Re: XHTML m12n XSD

[Rick Jelliffe <ricko@allette.com.au>]

From: Mike.Champion@SoftwareAG-USA.com
>  > 3. XHTML is more a doucment format than a data format, so the
> > reasoning is slightly blurred

> DTDs are too limited to be used effectively for "data", but never heard
that
> XSDs are not fully suitable for "documents".

Lets take an example of XSL-FO. Inside the box, it is a tree in which a node
can override certain properties of its ancestor--but if the ancestor does
not have those properties, the node cannot.  In XML Schemas, to simulate
this would require an exploding number of declarations and type/element
names.  XML Schemas is no worse than DTDs for handling inheritence effects
but not much better: indeed, if the inheritance effect comes from an
ancestor and there can be lots of different properties effected, there is a
combinatorial explosion than makes it impractical to model.  (One would make
a slack schema allowing everything, then use Schematron to detect
co-occurrance constraints.)

Is XSL-FO "data" or a "document"?    I think the better distinction is
between "inheritence-flat" documents (e.g. database data) and
"inheritence-rich"  documents (e.g. idiomatic markup languages and
executable languages).

Cheers
Rick Jelliffe