Roy Tang

I actually had some trouble using django-pingback on my custom blog engine; the django-pingback documentation is mostly fine, but there were some caveats that I had to discover myself through a bit of debugging:

• The URL specified for the XML-RPC endpoint in the HTML head needs to be a full absolute url including domain, i.e. http://roytang.net/xmlrpc/, which gave me trouble when I was trying to test using localhost pinging to an online server. I eventually just decided to set it up, deploy on webfaction and test it online before I redirected the domain name.

• The documentation mentioned that the pingback handler needs to have the same arguments as the detail view for the post, so I wrote it as follows:

  # exactly same arguments as 'details' view.
  def pingback_blog_handler(catslug, year, month, slug, **kwargs):
      cat = Category.objects.get(slug=catslug)
      return Post.pub_objects.get(date__year=year, date__month=month, slug=slug, category=cat, published=True)
  

  But it wasn’t exactly working for me, for some reason the function wasn’t being called. After some debugging I found that I needed to use named parameters for catslug, year, month, slug in the URLConf for the post permalink in order for this to work. I’m not sure if this was because I was doing it wrong or it’s some sort of undocumented requirement.

• The pingback client was throwing a KeyError whenever a post I made would have anchor tags without an href attribute. Granted that there isn’t much point in having an anchor tag without the href, but the code shouldn’t just choke on it. I modified the following line in client.py:

    links = [a['href'] for a in soup.findAll('a') if is_external(a['href'], url)]
  

  Adding the check for the href attribute:

    links = [a['href'] for a in soup.findAll('a') if a.has_key('href') and is_external(a['href'], url)]
  

  Those are all the changes I made to get pingbacks working. I hope they’re still working now, as I haven’t received any pingbacks since the django version of this blog went live >.