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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 16:13:12 +0000
To: Dan Brickley <danbri@danbri.org>
CC: RDFa <public-rdf-in-xhtml-tf@w3.org>, "www-tag@w3.org WG" <www-tag@w3.org>, Ed Summers <ehs@pobox.com>
Message-ID: <233101CD2D78D64E8C6691E90030E5C81B6CFA8683@GVW1120EXC.americas.hpqcorp.net>

Hi Dan,

> Not sure what's up with wget, but curl seems to proke an rdf/xml response just fine.

Probably user error or proxy failre on my part, though I can't for the life of me see what I'm doing wrong. Transcript below, but happy to concede that it's my mistake.

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

skw@williams-s-2 ~/play
$ wget -d --header="Accept: application/rdf+xml" http://lcsh.info/sh85112589
Setting --header (header) to Accept: application/rdf+xml
DEBUG output created by Wget 1.11.3 on cygwin.

--2008-10-03 17:07:45--  http://lcsh.info/sh85112589
Connecting to proxy:8088... connected.
Created socket 3.
Releasing 0x006ab9f8 (new refcount 1).

---request begin---
GET http://lcsh.info/sh85112589 HTTP/1.0
User-Agent: Wget/1.11.3
Accept: application/rdf+xml
Host: lcsh.info

---request end---
Proxy request sent, awaiting response...
---response begin---
HTTP/1.1 200 OK
Date: Fri, 03 Oct 2008 16:07:01 GMT
Server: Apache/2.2.8 (Ubuntu) DAV/2 SVN/1.4.6 PHP/5.2.4-2ubuntu5.3 with Suhosin-Patch mod_wsgi/1.3 Python/2.5.2
Content-location: http://lcsh.info/sh85112589.html
Content-Type: application/xhtml+xml; charset=UTF-8
Content-length: 2720
Connection: close
Age: 139

---response end---
200 OK
Length: 2720 (2.7K) [application/xhtml+xml]
Saving to: `sh85112589.6'

100%[===============================================================================================================================================================>] 2,720       --.-K/s   in 0s

Closed fd 3
2008-10-03 17:07:45 (27.4 MB/s) - `sh85112589.6' saved [2720/2720]



> -----Original Message-----
> From: Dan Brickley [mailto:danbri@danbri.org]
> Sent: 03 October 2008 16:56
> To: Williams, Stuart (HP Labs, Bristol)
> Cc: RDFa; www-tag@w3.org WG; Ed Summers
> Subject: Re: lcsh.info RDFa SKOS and content negotiation -
> use of RDF-style # IDs in RDFa?
>
> Williams, Stuart (HP Labs, Bristol) wrote:
> > Hello Dan,
> >
> >> -----Original Message-----
> >> From: Dan Brickley [mailto:danbri@danbri.org]
> >> Sent: 03 October 2008 13:50
> >> To: Williams, Stuart (HP Labs, Bristol)
> >> Cc: RDFa; www-tag@w3.org WG; Ed Summers
> >> Subject: Re: lcsh.info RDFa SKOS and content negotiation -
> >> use of RDF-style # IDs in RDFa?
> >>
> >> Williams, Stuart (HP Labs, Bristol) wrote:
> >>> 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.
> >>
> >> This is a conneg case; there is RDF/XML and RDFa coming from
> >> the same URI.
> >
> > We could quibble (and I will:-) though it doesn't matter
> wrt to the main point at hand). A few wgets with and without
> accept header reveals that retrievals on
> http://lcsh.info/sh85112589 always (seems to) return an
> application/xhtml+xml representation.
>
> curl -H 'accept: application/rdf+xml' http://lcsh.info/sh85112589
> <?xml version="1.0" encoding="UTF-8"?>
> <rdf:RDF
>     xmlns:dcterms="http://purl.org/dc/terms/"
>     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
>     xmlns:skos="http://www.w3.org/2004/02/skos/core#"
>  >
>    <rdf:Description rdf:about="http://lcsh.info/sh85112589#concept">
>      <skos:broader
> rdf:resource="http://lcsh.info/sh85062913#concept"/>
>      <skos:inScheme rdf:resource="http://lcsh.info/"/>
>      <dcterms:modified
> rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">1986-
> 02-11T00:00:00</dcterms:modified>
>      <rdf:type
> rdf:resource="http://www.w3.org/2004/02/skos/core#Concept"/>
>      <skos:altLabel xml:lang="en">Humanities and
> religion</skos:altLabel>
>      <dcterms:created
> rdf:datatype="http://www.w3.org/2001/XMLSchema#date">1986-02-1
> 1</dcterms:created>
>      <skos:prefLabel xml:lang="en">Religion and the
> humanities</skos:prefLabel>
>    </rdf:Description>
> </rdf:RDF>
>
> Not sure what's up with wget, but curl seems to proke an rdf/xml
> response just fine. Other flavours are available, per
> http://lcsh.info/
> "The server uses content negotiation to determine what
> representation of
> the concept to send: application/rdf+xml, text/n3,
> application/json, and
> otherwise application/xhtml+xml."
>
> Am I misunderstanding what you're trying to do with wget?
>
> (re content-location headers -- quite possibly there are issues with
> those, I've not looked at them closely, but it does seem to send
> "Content-location: http://lcsh.info/sh85112589.rdf" ok with
> the rdf/xml
> above)
>
> >>> 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 you've found the best way of wriggling through this mess of
> >> specs :) It doesn't feel entirely graceful but it should at
> >> least allow
> >> us to deploy RDF/XML and RDFa alongside each other in this style.
> >>
> >>> I think that the relevant media-type registrations could
> >> (and probably should) be brought into line.
> >>
> >> That would be nice. Is it feasible?
> >
> > I would have thought it possible. Lurking somewhere in the
> background once upon a time was an intention to update RFC
> 3023 (the XML media-type registration) which I'm trying to
> find out status on. Coordinating updates to that and to any
> +xml media type registrations that build on its defaults
> would be essential I would have thought. Updating the
> application/xhtml+xml media type registration seems to me to
> fall within the scope of the XHTML2 WG and... (taking a deep
> breath)... the relationship between XHTML (of any flavor) and
> the text/html media type is entirely mysterious to me (eg.
> XHTML+RDFa served up as "text/html"... could/should that happen?).
> >
> >> I was wondering whether we might also sneak in a common symbol
> >> '#123412341234' (or something else obscure) meaning "the main thing
> >> described by this document", so that this common case could proceed
> >> without risk of unintended clashes (except by those who use that
> >> hard-to-guess symbol).
> >
> > I have a horrible feeling that that's a serious suggestion!
>
> Uglier things have gotten through ;)
>
> > I'd prefer tdb:2008:http://lcsh.info/sh85112589 (modulo
> syntax), with Larry Masinter's tdb: scheme taken through the
> URI scheme registration process, which is only a stones throw
> away from Steven's pto: idea. And... lest I forget,
> http://t-d-b.org/?http://lcsh.info/sh85112589 would also do
> the trick (modulo being temporally grounded).
>
> Yeah, I like tdb: ...
>
> cheers,
>
> Dan
>
> --
> http://danbri.org/
>
Received on Friday, 3 October 2008 16:16:16 GMT

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