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Re: Avoid setting href as new subject when no rel/rev is present

From: Ivan Herman <ivan@w3.org>
Date: Fri, 15 Jan 2010 09:53:15 +0100
Message-ID: <4B502CFB.4000703@w3.org>
To: Stephane Corlosquet <scorlosquet@gmail.com>
CC: RDFa mailing list <public-rdf-in-xhtml-tf@w3.org>
Hi Stéphane,

- The usage of @rel="" is technically correct in my reading of the spec
(and my distiller code:-): step 5 of the processing steps[1] is applied,
and that step only refers to the existence of @rel/@rev not whether they
provide valid URI-s.

- Whether it is good practice or not is of course another question. As
far as I am concerned, I think it is cleaner if, eg, an explicit @about
is placed there (as Toby proposed). This may be a bit of a pain for a
human author but it does not cost a penny, I presume, for an automatic
procedure in Drupal...

Cheers

Ivan


[1] http://www.w3.org/TR/2008/REC-rdfa-syntax-20081014/#s_model

On 2010-1-14 19:21 , Stephane Corlosquet wrote:
> Hi,
> 
> I just found a bug in the RDF output generated on Drupal 7 frontpage [1].
> This is the code of interest (cleaned up for clarity):
> 
> <div about="/node/12">
>   <ul>
>     <li>
>       <a content="4" property="sioc:num_replies" href="/node/12#comments">4
> comments</a>
>     </li>
>   </ul>
> </div>
> 
> I initially thought it would create the triple
> </node/12> sioc:num_replies "4" .
> but it turns out the RDFa parser I use generates
> </node/12#comments> sioc:num_replies "4" .
> 
> What's happening is that the href URI is set as new subject because there
> are no rel/rev (due to the parsing rule 4 at [2]). Adding rel="" does the
> trick and the Ubiquity-rdfa parser return the expected triple. Another
> option would be to repeat about="/node/12" in the a tag, though I like the
> empty rel better:
> 
> <div about="/node/12">
>   <ul>
>     <li>
>       <a content="4" property="sioc:num_replies" rel=""
> href="/node/12#comments">4 comments</a>
>     </li>
>   </ul>
> </div>
> 
> I just wanted to check and make sure there is not problem in using the empty
> rel hack, or whether there is a better way of working around this?
> 
> Steph.
> 
> [1] http://drupalrdf.openspring.net/
> [2] http://www.w3.org/TR/rdfa-syntax/#sec_5.5.
> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
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Received on Friday, 15 January 2010 08:52:28 UTC

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