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Re: Request to publish HTML+RDFa (draft 3) as FPWD

From: Shane McCarron <shane@aptest.com>
Date: Mon, 21 Sep 2009 23:00:46 -0500
Message-ID: <4AB84BEE.9030604@aptest.com>
To: Jonas Sicking <jonas@sicking.cc>
CC: Maciej Stachowiak <mjs@apple.com>, Manu Sporny <msporny@digitalbazaar.com>, HTMLWG WG <public-html@w3.org>, RDFa mailing list <public-rdf-in-xhtml-tf@w3.org>


Jonas Sicking wrote:
>>
>> Sure.  The rules for processing a source document are defined in the context
>> of the host language. In this case, the HTML 5 specification indicates the
>> rules for munging the input (I suppose).  RDFa doesn't care what the host
>> language does with valid input (I am assuming the above is valid HTML5).
>>  See the normative section 2 and informative seciton 2.1 of Manu's draft at
>> http://html5.digitalbazaar.com/specs/rdfa.html
>>     
>
> But neither the HTML5 specification, nor Manu's draft, define a prefix
> mapping algorithm for HTML documents. As far as I can see. I certainly
> agree that one of those two needs to be the defining specification.
>
>   

Manu's draft refers to the RDFa Syntax Recommendation.  The RDFa Syntax 
Recommendation normatively refers to the *syntax* of the Namespaces in 
XML Recommendation.  That syntax defines the eBNF for prefix 
declarations.  The RDFa Syntax Recommendation, in section 5.5, defines 
the way in which RDFa Processors are required to handle the hierarchy of 
prefix mappings.  I hope that this is clear from the specs.  If it is 
not, please help us by identifying somewhere there is a conflicting 
connection between these specifications.
> ....
>   
> I certainly agree that it's pathological, but I do still think it
> needs to be defined as when someone implements this they need to do
> *something*.
>
> However the more important question was if attributes in the null
> namespace can have any affect on RDFa processing. You seem to indicate
> that being the case. I'm curious if you're basing that on a
> specification, or if that's just how you think things *should* be
> defined?
>   

The later, I suppose.  The RDFa Syntax Recommendation defines the way in 
which source documents are mapped to triples.  There is *no* syntactic 
way to define two attributes with the same lexical name on the same 
element.  You have posited a non-source way to manipulate the DOM so 
that there is an attribute in the XMLNS namespace and an attribute in 
the null namespace that have the same lexical "name".  I agree that it 
is possible to manipulate the tree so that such a thing could happen.  
It is outside the scope of the RDFa Syntax Recommendation. I actually, 
personally, think it is academic and should be labeled "unspecified" if 
it is labeled at all.  But, since you asked, I suggested a way to handle 
the situation were it to occur on a given element.  I would be equally a 
happy to say "this is unspecified - it's a bad idea - don't do it... 
ever". Let me know which solution would best satisfy your concern.

-- 
Shane P. McCarron                          Phone: +1 763 786-8160 x120
Managing Director                            Fax: +1 763 786-8180
ApTest Minnesota                            Inet: shane@aptest.com
Received on Tuesday, 22 September 2009 04:03:40 GMT

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