Media Categories 1.3.1 & a Trac Ticket with Patch

I didn’t have a chance to post about this, but last week I quietly released Media Categories 1.3.1, to workaround a problem which was reported to me on the support forums in the WordPress Plugin directory.

A user of the Media Categories plugin explained that some under certain circumstances, categorized media would not save properly. Here are the steps to reproduce the problem:

1. Create two categories with the same name, but different slugs.
2. Open up an attachment while Media Categories 1.3 or below are turned on. (download that version here)
3. Select the two same-name categories, and click save. WordPress will take you back to the Media Library.
4. Open the same attachment again, and click save, without having changed anything.
5. Open that attachment once more. You will find that one of the categories that had a duplicate name, is no longer selected.

The first thing I did was turn off the styling on my plugin, which hides a text field that WordPress creates when an attachment has taxonomy support and watched what it did as I went through each of the steps above. This field will take term ID’s, slugs, and names – it can take any number of terms, each separated by commas – but requires the user to manually enter them from memory, which I why I built my plugin.

Once the user has selected and saved their terms, upon re-opening the attachment, that field will always be populated by the categories name. When names are used in that field, WordPress simply tried search for that category by name,  which as we know can be non-unique. This results in WordPress chosing the first term with that name it comes across, for both instances of the name – resulting in the later on being lost. The next time you open that attachment, there’s only one instance because both were saved as the same term.

I figure this has gone unnoticed because WordPress does not natively support taxonomy for attachments, and few people use plugins that turn on that support. It’s easy to see how the original developer of the built-in text field would have thought that using the term name would be easier for end-users to deal with – however it clearly causes problems when in use.

I opened a ticket in WordPress Trac, and submitted a very modest patch that changes one line in core so that is spits out the slug instead of the name. However who knows when that ticket will be  dealt with, and we are very close to WordPress 3.4 being released, so I don’t have much hope of it being part of that release.

With that in mind I developed a fairly simple workaround which accomplishes the same goal, but by effectively re-doing what WordPress does when saving an attachment. I released it last week over the holiday weekend as Media Categories 1.3.1, and I suggest anyone using this plugin upgrade, or risk losing some of their saved data.

Thanks for reading, and thanks for the bug reports.

Update:  My patch was accepted and will be released in WordPress 3.5. As small and simple as it might be, and even though I’ve been working with WordPress professionally for over 3 years – this is the first time one of my contributions to core has been committed. Yay me.