Django - how can I get permalink to work with "throwaway" slug

Question

I'm trying to add slugs to the url in my django app, much like SO does.

Currently, I have pages that work just fine with a url like this:

http://example.com/foo/123/

I'd like to add 'slugified' urls like so:

http://example.com/foo/123/foo-name-here

I can get it to work just fine, by simply modifying the urlconf and adding a throwaway value to the view function:

#urls.py

ulpatterns = patterns('project.app.views',
    url(r'^foo/(?P<foo_id>\d+)/(?P<name_slug>\w+)/$', 'foo_detail', name='foo_detail'),
)

#views.py:

def foo_detail(request, foo_id, name_slug):
    # stuff here, name slug is just discarded

Visting the url with the slug works just fine.

However, my problem is when I am using @models.permalink.

For my Foo model, I used to have the following, which worked just fine:

@models.permalink
def get_absolute_url(self):
    return ('foo_detail', [str(self.id),])

However, after my change, whenever I call {{ foo.get_absolute_url }} in my templates, the result is always an empty string.

I have tried the following two replacements for get_absolute_url, neither of which is working:

from django.template.defaultfilters import slugify

# attempt 1
@models.permalink
def get_absolute_url(self):
    return ('foo_detail', [str(self.id), slugify(self.name)])

# attempt 2
@models.permalink
def get_absolute_url(self):
    return ('foo_detail', (), {
        'foo_id': str(self.id), 
        'name_slug': slugify(self.name),
    })

Note that if I add a print slugify(self.name) before returning, the slugified name is showing up in the console just fine.

When invoking {{ foo.get_absolute_url }} in my templates, the result is always an empty string, and I don't get any errors.

I know I could replace the method with return '/foo/%s/%s' % (str(self.id), slugify(self.name)), but I'm trying to get the permalink working so that my URL is only defined in one place. What am I doing wrong?

Answer 1

One thing to check for, because I also ran into this problem:

(?P<name_slug>\w+)

Is slugify adding hyphens anywhere? If so the regex won't match, hypens are a non-word character. To fix use [\w-]+ or similar.