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Re: RDDL->RDF (was Re: Draft agenda of 22 February 2005 TAG

From: Dan Connolly <connolly@w3.org>
Date: Wed, 23 Feb 2005 09:13:43 -0600
To: "Henry S. Thompson" <ht@inf.ed.ac.uk>
Cc: www-tag@w3.org
Message-Id: <1109171624.4991.1066.camel@localhost>

On Wed, 2005-02-23 at 08:55 +0000, Henry S. Thompson wrote:
[...]
>   For example,
> 
>   http://www.w3.org/2001/XMLSchema.html.

Hmm... OK... I get the following statements
(converted to turtle syntax
http://www.ilrt.bris.ac.uk/discovery/2004/01/turtle/
for clarity)


     @prefix : <#> .
     @prefix ns1: <http://www.rddl.org/purposes#> .

    :DTD     a
<http://www.isi.edu/in-notes/iana/assignments/media-types/application/xml-dtd>;
         ns1:validation <XMLSchema.dtd> .

    :xmlschema     a <http://www.w3.org/2001/XMLSchema>;
         ns1:schema-validation <XMLSchema.xsd> .

    :xmlschemap1     a <http://www.w3.org/TR/html4>;
         ns1:normative-reference
<http://www.w3.org/TR/2004/PER-xmlschema-1-20040318/> .



(a) why are the subjects of these statements different?
They should have a common subject, right?
Does XLink say what URI is the other end of the link
in these cases? the XLink terminology seems to
be 'starting resource'...

Hmm...
 [Definition: A local resource is an XML element that participates in a
link by virtue of having as its parent, or being itself, a linking
element].

that makes it sound like link resources are syntactic
elements. I would have thought that the subject
(aka starting resource?) in this case is the XML Schema
namespace. The RDDL spec talks about "related resource"s.
Related _to what_?


(b) using an IANA media-types registry entry as an RDF Class...
hmm... I wonder if IANA means it to be a class. Perhaps
better to use rddl:nature as the predicate there rather
than rdf:type.


Trying it on http://www.rddl.org/ itself, I see those
issues plus a syntax error...

  <rdf:Description rdf:about="http://www.rddl.org/#related.resources">

    <rdf:type rdf:resource="http://www.w3.org/1999/XSL/Transform" />
    <rdf:resource rdf:resource="rddl2rdf.xsl" />
  </rdf:Description>


Using rdf:resource as a property element isn't allowed.
http://www.w3.org/TR/rdf-syntax-grammar/#propertyElementURIs

I haven't figured out whether that problem comes from
the input or the transformation.

There also seem to be some (documented) limitations in handling
of URI references...

<!-- 
	note: assume xlink:arcrole := absoluteURI  '#' fragment-id
-->


p.s.

> Dan Connolly <connolly@w3.org> writes:
> 
> > On Tue, 2005-02-22 at 17:17 +0000, Henry S. Thompson wrote:
> >> Further to Item 1.1.3: Review action items 7 Feb [1]:
> >> 
> >>   ACTION: Henry to produce a RDDL1 to RDF Style sheet or explain why not
> >> 
> >> I find that Jonathan Borden produced such a stylesheet over four years
> >> ago [2].  I tried it, it seems to work.
> >
> > I'm curious... tried it with what? I forget which input syntax it
> > expects. I'll try to get swapped back in, but any help you can provide
> > is welcome.
> 
> Any RDDL document.

Ummm... the TAG has looked at a number of RDDL designs.
The "current" one, by some measure of current, is
  http://www.tbray.org/tag/rddl4.html
and given that document as input, [2] doesn't work; it gives...

<?xml version="1.0"?>
<!--RDF generated from RDDL document (http://www.rddl.org/-->
<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:rddl="http://www.rddl.org/"
xmlns:xlink="http://www.w3.org/1999/xlink"/>

So please disambiguate the term 'RDDL' more clearly, at
least for a little while.

-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E
Received on Wednesday, 23 February 2005 15:13:45 GMT

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