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Re: draft of 209 proposal

From: Eric Prud'hommeaux <eric@w3.org>
Date: Mon, 17 Mar 2014 09:33:04 -0400
To: Julian Reschke <julian.reschke@gmx.de>
Cc: Jonathan A Rees <rees@mumble.net>, Mark Nottingham <mnot@mnot.net>, Tim Berners-Lee <timbl@w3.org>, TAG List <www-tag@w3.org>, Arnaud Hors <lehors@us.ibm.com>, Yves Lafon <ylafon@w3.org>, Philippe Le Hégaret <plh@w3.org>, Peter Linss <peter.linss@hp.com>, "Appelquist Daniel (UK)" <Daniel.Appelquist@telefonica.com>
Message-ID: <20140317133302.GA22363@w3.org>
* Julian Reschke <julian.reschke@gmx.de> [2014-03-17 11:06+0100]
> On 2014-03-13 14:45, Jonathan A Rees wrote:
> >
> >
> >
> >On Wed, Mar 12, 2014 at 10:11 PM, Mark Nottingham <mnot@mnot.net
> ><mailto:mnot@mnot.net>> wrote:
> >
> >
> >    On 8 Mar 2014, at 2:56 am, Eric Prud'hommeaux <eric@w3.org
> >    <mailto:eric@w3.org>> wrote:
> >
> >     > * Mark Nottingham <mnot@mnot.net <mailto:mnot@mnot.net>>
> >    [2014-03-07 09:25+0000]
> >     >> Hi Eric,
> >     >>
> >     >> PLH asked me to give some initial feedback on this draft. If you
> >    want proper feedback from the IETF, I’d encourage you to submit the
> >    I-D :)
> >     >
> >     > Happy to, could you tell me what the "I-D" is?
> >
> >    Internet-Draft :)
> >
> >
> >     >> First of all, I’d like to understand what you think this status
> >    code is giving you over just using a 200 with Content-Location.
> >     >
> >     > As you point out below, the semantics we want involve a redirect,
> >    specifically "I can't give you X but I can give you Y which
> >    describes it."
> >
> >    But it's not really a redirect; the semantics you want are "you
> >    asked for that, but I'm giving you this." That's 200 with a
> >    Content-Location, because the resource *is* making an assertion
> >    about something, even if it has a separate identity.
> >
> >
> >p2 3.1.4.1 #4 "If the response has a Content-Location header field and its
> >        field-value is a reference to a URI different from the effective
> >        request URI, then the sender asserts that the payload is a
> >        representation of the resource identified by the Content-Location
> >        field-value. "
> >
> >In the 209-like scenario the payload would *not* necessarily be a
> >representation of the resource identified by the Content-Location
> >field-value. Or equivalently, the sender might not want to make such a
> >warrant.
> >
> >So I don't think your suggestion to involve Content-Location in this
> >discussion is appropriate.
> >
> >Not that I'm a fan of 209, but I like using Content-Location in this
> >situation even less.
> >
> >Jonathan
> 
> Again: if you make it a 2nn status code, clients now knowing about
> the new status code will treat it just like 200. Are you ok with
> that?

I very much appreciate this question. A few of us have tried to answer
it with by looking at existing code to try to figure out what breaks
vs. what we want to break <http://www.w3.org/2014/02/2xx/tests/>. In
general, we want existing apps to work but new Linked Data tools to
consume and generate 2xx. In particular, we'd like apps which record
metadata about fetched resources to associate that metadata with the
final URL rather than the original one.

Browser's treate the result as a success, which they should as they
have no e.g. chrome artifacts which would surface the distinction
anyways. Some XDR code looks for 200 and some looks for 200-299.
A couple apps we cared about were rigorous enough to look for the
latter.



> Best regards, Julian
> 

-- 
-ericP

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Received on Monday, 17 March 2014 13:33:37 UTC

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