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RE: lcsh.info RDFa SKOS and content negotiation - use of RDF-style # IDs in RDFa?

From: Williams, Stuart (HP Labs, Bristol) <skw@hp.com>
Date: Fri, 3 Oct 2008 09:20:28 +0000
To: Dan Brickley <danbri@danbri.org>, RDFa <public-rdf-in-xhtml-tf@w3.org>, "www-tag@w3.org WG" <www-tag@w3.org>
CC: Ed Summers <ehs@pobox.com>
Message-ID: <233101CD2D78D64E8C6691E90030E5C81B6CF1B71A@GVW1120EXC.americas.hpqcorp.net>

Hello Dan,

Granted that this is not a content-negotiation case, but I think that sectiion 3.2.2 of Webarch [1] may be relevant here, particularly the 3rd situation described therein.

The XHTML+RDFa representation returned here does not *define* a target for the #concept fragment identifier - were the an id="concept" on the div there would be an inconsistency. The representation conveys assertions *about*  http://lcsh.info/sh85112589#concept, wisely IMO avoiding the about="#concept" form which would take us into same document reference territory.

Certainly there's a little squinting going on here - but I think that unless one is actually making assertions about 'fragments' of the document, then its ok as long as the references *do not* resolve to a hypertext anchor in the document [aside: I'd also avoid naming things with names that look like xpointer expressions too :-)].

I think that the relevant media-type registrations could (and probably should) be brought into line.

Stuart
--
[1] http://www.w3.org/TR/webarch/#frag-coneg

Hewlett-Packard Limited registered Office: Cain Road, Bracknell, Berks RG12 1HN
Registered No: 690597 England


> -----Original Message-----
> From: www-tag-request@w3.org [mailto:www-tag-request@w3.org]
> On Behalf Of Dan Brickley
> Sent: 30 September 2008 11:50
> To: RDFa; www-tag@w3.org WG
> Cc: Ed Summers
> Subject: lcsh.info RDFa SKOS and content negotiation - use of
> RDF-style # IDs in RDFa?
>
>
>
> Looks like http-range-14 still haunts us. I'm looking for some best
> practice advice for using "#blahblah" URI IDs in RDFa content...
>
> Backstory -
>
> Edd Summers has put up a great site at http://lcsh.info/
>
> It has one page for each concept listed in the Library of Congress
> Subject Headings, eg. http://lcsh.info/sh85112589 is a URI for a
> document about the LCSH heading "Religion and the Humanities".
>
> There is RDFa in the HTML page, as well as a complete
> NTriples zip-file
> download of the dataset. The RDFa uses a #concept URI to identify the
> abstract concept that the document is describing with SKOS.
>
> <div class="concept" about="http://lcsh.info/sh85112589#concept"
> typeof="skos:Concept">
>
> The document also has an RDF/XML representation available by content
> negotiation. While the triples differ a little (Ed - is this a bug?),
> they all talk about the SKOS concepts via identifiers that
> take the main
> page's URI and append '#concept'.
>
> Is it TAG-acceptable to use a URI in this manner, when
> http://lcsh.info/sh85112589 is the URI for a document
> available in RDFa
> XHTML rather than RDF/XML? What does
> "http://lcsh.info/sh85112589#concept" name? How do we 'follow
> our nose'
> here? Should the media type definition for RDFa allow the
> assignation of
> URIs to things other than chunks of markup?
>
> Does anyone have a suggestion for how if at all this should be done
> differently? My sense is that the HTML spec as-is doesn't
> license us to
> assign URIs in this way. And since #foo is to be interpreted w.r.t. to
> the (set of?) media types we get back as HTTP representations, there
> seems to be a tension here between using conneg and using rdfa and
> avoiding having to do http 303 redirects...
>
> cheers,
>
> Dan
>
>
>
> curl -s http://lcsh.info/sh85112589 | rapper -i rdfa - file:
>
> rapper: Parsing file <stdin> with parser rdfa and base URI file:
> rapper: Serializing with serializer ntriples and base URI file:
>
> <file:> <http://www.w3.org/1999/xhtml/vocab#alternate>
> <http://lcsh.info/sh85112589.rdf> .
> <file:> <http://www.w3.org/1999/xhtml/vocab#alternate>
> <http://lcsh.info/sh85112589.n3> .
> <file:> <http://www.w3.org/1999/xhtml/vocab#alternate>
> <http://lcsh.info/sh85112589.json> .
> <http://lcsh.info/sh85112589#concept>
> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
> <http://www.w3.org/2004/02/skos/core#Concept> .
> <http://lcsh.info/sh85112589#concept>
> <http://www.w3.org/2004/02/skos/core#prefLabel> "Religion and the
> humanities" .
> <http://lcsh.info/sh85112589#concept>
> <http://www.w3.org/2004/02/skos/core#altLabel> "Humanities
> and religion" .
> <http://lcsh.info/sh85112589#concept>
> <http://purl.org/dc/terms/created>
> "1986-02-11" .
> <http://lcsh.info/sh85112589#concept>
> <http://purl.org/dc/terms/modified> "1986-02-11T00:00:00" .
> rapper: Parsing returned 8 triples
>
>
> curl -H "Accept: application/rdf+xml" -s http://lcsh.info/sh85112589 |
> rapper -i rdfxml - file:
>
> rapper: Parsing file <stdin> with parser rdfxml and base URI file:
> rapper: Serializing with serializer ntriples and base URI file:
>
> <http://lcsh.info/sh85112589#concept>
> <http://www.w3.org/2004/02/skos/core#altLabel> "Humanities and
> religion"@en .
> <http://lcsh.info/sh85112589#concept>
> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
> <http://www.w3.org/2004/02/skos/core#Concept> .
> <http://lcsh.info/sh85112589#concept>
> <http://purl.org/dc/terms/created>
> "1986-02-11"^^<http://www.w3.org/2001/XMLSchema#date> .
> <http://lcsh.info/sh85112589#concept>
> <http://www.w3.org/2004/02/skos/core#prefLabel> "Religion and the
> humanities"@en .
> <http://lcsh.info/sh85112589#concept>
> <http://www.w3.org/2004/02/skos/core#broader>
> <http://lcsh.info/sh85062913#concept> .
> <http://lcsh.info/sh85112589#concept>
> <http://purl.org/dc/terms/modified>
> "1986-02-11T00:00:00"^^<http://www.w3.org/2001/XMLSchema#dateTime> .
> <http://lcsh.info/sh85112589#concept>
> <http://www.w3.org/2004/02/skos/core#inScheme> <http://lcsh.info/> .
> rapper: Parsing returned 7 triples
>
>
>
>
Received on Friday, 3 October 2008 09:23:30 GMT

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