Re: shape.dtd, diagram.dtd

[Andrew Ferrier <andrew junk new-destiny co uk>]

On 2002-07-11 at 03:50 -0400, James K. Lowden wrote:

> > I'm not so sure that's true, is it? It depends on how much
> > knowledge the generation/conversion utility has about .dia
> > files, surely? If it was specific (as in the case of
> > sql2dia), would not DTD validation just be a 'safety net'
> > to ensure that sql2dia had not screwed up and accidentally
> > created invalid .dia files? Surely it would have to be
> > creating what it believed were valid .dia without reference
> > to the DTD, unless it is going to read the DTD, parse it,
> > understand it, and create files in accordance with it, in
> > which case isn't it doing all the work of a DTD validator
> > and more itself?
>
> Oh, that's what I meant, more or less.  Suppose you want to
> create a .dia file from scratch; what you have is a some data
> and an idea, but no Dia.  Surely one approach would be to
> read the DTD, and use it with a validator to verify your
> output.  Whether or not your output library actually takes
> advantage of the DTD is a separate question, at least to me.

OK, I understand what you mean now. In fact, I would go
further: I would be suprised if your output library even looked
at the DTD. But validation might be a good safety to check your
program, though you might want a compile-time switch to turn
off the validation if you were confident of your output
mechanism. It would certainly help YOU during debugging (I say
this from experience having used an XML schema for the same
purpose in some simulation software I recently wrote).

Regards,
Andrew.

-- 
Andrew Ferrier

email: andrew junk new-destiny co uk
web:   http://www.new-destiny.co.uk/andrew/