[wp-hackers] Atom mime type & browsers

[Danny Ayers]

[this was prompted by discussion on Apple's list, but I think the
forwarded material is worth placing in the wp-dev archives for future
ref]

I asked about workarounds for displaying Atom in browsers that didn't
recognise the media type. Basically Atom feeds SHOULD be served up
with "application/atom+xml".

There was quite a bit of back-and-forth on whether or not
"application/xml" was an acceptable substitute ("text/xml" was soundly
rejected). The thread starts here:
http://www.imc.org/atom-syntax/mail-archive/msg17802.html

The following contains a fairly comprehensive approach:

---------- Forwarded message ----------
From: John Panzer <jpanzer at aol.net>
Date: Jan 30, 2006 9:57 PM
Subject: Re: Browser behaviour

Here's my 'best effort' suggestion that we're looking to implement at AOL:

(1) All links from within feeds go to a resource of type
"application/atom+xml".
(2)  Header links (<link rel...>) in web pages to to a resource as in #1.
(3) Feed links displayed in web pages, which a user in a web browser
might click on, go to a resource of type "application/xml", which
contains exactly the same XML that would be contained in the Atom feed
resource of type "application/atom+xml", along with a style sheet that
causes said page to be rendered in a browser with subscribe links
(pointing to resource #1).  The web UI tries to guide users to subscribe
buttons first, before showing them a raw feed URL.

In other words, the application/xml content is a fallback for when
users, despite our best efforts, end up looking at XML content inside a
web browser.  I'd also be happy to make this behaviior browser-dependent
so that we serve application/atom+xml to browsers which will display it
inline with a style sheet, if there are any.

This means that users might possibly end up subscribing to something of
type application/xml if they copy and paste URL #3... but we could also
make this client dependent so that, for example, everything other than
known web browsers get application/atom+xml.  Not sure about that as
it's changing the MIME type, but I think it's changing it for a good
reason (working around what I think is a browser problem).

Comments welcomed.

-John



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http://dannyayers.com