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RE: CURIEs, xmlns and bandwidth

From: Misha Wolf <Misha.Wolf@reuters.com>
Date: Fri, 28 Oct 2005 17:08:24 +0100
To: Dan Connolly <connolly@w3.org>
Cc: public-rdf-in-xhtml-tf@w3.org, public-swbp-wg@w3.org
Message-id: <A29ADE959C70A1449470AA9A212F5D80844795@LONSMSXM06.emea.ime.reuters.com>

Hi Dan,

We fully intend to use GRDDL to convert the metadata in News Items 
to triples.  We've decided to use URIs (expressed as CURIEs) for 
*every* term drawn from a vocabulary.  As any individual News Item 
will employ many vocabularies, this will require many prefix->URI 
declarations.  And we can't afford the impact of using xmlns for 
this purpose.  Consider a broadcast stream of real-time headlines.
Let's say that the text of each headline requires 50 bytes.  Let's 
also say that the story metadata (which needs to be carried with 
the headline to allow filtering by recipients) requires 20 
vocabularies and that each prefix declaration takes 50 bytes.  So 
having started with 50 bytes of text, we now end up broadcasting 
21 * 50 bytes.  This is why we want to use XInclude to allow the 
prefix->URI declarations to be outside the headline object.  And 
XInclude can't be used for xmlns declarations.

Misha Wolf
News Standards Manager, Reuters, www.reuters.com
Vice-Chair, News Architecture Working Party, IPTC, www.iptc.org/dev


-----Original Message-----
From: Dan Connolly [mailto:connolly@w3.org] 
Sent: 28 October 2005 16:48
To: Misha Wolf
Cc: public-rdf-in-xhtml-tf@w3.org; public-swbp-wg@w3.org
Subject: RE: CURIEs, xmlns and bandwidth

On Fri, 2005-10-28 at 14:51 +0100, Misha Wolf wrote:
> Hi all,
>  
> We've had confirmation that xmlns declarations can't be XIncluded.
> As a consequence, the IPTC does not plan to go the xmlns route for 
> declaring CURIEs.  If XHTML does decide to use xmlns for CURIE 
> declarations, that leaves us with two options:
>  
> 1.  Different standards use different declaration mechanisms.
>  
> 2.  The IPTC calls it's CURIEs by some other name.
>  
> Any comments?

I have lost track of many of the relevant constraints and requirements,
but have you considered a sort of microformat approach, using GRDDL?
i.e.

 start with XHTML 1.x
 choose a profile URI; put it in the head of each of your documents
 at that profile URI, add a profileTransformation link to 
  a bit of XSLT that expands your compact syntax to full RDF/XML

By way of precedent, let's look at "Embedded RDF"...

Here's an example document
  http://research.talis.com/2005/erdf/foaf-in-html.html

it uses an XHTML dialect for data that Ian Davis designed.

At the top, it declares that dialect/profile:
  <head profile="http://purl.org/NET/erdf/profile">

If we go to that profile document, we see it has
RDF embedded in such a way as to declare a transformation
of all documents that use this profile...
  <head profile="http://www.w3.org/2003/g/data-view">
...
     <link rel="transformation"
       href="http://www.w3.org/2003/g/glean-profile" />
...
  <a
        rel="profileTransformation"
 
href="http://purl.org/NET/erdf/extract-rdf.xsl">extract-rdf.xsl</a>

The net result is that we can take foaf-in-html.html and
put it into a GRDDL client (e.g. the online GRDDL service
http://www.w3.org/2003/11/rdf-in-xhtml-demo )
and out comes the data from the page in RDF/XML...

...
   <rdf:Description
rdf:about="http://research.talis.com/2005/erdf/foaf-in-html.html#ian">
       <name xmlns="http://xmlns.com/foaf/0.1/">Ian Davis</name>
       <firstName xmlns="http://xmlns.com/foaf/0.1/">Ian</firstName>
       <surname xmlns="http://xmlns.com/foaf/0.1/">Davis</surname>
...


-- 
Dan Connolly, W3C http://www.w3.org/People/Connolly/
D3C2 887B 0F92 6005 C541  0875 0F91 96DE 6E52 C29E



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Received on Friday, 28 October 2005 16:08:19 GMT

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