W3C home > Mailing lists > Public > www-tag@w3.org > October 2007

Re: Subgroup to handle semantics of HTTP etc?

From: <noah_mendelsohn@us.ibm.com>
Date: Mon, 22 Oct 2007 10:16:20 -0400
To: wangxiao@musc.edu
Cc: Alan Ruttenberg <alanruttenberg@gmail.com>, Dan Connolly <connolly@w3.org>, "Booth, David (HP Software - Boston)" <dbooth@hp.com>, Jonathan A Rees <jar@mumble.net>, "Williams, Stuart (HP Labs, Bristol)" <skw@hp.com>, Tim Berners-Lee <timbl@w3.org>, W3C-TAG Group WG <www-tag@w3.org>
Message-ID: <OFE5B8FF80.9143B649-ON8525737C.004DD20A-8525737C.004E4293@lotus.com>

Xiaoshu Wang writes:

> Hmm.. not really.  I think AWWW's opinion is that for some resource,
> i.e., the information resource, T=R.

If that were the case, then why would we allow content negotiation based 
on media-type, language (French, English, Chinese, etc.)?  Furthermore, I 
think it's pretty well accepted that a 200 is an acceptable status code 
for a GET to a clock resource.  With such a resource we can see that the 
same URI (http://example.com/clock)  returns different representations 
each time it's accessed.   I find that a useful example to motivate the 
distinction between an information resource and its representation(s).

Furthermore, to reiterate the point about content negotiation, I think it 
would be quite acceptable for that clock to return a string like "10:03 AM 
EDT October 23, 2007" if asked for text/plain, but to return the image of 
a suitable clock face if asked for image/jpeg.  All of these illustrate 
the lack of one-to-one relationship between an information resource and 
its representations, at least in the general case.


Noah Mendelsohn 
IBM Corporation
One Rogers Street
Cambridge, MA 02142
Received on Monday, 22 October 2007 14:15:03 UTC

This archive was generated by hypermail 2.4.0 : Friday, 17 January 2020 22:56:18 UTC