Re: dtds

Daniel Veillard <[email protected]>
Newsgroups gmane.linux.rpm.metadata
Message-ID <[email protected]>
On Tue, Nov 04, 2003 at 12:08:02AM -0500, seth vidal wrote:
> >   that's basic but should work
> 
> Is there a good place to go for more advanced dtd documentation?

  Argh, bad question ... you would end up with SGML related DTD
stuff like Eve Maler book. XML has a restricted use of DTDs,
and they are now considered "legacy", current XML practices
are moving out of them due to their restrictions

> > > http://linux.duke.edu/~skvidal/metadata/rpm-ns.dtd
> > 
> >   Hum, DTDs do not understand namespaces. So extensibility with DTDs will
> > be a pain anyway. I'm surprised to not see any ATTLIST allowing xmlns
> > kind of attributes (they are attributes at the DTD level).
> >   I'm not sure you can assemble your split DTD and make it usable easilly
> > especially if one start using non default namespace prefixes.
> 
> So what are you specifying when you specify a namespace? How do you
> define what things are appropriate in the namespace, I thought that was
> what you needed the dtd for.

  The DTD defines a vocabulary, but has no notion of namespace.
Only recent spec like XML Schemas or Relax-NG integrates the notion
of namespace (and data typing) at the schemas level. I have a strong
bias toward Relax-NG myself.

Daniel

-- 
Daniel Veillard      | Red Hat Network https://rhn.redhat.com/
[email protected]  | libxml GNOME XML XSLT toolkit  http://xmlsoft.org/
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