- From: Mark Nottingham <mnot@mnot.net>
- Date: Mon, 4 Nov 2013 15:12:34 -0800
- To: "Julian F. Reschke" <julian.reschke@gmx.de>
- Cc: "Henry S. Thompson" <ht@inf.ed.ac.uk>, HTTP Working Group <ietf-http-wg@w3.org>, "apps-discuss@ietf.org Discuss" <apps-discuss@ietf.org>, "www-tag@w3.org WG" <www-tag@w3.org>
What Julian says. Reactive negotiation is very common; formats are coming up with mechanisms for it all the time (e.g., the work on srcset, etc. in the W3C web perf WG). Cheers, On 4 Nov 2013, at 2:55 pm, Julian Reschke <julian.reschke@gmx.de> wrote: > 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 out-of-date, but also this discussion appears to at least this reader 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 -- Mark Nottingham http://www.mnot.net/
Received on Monday, 4 November 2013 23:13:00 UTC