Maciej Stachowiak wrote:
On Apr 10, 2007, at 2:14 PM, Sam Ruby wrote:
Anne van Kesteren wrote:
On Tue, 10 Apr 2007 22:41:12 +0200, Sam Ruby <[EMAIL PROTECTED]>
wrote:
How so?
I missed the part where you wanted to change existing HTML parsers. I
thought Hixie pointed out earlier (by means of examples) why we can't
have namespace parsing in HTML. I suppose we can discuss it again...
It is a recurring pattern. The first instance was "we can't allow
trailing slashes in tags", which was followed up by a carefully
crafted and narrow set of exceptions, which was met with "that works"
and was adopted.
So... while it is clearly true the full extent of XML namespames will
never be supported in HTML5 (and for good reason), namespace qualified
attributes allow extensibility in ways that prevent collisions.
One of the first questions that would need to be answered: are there
any existing documents on the web which would be broken if the name
placed into the DOM for attributes with names containing a colon, with
an apparent prefix, and one that matched an enclosing xmlns:
declaration were to be changed?
I think the problem here isn't compatibility with existing content, but
rather ability to use the feature in new web content while still
gracefully handling existing user agents. We wrote up some design
principles for the HTML WG based on the WHATWG's working assumptions
which might make this point more clear:
<http://esw.w3.org/topic/HTML/ProposedDesignPrinciples>. While "Don't
Break The Web" is a goal, so is "Degrade Gracefully".
To give a specific example: say I make my own "mjsml" prefix with
namespace "http://example.org/mjsml";. In HTML4 UAs, to look up an
"mjsml:extension" attribute using getAttribute("mjsml:extension"). In
HTML5 UAs, I'd have to use getAttributeNS("http://example.org/mjsml";,
"extension"). And neither technique would work on both (at least as I
understand your proposal).
Here's a page I constructed, and tested on Firefox:
http://intertwingly.net/stories/2007/04/10/test.html
This page is meant to be served as application/xhtml+xml.
Can you test it and see what results you get? Then lets discuss further.
BTW, I intentionally don't have a completed proposal at this point. We
need to explore what works and what doesn't work further.
Now, we could extend getAttribute in HTML to do namespace lookup when
given a name containing a colon and when namespace declarations are
present, but then we would want to do it in XHTML as well. And using the
short getAttribute call instead of a longer getAttributeNS with a
namespace prefix might be unacceptable to XML fans.
Regards,
Maciej
- Sam Ruby
