Re: SAX2 ... missing features?

[Rob Lugt <roblugt@elcel.com>]

From: "David Brownell"

> > - Specifying the root name decl can be problematic when validating
multiple
> > documents of different types.
>
> That decl is one of the three parts of the Document "Type" Declaration
though.
>
>
> >    Our XML Validator [2] enables the user to
> > specify a DTD URL on the command line as well as a list of files to
> > validate.  The xml files may contain different root elements, yet they
could
> > all be valid with reference to the supplied DTD.
>
> No they can't, because they won't test the Root Element Type VC,
> which is supported by the DTD.  (Not external or internal subsets;
> but by the whole DTD!)
>
>
> > - For packaging reasons, applications may want to keep a private,
in-memory
> > copy of an entire DTD.  The InputSource approach allows this to be
passed to
> > the xml parser as a StringReader.  Your approach also allows this, but
in a
> > more restricted way.
>
> I don't see how supporting the _full_ DTD functionality can ever
> be "more resticted" than providing part of it (only external subsets).
> But it's morning, maybe I'm being dense.
>
>
> > - The systemId/publicId ultimately resolve to an InputSource anyway.  By
> > providing the InputSource directly, the application is short-cicuiting
the
> > EntityResolver.  I believe this is a reasonable thing to do, but I'm
open to
> > arguments as to why this may be inappropriate.
>
> Well, for the "external subset" portion of a DTD, one could discuss
> such things.  Not for the "internal subset" (which you didn't address
> in your response), or the declaration of the root element type (which
> you "can't see any sense at all in").
>
> If one really wants a single object to pass in to the parser to describe
> the DTD, it should include all three parts of the DTD.
>

Not wishing to be pedantic, but the distinction between a DTD and the
DOCTYPE declaration was raised on this list a while ago (by Elliot Rusty
Harold if I remember correctly).  A DTD really only has two "parts" - an
internal and an external subset.  The name to which you refer belongs to the
DOCTYPE declaration, not the DTD.

The Root Element VC reads "The Name in the document type declaration must
match the element type of the root element".
I would think that when a document does not contain a DOCTYPE declaration it
is rather difficult to check the Root Element Type VC!

So, I think that your proposed API is good for inserting a DOCTYPE
declaration, but I question the value of this.  I do, however, see great
value in being able to specify a DTD to use for validation.  I don't think
that an internal subset is useful, but perhaps others can see some value in
this.

Regards
~Rob

--
Rob Lugt
ElCel Technology
http://www.elcel.com/