W3C home > Mailing lists > Public > public-html@w3.org > October 2009

Re: ISSUE-41/ACTION-97 decentralized-extensibility

From: Philip Taylor <pjt47@cam.ac.uk>
Date: Thu, 01 Oct 2009 22:47:26 +0100
Message-ID: <4AC5236E.10502@cam.ac.uk>
To: Maciej Stachowiak <mjs@apple.com>
CC: Adrian Bateman <adrianba@microsoft.com>, HTML WG <public-html@w3.org>, Tony Ross <tross@microsoft.com>, Sam Ruby <rubys@intertwingly.net>
Maciej Stachowiak wrote:
> 
> On Oct 1, 2009, at 1:22 PM, Adrian Bateman wrote:
> 
>> The key differences:
>>
>> * We don't support nested namespace declarations where one should 
>> override another
>> * We don't support the namespaces on attributes
>> * We only allow prefix declarations on the root element
> 
> Here's a few more differences; I suspect more would be found with deeper 
> study:
> 
> * In IE the localName, prefix and namespaceURI attributes whose values 
> are given by the proposal are entirely missing.
> * In IE, a tagUrn attribute that's not in the proposal is present, 
> holding the namespace URI.
> * in IE, the nodeName attribute value does not match what is proposed.
> * IE will not treat elements with localNames that match an existing HTML 
> element as the relevant HTML element, even if it has a namespace prefix 
> - the proposal does not include that behavior.

* IE has Element.scopeName
* IE has document.namespaces
* IE can bind prefixes with <xml:namespace prefix="v" /> and 
<?xml:namespace prefix="v" />
* document.write('<foo:bar>') will implicitly bind the foo prefix
* 'namespaced' elements with trailing slashes are parsed as empty elements.
* CSS selectors match on the full attribute name. (That means
     <html xmlns:foo>
     <style>foo\:bar { color: green }</style>
     <body><foo:bar>test</foo:bar>
will match in all current browsers, but it would break under the 
proposal (unless CSS was changed).)

These issues have been discussed several times before, e.g. in 
http://lists.w3.org/Archives/Public/public-html/2007Aug/thread.html#msg134

There's some examples at 
http://philip.html5.org/demos/html/ie-xmlns/vml.html of IE's parsing and 
processing.

> Example: do we know how common it is for current text/html content to 
> have a namespace declaration somewhere other than the root element? All 
> such content would behave differently under the proposal than in IE, in 
> ways that may break intended behavior. Past studies (for example, 
> looking for copy-paste embedded SVG in text/html) imply this may be 
> fairly common.

http://philip.html5.org/data/xmlns-attributes.txt has some numbers for 
this kind of thing.

-- 
Philip Taylor
pjt47@cam.ac.uk
Received on Thursday, 1 October 2009 21:47:58 UTC

This archive was generated by hypermail 2.3.1 : Monday, 29 September 2014 09:39:08 UTC