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RE: [PROPOSAL] Named graphs in RDFa

From: Hausenblas, Michael <michael.hausenblas@joanneum.at>
Date: Wed, 19 Dec 2007 21:24:07 +0100
Message-ID: <768DACDC356ED04EA1F1130F97D2985201449CFD@RZJC2EX.jr1.local>
To: "Mark Birbeck" <mark.birbeck@x-port.net>
Cc: <public-rdf-in-xhtml-tf@w3.org>, "SWD WG" <public-swd-wg@w3.org>


Mark,

Thanks for your explanation - as always a pleasure to read.
If I understood correctly this is basically what I was looking for! :)

I therefore withdraw my original proposal and would like to suggest
that this aspect (or more precisely: your explanation of it ;)
somehow finds its way into the RDFa Syntax document.

Cheers,
	Michael

----------------------------------------------------------
 Michael Hausenblas, MSc.
 Institute of Information Systems & Information Management
 JOANNEUM RESEARCH Forschungsgesellschaft mbH
 Steyrergasse 17, A-8010 Graz, AUSTRIA
---------------------------------------------------------- 

> -----Original Message-----
> From: Mark Birbeck [mailto:mark.birbeck@x-port.net] 
> Sent: Wednesday, December 19, 2007 5:01 PM
> To: Hausenblas, Michael
> Cc: public-rdf-in-xhtml-tf@w3.org; SWD WG
> Subject: Re: [PROPOSAL] Named graphs in RDFa
> 
> Hi Michael,
> 
> This is an interesting problem, and one I've avoided 
> commenting on because it could take every waking minute of 
> the day. :) Anyway, all of the following is in the 
> 'theoretical' bin....
> 
> I think RDFa is unusual in that it doesn't have a named graph 
> problem in the way that, say, RDF/XML does, because the XHTML 
> document *is* the 'named graph'.
> 
> The interesting thing about an HTML/XHTML document is that 
> there is both a head and a body section of the document, 
> which means that we could define things in such a way that we 
> are making *two* lots of statements; one lot about the 
> document itself, and one lot about the 'content' referred to 
> by the document.
> 
> The document itself is a named graph, since it has a URL, and 
> contains metadata. Of course, normally all metadata in the 
> document is 'about'
> that document unless overridden by an @about, so to 
> distinguish between statements about the document (i.e., the 
> graph) and statements about some other things you'd always 
> have to add an @about.
> 
> However, if a typical document looked like this:
> 
>   <html>
>     <head about="">
>       ...statements about the named graph...
>     </head>
>     <body about="#">
>       ...statements about the content, e.g., my FOAF page...
>     </body>
>   </html>
> 
> you would effectively have a 'named graph', which is the 
> information resource at "", accompanied by a resource, 
> identified by "#"; note how this might also solve the 
> interminable information resource question.
> 
> (As it happens this trick of distinguishing between the 
> document carrying the metadata and what the metadata is about 
> could have been done with RDF/XML, but in RDF/XML if 
> @rdf:about is empty it means that statements are being made 
> about the current document; in short, there is no way to 
> distinguish between the document that contains the graph, and 
> the graph itself.
> 
> If we also added a statement that the 'primary topic' of the 
> named graph, was the resource identified in the body:
> 
>   <html>
>     <head about="">
>       <link rel="foaf:primaryTopic" href="#" />
>       ...statements about the named graph...
>     </head>
>     <body about="#">
>       ...statements about the content, e.g., my FOAF page...
>     </body>
>   </html>
> 
> then everything is complete; now, when someone links to the 'graph'
> from an HTML page (the most likely scenario), it is a simple 
> matter to sort out what exactly is being referred to.
> 
> Regards,
> 
> Mark
> 
> On 19/12/2007, Hausenblas, Michael 
> <michael.hausenblas@joanneum.at> wrote:
> >
> >
> > All,
> >
> > Proposal:
> > Add a mechanism to RDFa that allows to indicate a graph's 
> provenance 
> > (aka named graphs, etc.).
> >
> > In the first phase we should decide IF we want this (or not 
> :), then 
> > if/when we agree, we should discuss HOW to implement it.
> >
> > Rational:
> > Due to the ongoing discussions [1] and Fabien's W3C member 
> submission 
> > [2] is ask myself:
> > Why don't we introduce this feature in RDFa?
> >
> > As we are about (or partly already did) add new stuff 
> anyway (such as 
> > XHTML voc, CURIE, etc.), why not supporting this IMO very important 
> > feature right from the beginning?
> >
> > Any thoughts?
> >
> > Cheers,
> >         Michael
> >
> > [1] 
> http://lists.w3.org/Archives/Public/semantic-web/2007Dec/0035.html
> > [2] http://www.w3.org/Submission/rdfsource/
> >
> > ----------------------------------------------------------
> >  Michael Hausenblas, MSc.
> >  Institute of Information Systems & Information Management  
> JOANNEUM 
> > RESEARCH Forschungsgesellschaft mbH  Steyrergasse 17, A-8010 Graz, 
> > AUSTRIA
> >
> >  <office>
> >     phone: +43-316-876-1193 (fax:-1191)
> >    e-mail: michael.hausenblas@joanneum.at
> >       web: http://www.joanneum.at/iis/
> >
> >  <private>
> >    mobile: +43-660-7621761
> >       web: http://www.sw-app.org/
> > ----------------------------------------------------------
> >
> >
> 
> 
> --
>   Mark Birbeck, formsPlayer
> 
>   mark.birbeck@formsPlayer.com | +44 (0) 20 7689 9232
>   http://www.formsPlayer.com | http://internet-apps.blogspot.com
> 
>   standards. innovation.
> 
Received on Wednesday, 19 December 2007 20:24:26 GMT

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