 29 def on_link_delete(sender, **kwargs):
bgneal@202 30 """This function updates the count field for the link's parent
bgneal@202 31 category. It is called when a link is deleted via a signal.
bgneal@202 32 """
bgneal@202 33 # update the parent category
bgneal@202 34 link = kwargs['instance']
bgneal@202 35 cat = link.category
bgneal@202 36 cat.count = Link.public_objects.filter(category=cat).count()
bgneal@202 37 cat.save()
bgneal@202 38
bgneal@202 39
bgneal@260 40 post_save.connect(on_link_save, sender=Link, dispatch_uid='weblinks.signals')
bgneal@260 41 post_delete.connect(on_link_delete, sender=Link, dispatch_uid='weblinks.signals')