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Re: Blank nodes & classes

From: Ben Adida <ben@adida.net>
Date: Wed, 13 Jun 2007 00:02:28 -0700
Message-ID: <466F9684.10202@adida.net>
To: CÚdric Mesnage <cedric.mesnage@lu.unisi.ch>
CC: public-rdf-in-xhtml-tf@w3.org


Cedric,

This is an interesting question. I had to deal with this with the RDFa
clipboard [1], and I chose to use the predicate rel="rdf:li" on any
bnode I wanted to appear on the page, effectively saying "this bnode is
an item of the current page." For example, in your code below:

<span class="foaf:Person" rel="rdf:li">
some things about the person
</span>

which yields:

<> rdf:li
     [a foaf:Person; ...things about the person...]

I'm pretty sure this is not a "best practice", but it's the work-around
I came up with for precisely this issue, and it's not all that wrong in
terms of semantics: after all, that *is* an item on the page.

-Ben

CÚdric Mesnage wrote:
> Hi all,
> 
> I have a question regarding blank nodes in RDFa, I don't know if the
> issue has been raised already and I apologize if it has. In the RDFa
> Primer I saw that you can create unnamed blank nodes using the 'rel'
> attribute as in the example:
> 
> <dl class="foaf:Person" about="#card" id="card">
> ...
>  <dt>Address</dt>
>  <dd rel="foaf:address">
>   <span property="foaf:address_line_1">77 Massachusetts Ave.</span><br />
>     <span property="foaf:address_line_2">MIT Room 32-G524</span><br />
>   <span property="foaf:city">Cambridge</span> MA 02139<br />
>   <span property="foaf:country">USA</span>
>  </dd>
> ...
> </dl>
> 
> This works for predicates layered in an instance definition, do you plan
> having a similar principle for classes? I'd like to have:
> 
> <span class="foaf:Person" >
> some things about the person
> </span>
> 
> to be considered as a blank node, currently in RDFa On
> Rails(http://rdfa.rubyforge.org/) I generate blank node names this way:
> 
> <span class="foaf:Person" about="#BNode1">
> some things about the person
> </span>
> 
> incrementing the number through the page generation, but this is ugly.
> The other solution is that I can just forbidden the use of classes if no
> uri or explicit blank node name is given.
> 
> Hope this does make some sense and look forward to get you point of view.
> 
> Best Regards!
> ---
> CÚdric Mesnage
> PhD Student
> cedric.mesnage@lu.unisi.ch <mailto:cedric.mesnage@lu.unisi.ch>
> http://www.inf.unisi.ch/phd/mesnage/
> http://myunderstanding.wordpress.com/
> 
> 
Received on Wednesday, 13 June 2007 07:02:33 UTC

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