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[xhtml2] Namespaces

From: Anne van Kesteren <fora@annevankesteren.nl>
Date: Sat, 21 May 2005 20:38:54 +0200
Message-ID: <428F803E.60006@annevankesteren.nl>
To: W3C HTML <www-html@w3.org>

Today I read:


...which confirmed some rumors about I heard about XHTML2 and XForms. I 
guess XHTML2 will eventually adopt XForms 1.1 that has a new namespace 
specified (using 2004 instead of 2002) and specifies some kind of an 
"inheriting namespace". The latter might need some explanation.

Basically, when a specification — like XHTML2 — embeds XForms, XForms 
inherits the namespace from its 'host markup language'. I already 
expressed some concerns about this on www-forms-editor and got no response:


However, this seems to apply to XHTML2 as well as XHTML2 plans to embed 
XForms that way. Now I don't think this is a good idea. There already 
was the semantic duplication of:


...where xhtml1 and xhtml2 are bound to the XHTML1 and XHTML2 namespace 
respectively. I believe that issue was once raised on this mailing list 
and never resolved.

Now we get this:


...and again the prefixes are bound to the namespaces you expect them to 
be bound too.

I was wondering if this is a good thing and if the namespace idea 
perhaps needs to be looked at again. And if this is considered a good 
thing, if this can be made a W3C policy. Different WGs tend to do very 
different things with respect to namespaces and versioning. (This is a 
problem outside the W3C as well I guess.)

Some examples might help. The HTML WG tends to introduce a new namespace 
for every minor update. See XForms 1.1. They go even further to let 
other languages embed elements from a different namespace in their own 
namespace, which might make it possible that you have something like 
this in the end: xforms1:input, xforms11:input, xhtml2:input, svg:input, 
mathml:input, et cetera all representing the same element with the same 

The SVG WG does not introduce new namespaces and instead uses some kind 
of versioning mechanism to do the job. They also try to not make 
backwards incompatible changes I believe so this is somehow possible.

The XML WG also extends existing namespaces (the XML namespace) — see 
xml:id — and says that should be possible. No kind of versioning and it 
seems to break some applications. But that is mostly because the 
applications are broken.

Perhaps this should be discussed on another list. Please forward in that 
case and please cc me.


  Anne van Kesteren
Received on Saturday, 21 May 2005 18:38:46 UTC

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