[whatwg] RDFa

Ian Hickson ian at hixie.ch
Tue Sep 9 01:58:34 PDT 2008

On Mon, 8 Sep 2008, Elliotte Harold wrote:
> Henri Sivonen wrote:
> > 
> > The DOM consistency issue is that the xmlns attributes are DOM-wise 
> > different in text/html and application/xhtml+xml due to legacy 
> > reasons. The attribute that reads xmlns:cc="..." is represented 
> > differently in the DOM when the serialization was text/html than when 
> > it was application/xhtml+xml. We can't make xmlns:foo='...' conforming 
> > on HTML elements without either violating the DOM Consistency design 
> > principle (bad) or introducing namespace processing into HTML5 parsing 
> > (also bad).
> FWIW, I think introducing namespace processing into HTML 5 parsing is 
> the lesser evil here. I think it is substantially less bad than an 
> inconsistent DOM.

Both introducing a namespace prefix processing model and introducing DOM 
inconsistencies at the XML/HTML boundary intentionally are simply not an 
option in WHATWG specs at this point. Experience borne out of mechanisms 
that have had these characteristics [1] has shown these problems to be 
simply unacceptable for a Web authoring-level specification. This is 
feedback I have received from browser vendors and authors a lot.

([1] e.g. XML namespaces, which has the former characteristic when used in 
XHTML1 documents processed as XML and the latter characteristic when used 
in XHTML documents processed as HTML4.)

Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'

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