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Re: ISSUE-120: Ambiguous Situation with nested @rel where inner @rel is neither CURIE nor link type

From: Ivan Herman <ivan@w3.org>
Date: Fri, 09 May 2008 06:50:48 +0200
Message-ID: <4823D828.5020105@w3.org>
To: public-rdf-in-xhtml-tf@w3.org
Hi Ben,

to be ruthlessly precise, the situation is not ambiguous; as you say, 
the spec leads to

<> dc:creator <ben.jpg>.

(this is also what my implementation does:-)

What I am afraid of is that a reformulation of the processing steps 
and/or the rest of the document might be too complicated to make the 
change worth. The way the document handles the content of @rel/@rev in 
such 'illegal' cases is a little bit convoluted in the sense that it 
tries to avoid some questions around interpretation of CURIE-s (@rel 
values are turned into URI-s, if possible, before anything else). All 
that should be changed to handle this situation the way you describe... 
And this may have unwanted consequences elsewhere.

I am not saying it is impossible, I am saying it may not be worth it...

Just my to cents

Ivan



SWD Issue Tracker wrote:
> ISSUE-120: Ambiguous Situation with nested @rel where inner @rel is neither CURIE nor link type
> 
> http://www.w3.org/2006/07/SWD/track/issues/120
> 
> Raised by: Ben Adida
> On product: RDFa
> 
> As per Ben's email [1]
> 
> """
> Here's the markup that we believe is ambiguous:
> 
> <div about="" rel="dc:creator">
>     <img rel="myfoobarrel" href="ben.jpg" />
> </div>
> 
> The question here is: does <ben.jpg> complete dc:creator, because 
> myfoobarrel is neither a CURIE nor a link type? In other words, do we 
> get the following triple:
> 
>    <> dc:creator <ben.jpg> .
> 
> ?
> 
> My interpretation of the spec is that rel="myfoobarrel" is completely 
> ignored, meaning that the triple completion behaves as if there was no 
> @rel on the img, which means that <ben.jpg> indeed completes dc:creator. 
> And I think that's a bad outcome.
> 
> Instead, I think the *presence* of @rel, no matter what it contains, 
> should cause completion of the incomplete triples. Then, once the 
> triples are completed, the *contents* of the @rel are considered for new 
> triple creation.
> 
> Consider what would happen if you had a different @rel:
> 
> <div about="" rel="dc:creator">
>     <img rel="foaf:img" href="ben.jpg" />
> </div>
> 
> which would then yield:
> 
>    <> dc:creator _:bnode1 .
>    _:bnode1 foaf:img <ben.jpg> .
> 
> Changing the @rel value on img should certainly kill the second triple, 
> but I don't see why it should change the first triple at all.
> 
> """
> 
> 
> [1] http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2008May/0045.html
> 
> 
> 

-- 

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 Friday, 9 May 2008 04:51:12 GMT

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