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Re: [RDFa] non-binding resolutions

From: Ivan Herman <ivan@w3.org>
Date: Tue, 31 Jul 2007 11:33:16 +0200
Message-ID: <46AF01DC.7050901@w3.org>
To: Ben Adida <ben@adida.net>
Cc: RDFa <public-rdf-in-xhtml-tf@w3.org>
Ben, looking at the rules again, and also considering the issue about
@about in, say:

http://www.w3.org/mid/46AA10E3.9020801@adida.net

I was wondering: why is @about in your rule set? If I look at your rules
for the "RDF Identity" (sorry Mark, I do not want to enter a
terminological debate here, but I want to have a clear reference to what
I refer to), I could simply say:

- the RDF identity of an HTML element is, in order of precedence
 	- @resource
 	- @href
 	- @src if it's an IMG
 	- a new bnode

ie, _no_ @about. All the examples you give below, as well as my rules
for collections/containers remain perfectly valid without it.

Well... of course the question is what the interpretation of this is:

<ul instanceof="rdf:Seq">
  <li about="#A">blabla <span property="p:q">bla2</span></li>
  <li href="#B">blabla <span property="p:q">bla3</span></li>
</ul>

But I could say this means:

<ul instanceof="rdf:Seq">
  <li property="rdf:_1" about="#A">
     blabla <span property="p:q">bla2</span></li>
  <li rel="rdf:_2" href="#B">
     blabla <span property="p:q">bla3</span></li>
</ul>

which yields

[ a rdf:Seq;
  rdf:_1 "blabla <span property="p:q">bla2</span>"^^XMLLiteral;
  rdf:_2 <#B>
]

which is consistent, though @about is useless, but that would be true
outside of containers as well.

Ie, the container/collection rule would say:

- In an <li> element
  - if @instanceof, @resource, or @href is present, add an @rel
  - otherwise add an @property

and then let the usual RDFa rules hold.

Ivan


Ben Adida wrote:
> 
> Hi all,
> 
> Mark, Ralph and I had a very productive chat today where we agreed on
> some non-binding resolutions. Our next steps are to
> 
> A) update the test cases
> B) update the implementations
> C) update the RDFa syntax doc (yes, we can start on this!)
> 
> 
> Why non-binding? Because we were only 3 on the call and the resolutions
> will be best achieved by *trying* them out in actual implementations,
> rather than theorizing on them endlessly.
> 
> So, here they are, your non-binding resolutions.
> 
> 1) @instanceof is the attribute name for rdf:type
> 
> 2) @id does *not* play a role in RDFa triple generation.
> 
> 3) @rel, @rev, and @instanceof cause chaining (aka striping), whether or
> not there is @href/@resource on the element.
> 
> 
> (2) and (3) cause changes to the rules I laid out a few days ago, so I
> will restate the rules completely now.
> 
> 
> - @rel (conversely @rev) creates triples with the given predicate. The
> object of @rel (conversely the subject of @rev) is the "RDF identity" of
> the current element, and the subject of contained elements is implicitly
> set to that same "RDF identity."
> 
> - @instanceof applies to the "RDF identity" of the current element, and
> sets of the subject of contained elements to this same "RDF identity."
> 
> - the RDF identity of an HTML element is, in order of precedence
> 	- @resource
> 	- @href
> 	- @src if it's an IMG
> 	- @about
> 	- a new bnode
> 
> (NOTE how @id is not present in this list anymore.)
> 
> Thus, here are some examples:
> 
> 
> 
> <div about="#me" rel="foaf:knows" instanceof="foaf:Person">
>   <span property="foaf:name">Mark</span>
> </div>
> 
> <#me> foaf:knows [ rdf:type foaf:Person ; foaf:name "Mark" ] .
> 
> 
> 
> 
> <div about="#me" rel="foaf:knows" instanceof="foaf:Person"
>      href="http://example.org/~mark">
>   <span property="foaf:name">Mark</span>
> </div>
> 
> <#me> foaf:knows <http://example.org/~mark> .
> <http://example.org/~mark>
>   rdf:type foaf:Person ;
>   foaf:name "Mark" .
> 
> 
> 
> 
> <div about="#me" instanceof="foaf:Person">
>   <span property="foaf:name">Ben</span>
> </div>
> 
> <#me> rdf:type foaf:Person .
>       foaf:name "Ben" .
> 
> 
> 
> 
> <div instanceof="foaf:Person">
>   <span property="foaf:name">Ben</span>
> </div>
> 
> _:div0 rdf:type foaf:Person ;
>        foaf:name "Ben" .
> 
> 
> 
> <img about="#me" rel="foaf:image" src="ben.jpg" />
> 
> <#me> foaf:image <ben.jpg> .
> 
> 
> 
> 
> And in any of these cases, adding @id doesn't change a thing about the
> RDFa triples generated.
> 
> -Ben
> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
PGP Key: http://www.ivan-herman.net/pgpkey.html
FOAF: http://www.ivan-herman.net/foaf.rdf


Received on Tuesday, 31 July 2007 09:33:21 GMT

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