So the average-joe RSS is binary ie either you subscribe to a feed or you don’t. This approach results in a ridiculous amount of junk in our inbox. What if we could define the feed that we would like to subscribe to? Thanks to the stellar django syndication framework and django filters, I was able to hack together a fix.

If you have a Book model like so:

class Book(models.Model):
        name = models.CharField(max_length=256)
        pages = models.IntegerField()

    def __unicode__(self):
        return self.name

A django filters FilterSet like so:

class BookFilterSet(django_filters.FilterSet):
        pages = NumberFilter(lookup_type='lt')
        class Meta:
            model = Book
            fields = ['pages']

A FilteredFeed class like so:

class BookFilteredFeed(BaseFilteredFeed):
        model = Book
        filter_set = BookFilterSet
        title = "BookFeed"
        link = "http://localhost:8000"
        description = "Alerts for new books!"

        def item_link(self, item):
            return reverse('book_detail', 
                           args=[item.id])

Hook up the necessary urls like so:

urlpatterns = patterns('',
        url(r'^books/feed$', 
            BookFilteredFeed.as_view(), 
            name='book_feed'),
    )

And finally, if we have the following 3 books in our DB:

  1. Introduction to Python (100 pages)
  2. Introduction to C (300 pages)
  3. Javascript - The good parts (300 pages)

Hitting http://localhost:8000/books/feed will give you an RSS feed includes:

  • Introduction to Python
  • Introduction to C
  • Javascript - The good parts

And hitting http://localhost:8000/books/feed?pages=200 will give you an RSS feed that just includes:

  • Introduction to Python

You users will forever remain grateful for sparing them the deluge that follows a binary subscription. You will be hailed the king of syndication, worshipped as a rock star and live happily ever after. The best part is that it takes a minute to get started:

pip install django_filtered_feed

Followed ofcourse by including filtered_feed in your INSTALLED_APPS.

INSTALLED_APPS = (
        ...
        'filtered_feed',
        ...
    )