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Re: RDFa and Web Directions North 2009

From: Ivan Herman <ivan@w3.org>
Date: Mon, 16 Feb 2009 11:21:24 +0100
Message-ID: <49993E24.1070404@w3.org>
To: Henri Sivonen <hsivonen@iki.fi>
CC: Mark Birbeck <mark.birbeck@webbackplane.com>, Sam Ruby <rubys@intertwingly.net>, Kingsley Idehen <kidehen@openlinksw.com>, Dan Brickley <danbri@danbri.org>, Michael Bolger <michael@michaelbolger.net>, public-rdfa@w3.org, RDFa mailing list <public-rdf-in-xhtml-tf@w3.org>, Tim Berners-Lee <timbl@w3.org>, Dan Connolly <connolly@w3.org>, Ian Hickson <ian@hixie.ch>


Henri Sivonen wrote:
> On Feb 16, 2009, at 11:20, Ivan Herman wrote:
> 
>> I would like to have one point of clarification, if I may...
>>
>> Henri Sivonen wrote:
>> [snip]
>>>
>>> This problem can be addressed by using absolute URIs instead of CURIEs
>>> and phasing out CURIEs by declaring xmlns:http="http:" on the XML side
>>> during the transition. (If that makes the predicates annoyingly long,
>>> what you have is a fundamental problem with the idea of using URIs as
>>> identifiers as opposed to using them for application-level addressing on
>>> the Internet. In that case, you should address that problem directly on
>>> the level of the RDF model instead of trying to push the annoyance
>>> around syntactically.)
>>>
>>> If you wish to get new features added to HTML5 and the proposed syntax
>>> depends on element or attribute names that contain the colon (xmlns:foo
>>> in this case), you are just asking for trouble because the colon is
>>> special in XML but not in text/html (and if you ask making it special in
>>> text/html, too, you are asking more than just adding a few attributes).
>>>
>>
>> Your approach is to phase out CURIE-s altogether on technical grounds.
>> However, isn't it correct that those issues disappear if the current
>> @xmlns:ABCD mechanism is exchanged against a @prefix="ABCD=blabla"
>> approach?
> 
> Yes, the DOM Consistency issue would disappear if, and only if, also the
> XHTML side used @prefix instead of @xmlns:ADCD.
>

Thank you. That what I thought.

> (It would leave the problem that prefix-based indirection in itself
> confuses people--sometimes in bug-inducing ways. See for example:
> http://lists.xml.org/archives/xml-dev/200502/msg00306.html
> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6475032
> http://dev.ctor.org/soap4r/ticket/179
> http://sourceforge.net/tracker/?func=detail&atid=454391&aid=924041&group_id=48863 
> )

Yes, I know that this issue was raised before (by you and maybe some
others in the list that I do not remember). But I just want to make it
clear that, technically speaking, completely phasing out CURIE-s is not
a _requirement_ to overcome the technical issues, because @prefix might
also do the trick.

Note that the RDFa group is looking at the issue of @prefix. Also, some
of the implementations (including software running the RDFa
distiller[1], though that is not a browser side tool) already implements
some form of @prefix, although not widely announced because there is no
agreement on the exact syntax yet.

Thanks

Ivan

[1]http://www.w3.org/2007/08/pyRdfa/


> 

-- 

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
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Received on Monday, 16 February 2009 10:22:11 GMT

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