Re: RDF document?

Hi Jeremy,
> It is a design issue. I would say that Literal is a medium to communicate 
> with the end-user. 
As your example with the hash-literal shows this is not necessarily the
case. Ideally the user should never have to type an URI, an application
could allow the user to drag-and-drop a bookmark into the foaf:homepage
field. Since the object is non-literal, the label of the bookmark can be
added as well
[] foaf:homepage <http://www.w3.org/> .
<http://www.w3.org/> dc:title "Leading the Web to Its Full
Potential...".

> [] foaf:homepage <http://www.w3.org/> .
> <http://www.w3.org/> foaf:sha1 
> "1480931ce0e2f1e89f05cf763390fbc57254724a"^^xsd:hexBinary .
> 
> If I treat the node <http://www.w3.org/> as if it is a blank node, it would 
> become..
> 
> [] foaf:homepage [ foaf:sha1 
> "1480931ce0e2f1e89f05cf763390fbc57254724a"^^xsd:hexBinary . ] .
> 
> Someone has a homepage that has a SHA1 sum 
> "1480931ce0e2f1e89f05cf763390fbc57254724a".
http://www.w3.org/ does not identify the same as
urn:hash::sha1:1480931ce0e2f1e89f05cf763390fbc57254724a because the
server can deliver different bytes depending e.g. on the Accept and
Accept-language header. In KnoBot[1] hash-uris are used to identify
concrete document variant, to see how they relate to web-resource you
can make a MGET request to the URL of an image which will return
something like this:

<rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:ns0="http://wymiwyg.org/ontologies/document#"
xmlns:ns1="http://wymiwyg.org/ontologies/rwcf#"
xmlns:ns2="http://purl.org/dc/elements/1.1/">
  <rdf:Description rdf:nodeID="X13Xb06041Xa3X1042c860cbeXa3X-2549">
    <ns2:language>fr</ns2:language>
    <rdf:type
rdf:resource="http://wymiwyg.org/ontologies/document#DocumentVariant"/>
    <ns0:content
rdf:resource="urn:hash::md5:a0ffa70b51f0a33b248759a168ad14cf"/>
    <ns0:contentType>image/jpeg</ns0:contentType>
  </rdf:Description>
  <rdf:Description
rdf:about="http://www.osar.ch/2005/03/23/sfh_sujet_4">
    <rdf:type
rdf:resource="http://wymiwyg.org/ontologies/document#Document"/>
    <rdf:type
rdf:resource="http://wymiwyg.org/ontologies/rwcf#AuthoritativelyServedResource"/>
    <ns0:variant rdf:nodeID="X13Xb06041Xa3X1042c860cbeXa3X-2416"/>
    <ns0:variant rdf:nodeID="X13Xb06041Xa3X1042c860cbeXa3X-2549"/>
  </rdf:Description>
  <rdf:Description rdf:nodeID="X13Xb06041Xa3X1042c860cbeXa3X-2416">
    <ns2:language>de</ns2:language>
    <rdf:type
rdf:resource="http://wymiwyg.org/ontologies/document#DocumentVariant"/>
    <ns0:content
rdf:resource="urn:hash::md5:96a7361f376e803c37269c6619779087"/>
    <ns0:contentType>image/jpeg</ns0:contentType>
  </rdf:Description>
</rdf:RDF>


cheers,
reto



1. http://wymiwyg.org/knobot

Received on Friday, 10 June 2005 14:04:31 UTC