Blogroll is back – on steroids

I finally got around to adding an excerpt of the list of blogs I’m regularly reading to the navigation bar to the right.

The list is somewhat special as it’s auto-updating: It refereshes every 30 minutes and displays a list of blogs in descending order of last-updated-time.

Adding the blogroll was a multi step process:

At first, I thought adding the Serendipity blogroll plugin and pointing it to my Newsgator subscription list (I’m using Newsgator to always have an up-to-date read-status in both Net News Wire and FeedDemon) was enough, but unfortunately, that did not turn out to be the case.

First, the expat module of the PHP installation on this server has a bug making it unable to parse files with the unicode byte order mark at the beginning (basically three bytes telling your machine if the document was encoded on a little- or big-endian machine). So it was clear that I had to do some restructuring of the OPML-feed (or patching around in the s9y plugin, or upgrading PHP).

Additionally, I wanted the list to be sorted in a way that the blogs with the most recent postings will be listed first.

My quickly hacked-together solution is this script which uses a RSS/Atom-parser I took from WordPress, which means that the script is licensed under the GNU GPL (as the parser is).

I’m calling it from a cron-job once per 30 minutes (that’s why the built-in cache is disabled on this configuration) to generate the OPML-file sorted by the individual feeds update time stamp.

That OPML-file then is fed into the serendipity plugin.

The only problem I now have is that the list is unfairly giving advantage to the aggregated feeds as these are updated much more often than individual persons blogs. In the future I will thus either create a penalty for these feeds, remove them from the list or just plain show more feeds on the page.

Still, this was a fun hack to do and fulfills its purpose. Think of it: Whenever I add a feed in either Net News Wire or FeedeDemon, it will automatically pop up on the blogroll on gnegg.ch – this is really nice.

On a side note: I could have used the Newsgator API to get the needed information faster and probably even without parsing the individual feeds. Still, I went the OMPL-way as that’s an open format making the script useful for other people or for me should I ever change the service.