RDDL and entities (was Re: Schemas and entities (was"And the DTD says, "I'm NOT dead yet!!")

[Rick Jelliffe <ricko@allette.com.au>]

From: Marcus Carr <mrc@allette.com.au>

> In the event that I wanted to
> employ a dataflow that involved general entities that did more than just
string
> replacement, I would have to:
>   a)  create an instance with entities,
>   b)  process my instance against a DTD,
>   c)  use some means to insert namespaces,
>   d)  validate with a schema-driven processor.

This is a place where RDDL can play a role.

One of the well-known (arc-)roles for RDDL would be public entity sets
used in the document.

A RDDL processor (assuming it to be a SAX post processor) would, apon
finding an unresolved entity reference, ask the RDDL to locate the public
entity
files, download them and perform expansion if possible.

For people who want to ultimately get rid of DTDs (or who want schemas to be
maximally inter-convertable),  I think RDDL support is a requirement.  What
a RDDL document is, in effect, is a Document Type Definition that can
encompass all levels and wrinkles of shematic information, from named
characters to user-defined characters to structural schemas and datatypes,
to business rules and semantic schemas.  If it can be plugged into SAX (and
if someone makes an expat implementation too) that seems to be the best way
to get fast and uniform deployment.

Exciting.

Cheers
Rick Jelliffe