Nikolas 'Atrus' Coukouma wrote:
Using @rel with any linking element is perfectly valid and has been for years. @rel not being supported for anything other than the link element itself has also been an outstanding bug for just as long. There's lot of debate attached to at least one Mozilla bug (#57399 [1] - filed on 2000-10-20).
Can we agree that this should be supported, but currently isn't? Unless there's a compelling reason not to, I think we might as well allow autodiscovery via either element. Any implementation guide should recommend duplicating the information in the interest of autodiscovery actually working.
[1] https://bugzilla.mozilla.org/show_bug.cgi?id=57399
-1 to saying in the spec that you can use either element, and in the guide saying to use both if you want it to work, not just look pretty.
As I remember it, when RSS autodiscovery started this cowpath, aggregator developers generally didn't have an SGML parser handy, and weren't especially happy about the idea of having to write their own HTML parser. Finding one (or a few) of relatively few <link>s in the first bit of the document feels a lot easier than having to look at every <a> in the whole document.
Now? I'd say most don't have an SGML parser handy, and won't be especially happy about writing their own HTML parser. It's fairly rare for someone to comment out bits of their <head>, and quite common for them to comment out huge swaths of their <body>, including things a template came with, like <a href="../xml/index.atom" rel="feed">Atom feed</a>, with no thought that something will be seeing and using that invisible link with an incorrect path. I added Atom autodiscovery to my current aggregator, Feed on Feeds, with a ten second copy/paste/change mime-type of the results of it using a regular expression on the HTML. If instead I had to correctly parse the entire HTML document, I'd... switch to something in Python, I guess.
Then, since I foolishly took the Firefox bug for better autodiscovery, I'll also need to do it where I do have an excellent HTML parser, but I have to do it on every single page that every single Firefox user loads, whether or not they have any interest in feeds, or subscribed to the feed ten thousand loads of that particular page ago. <link> is easy, we've got a DOMLinkAdded event and most pages have very few of them. <a>? Well, the performance hit probably won't be noticeable on most pages.
Phil Ringnalda
