Re: list-expansion in RDFa

On a related note, having implemented parsers for RDF/XML and Notation-3 in addition to RDFa, I notice that RDFa is the only significant RDF serialization that does not make use of rdf:first/rdf:rest style list management. Turtle/N3 does this using the () notation, and RDF/XML through parseType ="Collection". Issue-16 (RDF Collections)<http://www.w3.org/2010/02/rdfa/track/issues/16> relates to this using the rdf:Seq/rdf:li generation (which I certainly prefer), but not the N3-style lists.

This could be accommodated by supporting something similar to parseType="Collection" on a <ol> element (or any element, really). Unfortunately, this would involve adding another attribute, which makes it problematic. However, the inability to reasonably serialize RDF lists in RDFa is a shortcoming.

Gregg

On Nov 10, 2009, at 5:59 PM, Gregg Kellogg wrote:

I notice that RDFa does not define rdf:li list expansion as in RDF/XML. In RDF/XML, according to http://www.w3.org/TR/rdf-syntax-grammar/#section-Syntax-list-elements, rdf:li is expanded to rdf:_1, rdf:_2 and so forth during expansion. I could not find anything similar in RDFa, but it seems like a reasonable operation.

An example test case could be the following:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML+RDFa 1.0//EN"
                      "http://www.w3.org/MarkUp/DTD/xhtml-rdfa-1.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <body>
    <ol about="http://example.com/9997.xhtml">
      <li property="rdf:li">This is first</li>
      <li property="rdf:li">This is second</li>
    </ol>
  </body>
</html>

With expected results:

<http://example.com/9997.xhtml> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_1> "This is first" . <http://example.com/9997.xhtml> <http://www.w3.org/1999/02/22-rdf-syntax-ns#_2> "This is second" .

Gregg

Received on Friday, 19 February 2010 20:16:28 UTC