W3C home > Mailing lists > Public > www-html@w3.org > June 2005

Re: DC in XHTML2

From: Phil Archer <parcher@icra.org>
Date: Wed, 8 Jun 2005 10:40:16 +0100
Message-ID: <004f01c56c0e$956c4590$63601052@PHILXP>
To: <semantic-web@w3.org>, <www-html@w3.org>, <iptc-metadata@yahoogroups.com>, <dc-general@jiscmail.ac.uk>

RE: DC in XHTML2Mark and all,

Can I offer another use case for being able to use Qnames as values of 
properties.

I've been working with several others on ways to make it easy to apply an 
RDF description to groups of resources rather than a single URI in a system 
we call RDF Content Labels [1]. One application of this is encoding film 
classifications.

If I understand the spec correctly, this is valid XHTML 2

<html xmlns="http://www.w3.org/2002/06/xhtml2/"
      xmlns:dc="http://purl.org/dc/elements/1.1/"
      xmlns:label="http://www.w3.org/2004/12/q/contentlabel">
<head>
  <title>Movies on demand</title>
  <link rel="label:hasDefaultClassification"
     href="http://www.classificationboard.nl/age#all" 
type="application/rdf+xml" />
  <link rel="meta" about="#titanic" 
href="http://www.classificationboard.nl/age#twelve"
     type="application/rdf+xml" />
  <link rel="meta" about="#usual" 
href="http://www.classificationboard.nl/age#eighteen"
    type="application/rdf+xml" />
</head>
<body>

<div id="teletubbies"> <!-- gets the default classification  set in head 
section -->
  <span property="dc:title" class="title">Teletubbies The Movie</span>
  <a href="teletubbies.mov>See the movie</a>
</div>

<div id="titanic">
  <span property="dc:title" class="title">Titanic</span>
  <a href="titanic.mov">See the movie</a>
</div>

<div id="usual">
  <span property="dc:title" class="title">The Usual Suspects</span>
  <a href="usual_suspects.mov">See the movie</a>
</div>

As Lisa pointed out, we can use Link/rel tags at the top if we want to give 
a URI as a property value. But, support for Qnames would make this a lot 
easier since, yes, it's more compact, and, no less important I'd say, it's 
more natural to add the metadata to the thing you're writing as you do it 
rather than having to go back and add the metadata to the head section as a 
separate operation/thought process.

<html xmlns="http://www.w3.org/2002/06/xhtml2/"
      xmlns:dc="http://purl.org/dc/elements/1.1/"
      xmlns:label="http://www.w3.org/2004/12/q/contentlabel"
      xmlns:age="http://www.classificationboard.nl/age#">
<head>
  <title>Movies on demand</title>
  <meta property="label:hasDefaultClassification" resource="age:all" />
</head>
<body>

<div id="teletubbies"> <!-- gets the default classification  set in head 
section -->
  <span property="dc:title" class="title">Teletubbies The Movie</span>
  <a href="teletubbies.mov>See the movie</a>
</div>

<div id="titanic" property="label:hasClassification" resource="age:twelve">
  <span property="dc:title" class="title">Titanic</span>
  <a href="titanic.mov">See the movie</a>
</div>

<div id="usual" property="label:hasClassification" resource="age:eighteen">
  <span property="dc:title" class="title">The Usual Suspects</span>
  <a href="usual_suspects.mov">See the movie</a>
</div>

[1] http://www.w3.org/2004/12/q/doc/rdf-contentlabels.html

Phil Archer



----- Original Message ----- 
From: Mark Birbeck
To: 'Misha Wolf'
Cc: www-rdf-interest@w3.org ; semantic-web@w3.org ; www-html@w3.org ; 
iptc-metadata@yahoogroups.com ; dc-general@jiscmail.ac.uk
Sent: Tuesday, June 07, 2005 11:16 PM
Subject: RE: DC in XHTML2


Hi Misha,
One way to achieve a more abbreviated mark-up, even if it is not the full 
solution of 'QNames in @href', is to use @xml:base. All @href values will be 
relative to this, and an RDF/A processor should honour changes of base URI 
through the mark-up. It will at least make your mark-up more compact.
That's not to say that we shouldn't try to find other solutions, too. In one 
of my early drafts of RDF/A I did actually have an additional attribute 
called @resource, which was a QName, and which sat alongside @href. See 
section 4.2 of RDF/XHTML, as it was then called:
  <http://www.formsplayer.com/notes/xhtml-meta-data-03.html>
There was some resistance to it, since some people rightly say that QNames 
are not URIs. But anyway, I'll take another look at it, since I certainly 
think that yours is a strong use case for something less that a full URI.
Regards,
Mark
PS Good to see you all at your AGM today, and even better to see that your 
requirements are being fed into the XHTML2 and RDF/A work!


Mark Birbeck
CEO
x-port.net Ltd.
e: Mark.Birbeck@x-port.net
t: +44 (0) 20 7689 9232
w: http://www.formsPlayer.com/
b: http://internet-apps.blogspot.com/
Download our XForms processor from
http://www.formsPlayer.com/
> -----Original Message----- 
> From: www-html-request@w3.org
> [mailto:www-html-request@w3.org] On Behalf Of Misha Wolf
> Sent: 07 June 2005 18:04
> To: dc-general@jiscmail.ac.uk
> Cc: www-rdf-interest@w3.org; semantic-web@w3.org;
> www-html@w3.org; iptc-metadata@yahoogroups.com
> Subject: DC in XHTML2
>
>
> As some of you will know, the XHTML2 draft [1] introduces a
> very interesting syntax for RDF, which many would consider to
> be an improvement on the traditional RDF/XML syntax.  No
> doubt, many content authors will be seeking to add DC
> metadata to their XHTML2 content using these new mechanisms.
>
> The News Architecture Working Party of the International
> Press Telecommunications Council (IPTC) is investigating the use of
> XHTML2 for expressing DC and other metadata.  A major problem
> for us is the lack of support in the current XHTML2 draft (as
> in RDF/XML) for the use of QNames to express terms in
> controlled vocabularies (aka values of properties).
>
> At the moment, the XHTML2 @content attribute takes PCDATA and
> the @href attribute takes IRIs.  There is no attribute
> available for QNames.
>
> We want to be able to use, eg, <dc:subject> with a QName as a
> value (ie the object of the RDF statement).  The reasons
> include legibility and compactness.  News items (and news
> headlines) often carry numerous subject codes, hence the need
> for compactness.
>
> Is anyone else in the DC community looking at the use of DC in
> XHTML2 and thinking along similar lines to us?  We would be
> very happy to work with others on this issue.
>
> [1] http://www.w3.org/TR/xhtml2
>
> Misha Wolf
> Standards Manager, Reuters
> Chair, News Metadata Framework WG, IPTC
> Vice-Chair, News Architecture WP, IPTC
>
>
>
>
> ----------------------------------------------------------------- 
>         Visit our Internet site at http://www.reuters.com
>
> To find out more about Reuters Products and Services visit
> http://www.reuters.com/productinfo
>
> Any views expressed in this message are those of  the
> individual sender,  except  where  the sender specifically
> states them to be the views of Reuters Ltd.
>
>
> 
Received on Wednesday, 8 June 2005 09:44:00 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 5 February 2014 07:19:03 UTC