W3C home > Mailing lists > Public > ietf-http-wg@w3.org > October to December 2013

Re: Request that the WG reconsider section 3.4: Content Negotiation

From: Julian Reschke <julian.reschke@gmx.de>
Date: Mon, 04 Nov 2013 23:55:23 +0100
Message-ID: <527825DB.6010105@gmx.de>
To: "Henry S. Thompson" <ht@inf.ed.ac.uk>, ietf-http-wg@w3.org
CC: apps-discuss@ietf.org, www-tag@w3.org
On 2013-11-04 17:53, Henry S. Thompson wrote:
> It's my impression that content negotiation hasn't turned out to play
> the kind of significant role in Web Architecture in general, or in
> HTTP use in particular, that was expected for it.
>
> I think the section on conneg in p2-semantics [1] is so out-of-step
> with actually deployment, usage and expectations that to publish it as
> it stands would be a serious mistake.
>
> In particular, the discussion of the relative disadvantages of the
> newly (re-)named 'proactive' and 'reactive' variants are not only
> out-of-date, but also this discussion appears to at least this reader
> to amount to a recommendation for 'reactive' negotiation.  Yet as far
> as I can tell no user agents _or_ servers actually support this
> approach today, as it's described here.
>
> I was sufficiently concerned about this question to undertake a
> moderately extensive empirical investigation [2].  To summarise
> perhaps too briefly, I found _no_ evidence of the use of reactive
> conneg in over 75 million HTTP request/response exchanges.
> ...

Reactive conneg isn't just about 300s and 406s. Another example would be 
a representation returned with a 200 response that contains links to 
alternate versions of the content. That's what the

"If the user agent is not satisfied by the initial response 
representation, it can perform a GET request on one or more of the 
alternative resources, selected based on metadata included in the list, 
to obtain a different form of representation for that response. 
Selection of alternatives might be performed automatically by the user 
agent or manually by the user selecting from a generated (possibly 
hypertext) menu."

in 
<http://greenbytes.de/tech/webdav/draft-ietf-httpbis-p2-semantics-24.html#rfc.section.3.4.2.p.1> 
is about.

Best regards, Julian
Received on Monday, 4 November 2013 22:55:53 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 1 March 2016 11:11:19 UTC