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

[Michael Champion <Mike.Champion@softwareag-usa.com>]

----- Original Message -----
From: <keshlam@us.ibm.com>
To: <xml-dev@lists.xml.org>
Sent: Tuesday, August 08, 2000 11:16 AM
Subject: Re: Does DTD validation work with namespaces?


>
> 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;

But one can't thow out DTDs without throwing out entity declarations as
well, and the Schema proposals don't have as powerful modularization
capabilities either (e.g., no conditional marked sections, and I'm not sure
if XInclude in a schema fully replaces the functionality of parameter
entities in a DTD).  So you have to replace DTDs with Schemas + XInclude to
get even barely equivalent functionality ...

So, one really has to ask oneself which combination really meets one's needs
best: DTDs (including entities of various sorts) with limited, globally
unique namespace prefixes; or Schema+XInclude (someday) with full namespace
support.  Neither really does everything you might want, so I can understand
why people would want to extend DTDs to support namespaces!

Can anyone explain why Schemas can't support entity declarations?  That
*would* allow us to "refer folks to the newer schema languages" without much
pain.