Another look at namespaces

[Shane P. McCarron]

"Simon St.Laurent" wrote:
> Is there _anything_ else besides their names that distinguishes these flavors?

Sure.

XHTML Frameset has a completely different content model than the other
two. Its root element is html, but that html element may NOT contain a
body element. Instead, it contains a frameset element that defines the
collection of frames. These frames have some weird inherent behaviour
that cannot be described by existing schema technology (various panels
are defined in the window, one per defined frame). To be clear, an XHTML
Frameset document as NO CONTENT.  Instead, it refers to content.  Is
this stupid?  Sure. However, it is a faithful representation of HTML
4.0.

XHTML Transitional has a different content model than Strict in that it
is more permissive.  XHTML Transitional may be a superset of XHTML
Strict, but I have never done the evaluation to be certain. I am certain
that they are significantly different. In particular, XHTML Transitional
contains all sorts of stuff that is eliminated in XHTML 1.1. XHTML
Strict only has a few items that are removed in XHTML 1.1 (e.g. the name
attribute on the a element is eliminated in favor of the id attribute).

> >Information about those namespaces may, if the W3C chooses to follow this
> >path, be obtained from a schema, DTD, or other data source at the end of
> >that URI.
> 
> Or, since this is an XML 1.0 application, you could just read the DOCTYPE
> declaration and not try to map namespace URIs to places where the W3C might
> (but won't comment on publicly at present) want to go someday.

Absolutely. And, since XHTML 1.0 requires a DOCTYPE declaration, you can
be confident that one will be present in XHTML 1.0-conforming documents.
Moving forward, as the HTML Working Group completes its work on Document
and Client profiles (which might just be requirements to CC/PP, who
knows), I expect that the group will define elements that allow document
authors specify:

	a pointer to a document profile
	a complete, embedded document profile
	information about the schema
	information about how the schema is based upon other, well known 
		schema (like XHTML)
	etc.

However, that is a future problem. The current problem is finding a way
through this morass so that we can publish the first baby step toward a
better, more interoperable web. That is XHTML 1.0.  What do we need to
do to get on with it?

--
Shane P. McCarron                  phone: +1 612 434-4431
ApTest                               fax: +1 612 434-4318
                                  mobile: +1 612 799-6942
                                  e-mail: shane at aptest.com

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