xml-dev - Re: Does DTD validation work with namespaces?

[keshlam@us.ibm.com]

>This isn't the first time this issue has come up.  What's striking is that
the
>proponents of the opposing views (namespaces work with DTD's; they don't)
treat
>the answer as obvious and hardly worth discussion.

The problem is that people are using different definitions of "work with".

As noted, you can write a DTD and a namespace-aware document so that the
latter is valid against the former. This is of minimal utility -- it
requires that you lock in specific prefixes, and specific places where
those prefixes can be defined (unless you play some ugly games with
parameter entities), and it validates only the QNames -- which, in the
Namespace view of the universe, are among the least interesting
information.

If you want proper namespace-aware validation, you'll have to switch to the
XML Schema language or one of its competetors. DTDs simply will not get you
there.

There have been proposals to extend DTDs to handle namespaces. The usual
response is to refer folks to the newer schema languages. The sole
justification for DTD syntax is compatability with SGML schemas; I don't
think we can retain that while extending them to be namespace-aware, and if
we're going to give that up we might as well switch to instance syntax and
simplify parsing.