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Re: RDFa Profiles, terms, and predicates (oh my!)

From: Shane McCarron <shane@aptest.com>
Date: Thu, 22 Jul 2010 16:28:28 -0500
Message-ID: <4C48B7FC.4050302@aptest.com>
To: RDFa WG <public-rdfa-wg@w3.org>
Quick follow-up.  When using the predicate 'rdfa:uri', the object 
literal needs to be a URI.  Presumably it can be a relative URI:

    <p id='myTerm' about="#myTerm"><span property='rdfa:uri'
    content='#myTerm'><span property='rdfa:term'>myTerm</span></span></p>

If not... we should really say so.  If so.... we should probably say 
that too. And make it clear what the relative URI is resolved against 
(current base?).


On 7/22/2010 4:02 PM, Shane McCarron wrote:
> I was working on my (implied) action item to update our vocabulary 
> document so that it is an RDFa Profile, and I ran into something odd.  
> The rules for an RDFa Profile are pretty simple [1].  Shoehorning the 
> required predicates into our existing pattern in the vocab document is 
> a little daunting though.  I don't want to break what is already there 
> (in case someone is depending upon it)... Here is that pattern:
>
> <dt id="alternate" about="#alternate" 
> typeof="rdf:Property">alternate</dt>
> <dd about="#alternate" property="rdfs:comment"
>           datatype="xsd:string"><span>alternate</span>  designates 
> alternate
>           versions for a resource.</dd>
>
>
> Each term is defined that way.  All of our terms are defined within a 
> containing bucket like this:
>
> <div id="relrev-properties" about="#relrev-properties" typeof="rdf:Bag">
>
> <div about="#relrev-properties" rev="rdfs:member">
>
> Anyway.... our rules [1] require that in order for a term to be 
> defined, it must be the common subject of two predicates; rdfa:term 
> and rdfa:uri.  I completely understand why this is an attractive 
> general case model.  I can map ANY term to ANY URI.  However, in 
> reality, I expect that most vocabularies will be like ours - 
> self-contained.  In other words the vocabulary document will define 
> the term, and the URI for the term will be within that same document.  
> In the case above, for example, the URI for the term 'alternate' is 
> http://www.w3.org/1999/xhtml/vocab#alternate.
>
> With all this in mind, and in the spirit of never duplicating data 
> needlessly in an RDFa document, I propose that we modify the RDFa 
> Profile rules slightly.  That we say a term is defined by an 
> 'rdfa:term' predicate.  That the term itself is the object of that 
> predicate, and the URI is the object of an 'rdfa:uri' predicate on the 
> same subject if one is provided.  Otherwise, the URI is the same as 
> the subject of that predicate.
>
> Questions?  Comments?
>
> [1] http://www.w3.org/TR/rdfa-core/#s_profiles
>

-- 
Shane P. McCarron                          Phone: +1 763 786-8160 x120
Managing Director                            Fax: +1 763 786-8180
ApTest Minnesota                            Inet: shane@aptest.com
Received on Thursday, 22 July 2010 21:29:04 GMT

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