Hi Priscilla,

Yes, that should be a "familiar" example.

Thanks for your reply and your excellent book.  It was worthy of all the
praise it received on Amazon.com, which was the deciding factor in my
purchase.

As I remember that your are on various XML committees, I'd like to offer
some input for XML futures.

It occurs to me that it is both HIGHLY desirable and feasible for any
XML application that uses a particular Schema (let's call it "Generic
Products") to be able to process an XML document that is basic on Schema
that EXTENDS the base schema, as would be the case with group
substitutions so long as it has access to the extension.

This would allow me to write out XML apps in the extension - which I
might do for a number of reasons such as use of the extensions, brevity,
human readability, etc. - but still be to have XML apps that process the
base Schema be able to handle documents written in the extension.

That is, to a "Generic Products" that isn't prepared to handle <Shirt>,
it can see/handle it as just a "Product" as is commonly done in OO (C++,
Java,...).   All the XML parser needs is access to the extension Schema
and a bit of instruction to tell it to "hide" the extension.

As far as I know (and I'm still learning XML), there are a few things
that prevent you from doing this, such as what we've discussed.

In short, I think the capability to process extensions "as if" they were
they were NOT extensions would be an incredibly valuable "next step" for
the XML world.

Perhaps this has already been discussed, as it almost seems an obvious
"want list" item.

Thanks again,

     Dave Blickstein

*** Sent via Developersdex http://www.developersdex.com ***