Mercurial > public > sg101
annotate weblinks/signals.py @ 917:0365fdbb4d78
Fix app conflict with messages.
Django's messages app label conflicts with our messages app.
We can't easily rename our label as that will make us rename database tables.
Since our app came first we'll just customize Django messages label.
For Django 1.7.7 upgrade.
| author | Brian Neal <bgneal@gmail.com> |
|---|---|
| date | Mon, 06 Apr 2015 20:02:25 -0500 |
| 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') |