Re: XML Validity and DTD dependance

Rich Salz scripsit:

> >   The validity constraints that you say are
> > on the document itself are ones that *could* be specified by some
> > other mechanism than DTDs, such as XML Schemas.
> 
> Yes.

I think Richard Tobin conceded too much here: see below.

> >   It seems you want a term meaning "valid according
> > to whichever kind of schema I am using", and I think it would be very
> > confusing to adopt the plain term "valid" for that, when it has been
> > used for so long in both SGML and XML to mean "DTD valid".
> 
> No.  I want a term for "the instance document meets every single
> validity constraint from the XML spec, except that no DTD is present."

That's simply self-contradictory.  Another schema language may have a
*different* constraint that is generally analogous to the XML validity
constraint Element Valid (to pick the first one from your list), but it
isn't the *same* constraint, and there's no a priori method of figuring
out which one it is.  For example, what is analogous to Element Valid
using a Schematron schema?

And so on for the rest of the list.  It's perfectly well-defined to
talk about XML validity (that is, self-consistency), or W3C XML Schema
validity, or Schematron validity, or RELAX NG validity (all three with
respect to external schema documents), or even Hook validity (which is
a different kind of self-consistency).  But adopting the list of XML
validity constraints and saying that they make sense WRT a different
schema language, no.

> Then the XML spec needs to be revised to make DTD's namespace
> aware, don'tcha think?  Or do you really think that the only way
> realistic way to have valid XML documents -- or hack, let me show
> my true colors and say "XML messages -- is to not use namespaces?

Use XXX validity for your favorite XXX.  If existing schema languages don't
serve your needs, make a new one.  But don't expect it to be incorporated
into the definition of XML.

-- 
So that's the tune they play on                 John Cowan
their fascist banjos, is it?                    jcowan@reutershealth.com
        --Great-Souled Sam                      http://www.ccil.org/~cowan

Received on Sunday, 24 April 2005 16:45:04 UTC