Re: Dia & Schemas/DTDs

["James K. Lowden" <jklowden schemamania org>]

On 06 Nov 2002 12:26:43 -0600, Lars Clausen <lrclause@cs.uiuc.edu> wrote:
> On Wed, 6 Nov 2002, Durk Strooisma wrote:
> > 
> > We noticed that Dia doens't make use of DTDs or XML Schemas (for
> > example to validate Dia XML documents). Even correct DTDs or XML
> > Schemas aren't provided, which would be handy to validate Dia XML
> > documents within XML authoring tools.
>
> I don't know enough about DTDs and XML Schemas to judge whether this is
> a useful thing.  We do have DTDs, but they're not used by Dia.

Durk makes a good point.  It would be useful, and it wouldn't be easy for
an outsider to contribute.  Forgive me if I'm belaboring the obvious.  

If Dia relied on its DTD to validate a file prior to/while loading it,
then the DTD would be assured of being a good measure of a good Dia file. 
That would give non-Dia programs a benchmark for creating Dia files.  And
it would assist non-Dia programs in interpreting Dia files.  (BTW, do I
understand correctly that the DTD is a little out of synch with Dia's
expectation of a Dia file?)  

Durk also mentions extending the DTD without changing the source code, to
add attributes to shapes.  I don't see how that's possible, nor do I
understand how XML Schema comes into play.  

--jkl