W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > July 2007

Re: Determination of subjects/objects

From: Ivan Herman <ivan@w3.org>
Date: Fri, 20 Jul 2007 17:16:21 +0200
Message-ID: <46A0D1C5.5070207@w3.org>
To: Ben Adida <ben@adida.net>
CC: W3C RDFa task force <public-rdf-in-xhtml-tf@w3.org>
O.k. I accept...

Ivan

P.S. As I said, I suspected that was the case, but if we already started
writing things down in a precise manner, it is good to have that
documented again:-)

Ben Adida wrote:
> Ivan,
> 
>> Niklas has already touched upon the problem of @id, and I was also a bit
>> surprised to see it in the list.
> 
> The treatment of @id has not changed recently :) As you suggest, by
> itself it doesn't do anything: you need @rel or @instanceof to have it
> do something. Consider the following driving use case:
> 
> <div id="me" instanceof="foaf:Person">
> ..
> </div>
> 
> Now if you have just:
> 
> <div id="me">
> 
> then that doesn't trigger anything, not even a subject for the contained
> elements, as that is just HTML without RDFa.
> 
> So when you say:
> 
>> However... I presume it is true that a change in the current 'RDF
>> identity' as an effect of an @id happens _only if there is an RDFa
>> related attribute on that element_, ie, if there is an @rel, @property,
>> etc, around. Other than that, the current RDF identity remains intact
>> while going down the XML tree. Is that so? If yes, than an @id appearing
>> on one of the elements in the tree may not have any effect. Is that
>> correct? With that additional rule, the usage of @id may not be that
>> dangerous after all.
> 
> you're exactly right.
> 
>> Having said that, I wonder whether it is not simpler to remove @id from
>> that algorithm altogether. It may be a little bit more convoluted for
>> the user but certainly safer.
> 
> I think some use cases become very clunky, then. Let's say you want to
> say you created the page. I'd like to write:
> 
> <div id="me" rel="dc:creator">
> 
> You'd have to write
> 
> <div id="me" rel="dc:creator" href="#me">
> 
> Is that really necessary?
> 
> I think the rule of @id being used when RDFa is invoked makes sense. On
> its own, it doesn't trigger anything.
> 
> -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 Friday, 20 July 2007 15:16:26 GMT

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