[Dominique Hazael-Massieux] Re: W3C Systems Team input on Apache conditional redirects

[Forwarded in its entirety with Dom's permission.]

Subject: Re: advice solicited by SWD WG on apache conditional redirects
From: Dominique Hazael-Massieux <dom@w3.org>
To: "Ralph R. Swick" <swick@w3.org>
Date: Tue, 15 Jan 2008 09:00:47 +0100


Le lundi 14 janvier 2008 à 16:23 -0500, Ralph R. Swick a écrit :
> Webmasters, etc. -- any comments you might have on
> the use of RewriteCond in general, or the use of RewriteCond
> specifically as the SWD WG proposes, would be appreciated.

The use of rewritecond is as common as the use of the rewriterules
modules; generally speaking, it is pretty common on serious hosting
companies, but not ubiquitous - for instance, the hosting service
provided by my ISP doesn't allow rewrite rules.

One issue with doing content negotiation with rewriterules is that the
HTTP Vary header doesn't get set, so a client won't have any clue that
it could have gotten a different response with a different Accept
header.

Also, parsing properly the Accept header using the regexp available with
RewriteCond is actually quite a challenge; in the example given in the
spec (e.g. [6]), a client sending an Accept header set to
application/xhtml+xml;q=0 (which means anything but XHTML) would get the
XHTML response.

(it usually also creates issues with caching, but since HTTP 303
responses are not cacheable, this is not a problem in this case)

I would argue that the most ubiquitous deployment solution might well be
using a PHP script to handle the content negotiation, although off the
top of my head this would also probably requires some Apache magic, and
probably wouldn't be really less onerous than the MultiViews solution
(although, again, probably much more available on most hosting servers).

Dom

> [1] http://www.w3.org/TR/2006/WD-swbp-vocab-pub-20060314/
> [2] http://www.w3.org/2006/07/SWD/recipes/draft-20071203
> [3] http://lists.w3.org/Archives/Public/public-swbp-wg/2006Feb/0076
> [4] http://www.w3.org/2006/07/SWD/track/issues/24
> [5] http://www.w3.org/2007/10/09-swd-minutes.html#item04

6. http://www.w3.org/2006/07/SWD/recipes/draft-20071203#recipe3s4

Received on Tuesday, 15 January 2008 15:05:10 UTC