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I think this is a sensible question but am happy to be pointed out the
error of my ways.

I am specifying a new product for which I would like to have an XML
Schema interface (not sure whether W3C or Relax NG as yet). I would
also like to have a DTD that describes the same interface for those
clients who are unable to use Schemas for one reason or another. Is it
possible to generate a DTD from a given Schema ? I can seem to find
lots of things about specific tools generating DTD's and Schemas from
a given XML document.

However logically I would like to maintain one schema for which I can
then generate an equally valid DTD and also example XML documents.

BTW: I would ideally like this to be possible from either command line
such that it can be hooked into the build process or from some kind of
Emacs mode ?

Appreciate any help in advance.....

--
Rob Exley

Rob Exley wrote:

> I think this is a sensible question but am happy to be pointed out the
> error of my ways.
>
> I am specifying a new product for which I would like to have an XML
> Schema interface (not sure whether W3C or Relax NG as yet). I would
> also like to have a DTD that describes the same interface for those
> clients who are unable to use Schemas for one reason or another. Is it
> possible to generate a DTD from a given Schema ? I can seem to find
> lots of things about specific tools generating DTD's and Schemas from
> a given XML document.
>
> However logically I would like to maintain one schema for which I can
> then generate an equally valid DTD and also example XML documents.

I am not going to say that it is not solvable but at least a W3C XML
schema can specify/constrain a lot of things a DTD can't do, for
instance if you use some regular expression pattern to restrict the
value of an element or attribute how would you want to express that in a
DTD?
--

Martin Honnen
http://JavaScript.FAQTs.com/

Martin Honnen <> wrote in message news:<>...
> Rob Exley wrote:
>
> > I think this is a sensible question but am happy to be pointed out the
> > error of my ways.
> >
> > I am specifying a new product for which I would like to have an XML
> > Schema interface (not sure whether W3C or Relax NG as yet). I would
> > also like to have a DTD that describes the same interface for those
> > clients who are unable to use Schemas for one reason or another. Is it
> > possible to generate a DTD from a given Schema ? I can seem to find
> > lots of things about specific tools generating DTD's and Schemas from
> > a given XML document.
> >
> > However logically I would like to maintain one schema for which I can
> > then generate an equally valid DTD and also example XML documents.
>
> I am not going to say that it is not solvable but at least a W3C XML
> schema can specify/constrain a lot of things a DTD can't do, for
> instance if you use some regular expression pattern to restrict the
> value of an element or attribute how would you want to express that in a
> DTD?

I am happy to lose validation information that I have no way to
specify in the DTD as long as the structure and relationships
cardinality etc are maintained. I appreciate that using schemas I can
provide a lot better validation for any documents using the schema.