FeedWordPress and WordPress 2.5.1 compatibility issue

I wanted to post a quick note because I have received several reports of a serious compatability issue between FeedWordPress and the most recent public release of WordPress, version 2.5.1. Although FWP is broadly compatible with the initial release of WordPress 2.5, the recent update apparently eliminates an interface function that FeedWordPress used to display a box for selecting categories in the Syndication options and the feed settings pages. Since the function no longer exists in WordPress 2.5.1, it means that a fatal PHP error (shown either by a prematurely cut-off display, or in the form of a printed PHP error message) will be triggered if you attempt to use either of these pages in the WordPress Dashboard. (As far as I know, syndication will continue to work fine with WordPress 2.5.1; the error will prevent you from changing configuration settings from within the WordPress Dashboard.)

This problem should, hopefully, be something that it won’t be too hard to fix once I am able to sit down and work on it. Unfortunately, the release came after I had left to visit family in Alabama, so I can’t get to making the fix until I return home early in the upcoming week. Once I do, I’ll release an immediate compatability fix, and then return to work on a more thorough update, which I hope to release sometime during the month of May.

I’ll check back in with y’all once I’ve gotten home.

Upgrade Downgrade: Compatibility bugs and possible quick fixes for issues with FeedWordPress after upgrading to WordPress 2.5

WordPress 2.5 was recently released, and as a result many FeedWordPress users have upgraded their blogs to the latest version of WordPress. I am currently in the process of testing for any compatability issues between WordPress 2.5 and the development version of FeedWordPress (0.993a); if I notice any definite problems, then I will make them high-priority bug fixes and try to push out the release of 0.993 as quickly as possible. (That probably means either tonight, or some time around the end of the month, depending on when I find any problems that I may find.) If you have tried using FeedWordPress with WordPress 2.5, either in version 0.992 or in the current trunk development version, and have noticed any problems since the upgrade that aren’t fixed by what I’m about to suggest, then please feel free to report them in the comments here or to me by e-mail, as you prefer. The most helpful bug reports are those that state, in as much detail as possible, (1) what precisely is going wrong, (2) under what conditions, (3) with what version of FeedWordPress, (4) under what version of PHP, and, if the problem is with syndicating posts, then (5) with which feeds at which specific URIs. If you are getting symptoms of a fatal error (either a printed error message or a blank screen where a page should be), then you can also help me out a lot by copying and pasting the contents of the error message into your report, or, if you have a blank screen, checking the bottom of your web server’s error logs to see if there is a PHP error report down there, and, if so, copying and pasting that.

That said, one of the most common sources of error reports when new versions of WordPress are released come not from a real compatability issue, but rather from the fact that, if you’re not careful, upgrading your copy of WordPress will downgrade your copy of MagpieRSS from the newer version shipped with FWP to the very old and busted version that WordPress continues, for whatever reason, to ship with new releases of WordPress.

Diagnosis

Here are the most common symptoms of this problem:

  • Some feeds (notably, feeds produced by Blogger and other Atom 1.0 feeds) stop syndicating post contents. You get the headline of the post and nothing else.
  • Some feeds (notably, those produced by blogs hosted at WordPress.com (!)) start appearing with just the capital letter A as the content of the post.
  • Categories stop being properly syndicated. Everything is placed in Uncategorized or in bizarre, mashed-up categories (only one per post) that seem to contain several category names.
  • Podcast attachments are no longer syndicated.

And so on, and so forth. If you notice these problems with your feeds just after you’ve upgraded your copy of WordPress, it’s probably because you need to re-install the MagpieRSS upgrade.

Cure

Here’s how you do that. In the FeedWordPress plugin directory (wp-content/plugins/feedwordpress/, relative to your WordPress installation), there is a directory called MagpieRSS-upgrade, which contains, or at least at one point contained, two files, rss.php and rss-functions.php. If you still have these files, you need to copy them to your WordPress wp-includes directory, where they will overwrite the older version of MagpieRSS that ships with WordPress. If you do not (because, for example, you moved them rather than copying them when you first installed FeedWordPress), then you can get new copies of these files by downloading the latest version of FeedWordPress, and extracting these two files from the archive.

Etiology and pognosis for the patient

The reason that this happens is that every installation of WordPress includes a very old version of MagpieRSS, the library that FeedWordPress uses to parse the feeds that it syndicates. As of the 2.5 release, WordPress still ships with a package derived from MagpieRSS 0.51, which is the same version it shipped with when I started work on FeedWordPress three years ago. This version of MagpieRSS is adequate for what WordPress needs it to do (basically, fetch headlines for the Dashboard from a select few feeds), but it was already outdated three years ago, and it is especially outdated now–it could not handle multiple categories; it could not handle enclosures, it could not translate feeds in alternate encodings; and, importantly, it cannot correctly handle Atom 1.0 feeds (now the default for Blogger feeds) or feeds with MediaRSS extensions (now the default for WordPress.com feeds). Unfortunately, since there is a version of MagpieRSS, which is loaded every time you load WordPress, it is hard to drop in a newer version which can do these things without causing errors from the collision in function and class names.

The solution I settled on was the bundled MagpieRSS upgrades, which in the past I sometimes described as optional, but which now really are mandatory if you hope to do any serious syndication in the modern environment. Users can avoid collisions by copying the upgrade so that it just overwrites the older version in wp-includes. Problem solved for the time being.

But the downside of this solution is that every time an upgrade of WordPress comes out, it comes out with older versions of the MagpieRSS package included, and when you overwrite all the files in wp-includes with the newer files from the WordPress release, one of the things you overwrite is your upgraded copy of rss.php. Meaning that, unless you remember to re-upgrade MagpieRSS every time you upgrade WordPress (something which is easy enough to forget), it breaks your syndication until you remember, or I remind you, to re-do the upgrade.

I frankly consider this a design flaw in FeedWordPress, but it’s not a flaw that is easy for me to fix. I am considering different ways of getting around it, and honestly the most likely solution at this point is probably simply to abandon MagpieRSS and package another feed parsing package (such as SimplePie) in the feedwordpress plugin directory, where upgrades to the WordPress core code cannot interfere with it. But doing that will involve pretty dramatically refactoring some of FeedWordPress’s internal workings, and that may take a while. In the meantime, if you have a working aggregator, you should probably apply this quick fix and see how many of your problems it solves.