- From: Sam Ruby <rubys@intertwingly.net>
- Date: Tue, 10 Apr 2007 23:12:49 -0400
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 <rubys at intertwingly.net> >>> 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
Received on Tuesday, 10 April 2007 20:12:49 UTC