Re: TWO Change proposals for ISSUE-41 : Distributed Extensibility

On Mar 16, 2010, at 11:34 PM, Leif Halvard Silli wrote:

> Maciej Stachowiak, Tue, 16 Mar 2010 22:15:16 -0700:
>
>> The former is essential, and separate
>> from any differences in processing that DOM. The latter will not be
>> achieved by Robert's proposal and is probably not practical for
>> various edge case reasons.
>
> Vendor prefixes would then be an edge case?
>
> What I meant was that if an attribute prefix lives in a namespaces
> according to one user agent, but not according to another (which could
> be a possibility in text/html, even if it may not be possible in
> XHTML), then a prefixed attribute "leave" on the DOM tree could be
> targeted, via CSS, like this,
>
> 	[*|attribute]{}
>
> in the UA that sees it as a namespace. And like this,
>
> 	[namespace\:attribute]{}
>
> in an UA which doesn't see the namespace.  May be this difference is
> what you refer to as the "produced DOM"? And I argue that one cannot
> avoid this difference, when it comes to vendor prefixes.

I could be misunderstanding, but my reading of Robert's Proposal X is  
that it would always place attributes in the namespace specified by  
the relevant xmlns declaration, regardless of whether the browser has  
special knowledge of a particular prefix. (Or if there is no namespace  
declaration in the document, the attribute would end up in the null  
namespace). Thus, which of the above selectors matches would be  
consistent in all browsers for any given document, assuming all  
browsers implement Proposal X.

>
> Effectively, in text/html, then a vendor specific namespace could be
> implemented without the use of a prefix - one could simply do this:
>
> 	<div -wexbkit="value">
>
> Those that support the -webkit namespace could then see it (in CSS) as
>
> 	[*|-webkit]
>
> Or as
>
> 	[webkitnamespace|-webkit]
>
> whereas the others could target it as
>
> 	[-webkit]

Robert's Proposal Y would not place prefixed attributes in a namespace  
(other than the null namespace). Thus, in all browsers, only an  
attribute selector with no prefix specified would match.


Regards,
Maciej