RE: ISSUE-4: Versioning, namespace URIs and MIME types

On Tue, 17 Feb 2009, Larry Masinter wrote:
>
> If there were multiple languages which used the same namespace, (or 
> multiple versions, HTML 5 and HTML 6 or whatever) then 
> imp.createDocument needs to choose which language it is creating a 
> document *in*, no matter how that version is indicated in the 
> serialization.

DOM APIs do not have a concept of a pre-existing document. You can start 
from a DOMImplementation object and then create a Document without ever 
hitting the network or seeing any serialisation of any kind.


> > ...browsers are required, for compatibility with legacy content, 
> > XHTML1, DOM2 HTML, and DOM2 Core, to return an element that, when 
> > inserted into a document, displays either an image as indicated by its 
> > "src" attribute, or text as indicated by its "alt" attribute.
> 
> Legacy compatibility is one among several design goals which are often 
> traded off in the design process.

Keeping legacy compatibility is pretty much the number one requirement and 
design principle underpinning the HTML5 work. I don't think it's tradable.


> The existence of legacy table@summary attributes seems to have little 
> weight in the discussion, so the fact that there might be scripts which 
> would execute differently in HTML1 vs. XHTML2 or XHTML5 would need to be 
> evaluated using only the same criteria.

In fact, the main argument against keeping <table summary=""> is that 
legacy content has abused it so badly that it is unusable. So the argument 
is effectively the same one here.


> In http://lists.w3.org/Archives/Public/public-html/2008Aug/0765.html you 
> said "HTML5 started from a clean slate".
> 
> So what previous specifications say has not, apparently, been previously 
> upheld as an inviolate design principle.

Indeed, the spec is written with legacy content and implementations in 
mind, not previous specifications.

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

Received on Tuesday, 17 February 2009 22:47:53 UTC