W3C home > Mailing lists > Public > semantic-web@w3.org > July 2008

Re: ConNegging on Description Pages (was RE: Southampton Pub data as linked open data)

From: Ted Thibodeau Jr <tthibodeau@openlinksw.com>
Date: Wed, 30 Jul 2008 12:58:29 -0400
To: Richard Cyganiak <richard@cyganiak.de>
Cc: "Tom Heath" <Tom.Heath@talis.com>, "Kingsley Idehen" <kidehen@openlinksw.com>, "John Goodwin" <John.Goodwin@ordnancesurvey.co.uk>, <public-lod@w3.org>, <semantic-web@w3.org>
Message-ID: <E1KOF7Q-0000tt-0r@maggie.w3.org>

Hi, Richard --

* Richard Cyganiak [7/30/08 3:52 PM +0100] wrote:
> Again: The TAG disagrees.

Actually, I think what I said earlier is in complete agreement with
the TAG.  See section 2.1.1 --

   2. *If no content negotiation is in place,* serve a canonical
      representation (generic resource) of the content at
      http://example.com/ubiquity/resource

(I've added the first-clause emphasis.)

(Yes, this was nominally written about "Desktop" and "Mobile"
 versions of the same page, but what better analogy is there for
 different formats of the same information?  I don't think the
 later language variant discussion applies...)


> http://www.w3.org/2001/tag/doc/alternatives-discovery.html
>
> Content negotiation is for selecting between different variants of a
> *single* resource. It's not for redirecting you all over the place.

Yes.  But what resource did you request?

Do you think that requesting http://revyu.com/people/tom/about
with "Accept: application/rdf+xml" is the same as requesting
http://revyu.com/people/tom/about/rdf with "Accept: text/html"?
Or that either of these is the same as requesting either resource
with *no* Accept: header?

I don't.

I think that when I request http://revyu.com/people/tom/about/rdf
with "Accept: text/html", I should get an HTML representation of
the resource at that address (which may not be an HTML representation
of RDF/XML, as this URL does not say rdfxml -- so there are many
possible ways it could be serialized by default).

When I request it with "Accept: application/rdf+xml", I should
get an RDF/XML serialization, again, of the resource at that
location -- which is not the same as the resource of that name!

If I just want the canonical resource with the name
http://revyu.com/people/tom/about/rdf ?  I should not use *any*
Accept: header -- I should just take what the server gives --
which I believe in this case would be the RDF/XML serialization
of http://revyu.com/people/tom/about -- the same as I would get
if I requested http://revyu.com/people/tom/about with
"Accept: application/rdf+xml".

Be seeing you,

Ted




-- 
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| Q: Are you sure?
| | A: Because it reverses the logical flow of conversation.
| | | Q: Why is top posting frowned upon?

Ted Thibodeau, Jr.           //               voice +1-781-273-0900 x32
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Received on Wednesday, 30 July 2008 17:27:32 GMT

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