Working with Disqus

Since I’ve migrated this blog to PieCrust and all its comments to Disqus I’ve run into a few problems that took me some time to figure out (although I got help from the nice Disqus guys). Those problems come down to the following information which was not quite clear to me even after reading their documentation several times:

• The disqus_identifier value gives a unique name to a thread.
• The disqus_location value indicates the URL(s) at which a given thread can be found.
• A thread can be used by several URLs, but no URL can be used by more than one thread.

The first 2 points are pretty straightforward, but that last one was the tricky one. Basically (at the time of this writing, obviously) if you have 2 threads with 2 correctly unique identifiers that were created both with the same URL, your page at that URL will show all kinds of weird behaviours, from never loading any comments (you get the “Disqus loading” icon animation) to loading one of the thread regardless of what disqus_identifier you specified on that page. You would think that identifier would, well, identify exactly what thread you wanted to display, but no, the URL from which it is loaded apparently also plays an important role.

This means, for example, that you can’t display more than one thread on a single page, although the Disqus guys told me this limitation will be removed in a few months.

Another little thing to look for is the subtle distinction between http://example.com/some/url and http://example.com/some/url/ (note the trailing slash character at the end of the second URL). Those URLs are effectively different, as far as Disqus is concerned. This is especially important for statically generated websites since the actual URL of a page or post is http://example.com/some/url/index.html, so there could be at least 3 correct ways to access the same page. Hopefully, as long as you don’t have some weird address collision, you won’t run into the problem mentioned above (which I ran into because I was messing around with the very handy Disqus Python bindings to batch rename and re-identify my threads).

Hopefully this will save somebody some head-scratching.