XHTML2 and modularity (was Re: Feedback on XHTML 2.0 WD (20030131))

[ CAVEAT: Personal opinion, not representing the HTML WG in any way ]

Reordered the thread a bit ...

Herr Christian Wolfgang Hujer <Christian.Hujer@itcqis.com> wrote:

> > | 4. XHTML 2.0 Document Type
> > | I'd like to see XHTML 2.0 also include MathML, not just XForms.
> > | (I know that's just a wish)

Toby A Inkster <tobyink@goddamn.co.uk> wrote:

> > Would be nice. Perhaps, create two versions of XHTML2:
> >
> > 	* Standard
> > 	* Enhanced
> >
> > With "Enhanced" including support for SVG, MathML, etc. That way, people
> > can include more appropriate XML-based markups in their documents
> > without sacricifing that "Valid XHTML" button.

Herr Christian Wolfgang Hujer <Christian.Hujer@itcqis.com> wrote:

> I agree with that.
> Currently this is achieved by "Profiles", I think, "Profiles" are too far away 
> from the normal HTML / XHTML Recommendations and I fear companies like MS 
> won't support SVG until it is mentioned as part of an XHTML recommendation 
> itself.

Brant Langer Gurganus <brantgurganus2001@cherokeescouting.org> wrote:

> > I don't think MathML belongs in XHTML, but there should be a DOCTYPE 
> > variant that includes it and SVG.

Herr Christian Wolfgang Hujer <Christian.Hujer@itcqis.com> wrote:

> I agree. Of course, MathML definitely isn't part of XHTML. As well as XForms 
> is not part of XHTML.
> I think the profile containing SVG and MathML should be part of the XHTML 2.0 
> Recommendation and not an additional one. Otherwise I think MS and some other 
> vendors will continue to refuse in supporting SVG and MathML.

I'd rather hope that XHTML2 itself should remain simple and small
rather than trying to put everything in it.  Instead, it should
clearly define how XHTML2 is supposed to work together with other
vocabularies such as MathML and SVG, probably in accordance with
the TAG issue mixedUIXMLNamespace-33: "Composability for user
interface-oriented XML namespaces" [1].

Experience from XHTML modularization clearly shows that different
people have different needs, e.g. some people may want to add SMIL
and other people may want to integrate VoiceXML, whereas another
people may want to subset them, and so on.  We can hardly define
one "Enhanced" profile that would suit most people's needs.  IMHO
XHTML2 per se should be just one building block, and we'd better
let people build what they want.

At the same time we should well balance people's desire to be able
to mix various vocabularies as easily as possible, against people's
desire to be able to validate such a compound document.  Close
integration may still require some expertise, but just putting
something inside something and validate it shouldn't require deep
knowledge of schema languages, namespaces and such.

I've been investigating how to satisfy these rather conflicting needs.
One of possible approaches would be Modular Namespaces (MNS) [2],
for example, so far I've made an MNS schema for 
XHTML2+MathML+SVG+EGIX+ContactXML+HLink+RDF+XMLCharEnt [3] (plus
a few others, may add more), and a sample document mixing all of
them [4] can be validated against this MNS schema.  Still it's
*a lot* simpler than building the XHTML+MathML+SVG DTD.  With
proper guidance, I hope people can manage to build their favorite
profile without too much effort.  For validation, I would be very
grateful if ISO/IEC 19757-4 (a.k.a. DSDL VCSL, work in progress)
could make it even simpler.

WARNING: The sample document [4] is primarily for testing validation
  of compound document, not for rendering.  I'd recommend not to try
  to render it.  It may crash your browser.  If you're a fearless
  vanguard, however, you'd better use Gecko-based browsers, such
  as Mozilla/Netscape 7/Camino/Phoenix/... .  You'd need math fonts
  to render MathML, and an SVG-enabled build to render SVG.  Style
  sheets are less than alpha release quality, those are tailored to
  this particular instance and not generally usable.  It's just
  a prototype.  Again, it may crash your browser, in particular
  links are dangerous.  Sane people shouldn't try it.

[1] http://www.w3.org/2001/tag/ilist#mixedUIXMLNamespace-33
[2] http://www.thaiopensource.com/relaxng/mns.html
[3] http://www.w3.org/People/mimasa/test/schemas/rng/hybrid.mns
[4] http://www.w3.org/People/mimasa/test/xhtml2/hybrid

Regards,
-- 
Masayasu Ishikawa / mimasa@w3.org
W3C - World Wide Web Consortium

Received on Friday, 28 March 2003 06:23:47 UTC