Re: RDFa test suite addition

On 29 Jul 2008, at 18:32, Shane McCarron wrote:

> I get what you are saying here... but you scared me with  
> something.  What is Cognition learning about a "namespace" in the  
> context of RDFa?  It should not be learning anything?  There are no  
> namespaces in RDFa.  There are prefix values and suffixes.  And the  
> concatenation of these creates URIs (IRIs) that, when dereferenced,  
> could mean something.  In my opinion Cognition could be learning  
> about those URIs... but the prefix value is meaningless.  Hell, the  
> prefix value could be "http".  It could be "h".  It would be  
> completely legitimate.


As I said, it's not so much a problem with the RDFa parsing, but any  
subsequent RDF/XML output.

Say, for example, we have the following RDFa:

     <div xmlns:ex="http://example.org/ns/" rel="ex:../foo"
     about="http://example.com/">
       Foobar
     </div>

This will be parsed as the following triple:

     <http://example.com/>
       <http://example.org/foo>
         "Foobar".

If the parser then is to output to RDF/XML, the result will be  
something like:

     <rdf:Description
         rdf:about="http://example.com/"
         XXX:YYY="Foobar"
     />

But won't know what to choose for 'XXX' or 'YYY'. I suppose it could  
figure out YYY by finding the last slash or hash sign in the  
predicate, then choose a random string to use for the prefix XXX, but  
the results are unlikely to be pretty.

-- 
Toby A Inkster
<mailto:mail@tobyinkster.co.uk>
<http://tobyinkster.co.uk>

Received on Tuesday, 29 July 2008 20:05:23 UTC