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Re: Henri's RDFa statements in the XHTML2 FAQ

From: Sam Ruby <rubys@intertwingly.net>
Date: Tue, 07 Jul 2009 13:34:03 -0400
Message-ID: <4A53870B.70608@intertwingly.net>
To: Manu Sporny <msporny@digitalbazaar.com>
CC: RDFa Developers <public-rdf-in-xhtml-tf@w3.org>
Manu Sporny wrote:
> Just throwing this out there in case some of you haven't seen it yet:
> 
> http://hsivonen.iki.fi/xhtml2-html5-q-and-a/
> 
> In it, Henri makes the following assertions:
> 
>> What happens to RDFa?
>>     RDFa (in XHTML but not in HTML!) is a W3C Recommendation and, as
>> such, doesnít need any terminating action per the W3C Process. Itís
>> unclear if another WG will develop further RDFa specs.
> 
> We will be developing further RDFa specs - whether it happens inside the
> W3C or outside the W3C is still up in the air.

I hope that this work can be done inside of the W3C.  If there is 
anything I can do to help, let me know.

>> Do semantics round-trip in an HTML5 to XHTML5 to HTML5 conversion?
>>    Yes, provided that the first HTML5 input is valid and you donít
>> ascribe semantics to characters that arenít allowed in XML (such as
>> form feed or U+FFFF). Note that RDFa isnít valid in either HTML5 or
>> XHTML5 as currently drafted.
> 
> We are certainly addressing all of the issues raised during the past
> several months[1]. Henri failed to mention that this work continues and
> that we are making progress.

I look forward to the time when this work results in a draft 
specification for RDFa in HTML.  I will note that the W3C Process 
Document states "Consensus is not a prerequisite for approval to 
publish; the Working Group MAY request publication of a Working Draft 
even if it is unstable and does not meet all Working Group requirements.".

I will also note that Henri's assertion about RDFa not being valid also 
applies to ARIA, despite the fact that his conformance checker has 
recognized ARIA for quite some time.

>> What about XHTML5 to HTML5 to XHTML5?
>>    Not if namespace-based extensibility is used. However, in the
>> common case, the conversion chain does round trip if the input is
>> valid XHTML5 + SVG 1.1 + MathML 2.0 (this excludes RDFa), doesnít use
>> namespaces from outside those specs (Itís debatable if the previous
>> condition already covers this.), xml:space on HTML elements is not
>> considered to affect semantics and relative URLs are rewritten so that
>> xml:base attributes can be removed without breaking links. (Answer
>> clarified/corrected 2009-07-07.)
> 
> My understanding is that XHTML5 and SVG 1.1 contain namespace support -
> so why is RDFa excluded from those languages on the basis of using
> namespaces and CURIEs in attributes (other than Henri's personal
> preferences)?

The current HTML5 draft special cases the SVG and MathML namespaces.

>> Are the semantics of HTML5 extensible?
>>    Yes. With microdata.
> 
> It's difficult to believe that WHATWG doesn't have a bias (as Ian has
> asserted repeatedly) when Microdata is being proposed as a solution.
> Microdata clearly does not have a test suite, does not have a set of
> implementations, and does not have much in the way of implementation
> feedback. RDFa has all of those in spades, but gets absolutely no
> mention as an alternative approach.
> 
> Henri's "FAQ" attempts to assert that RDFa is, and will continue to be,
> an incompatible technology with HTML5 and XHTML5. This couldn't be
> further from the truth. There will be an HTML+RDFa specification and
> there will be implementations (and, yes, that includes HTML5 and
> XHTML5). Whether WHATWG chooses to include it in their standard is what
> Henri is asserting as not happening. On that point, only time will
> tell... however, RDFa is out there in the wild now and it works. We'll
> ensure that it works in HTML5/XHTML5 as well.

What is currently in the HTML 5 draft has not yet been found to enjoy 
consensus.  I encourage people to work with the editor to get changes 
that they feel necessary made to this draft.  As an alternative, I 
encourage people to produce drafts, possibly including as much or as 
little of the current draft and submit them for consideration.

If you need access to the cvs repository for the HTML Working Group, 
please contact Mike Smith for access, and provide him with your ssh key. 
  It is my understanding that Rob Sayre and Steve Faulkner have already 
done so.

> -- manu
> 
> [1]http://rdfa.info/wiki/rdfa-in-html-issues#RDFa_Task_Force_Discussion_Order

- Sam Ruby
Received on Tuesday, 7 July 2009 17:34:45 GMT

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