[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: Schematron (was Re: Remember to RELAX)

  • From: Rick JELLIFFE <ricko@g...>
  • To: xml-dev@l...
  • Date: Wed, 02 Aug 2000 20:07:37 +0800

schematron wai
Oliver Becker wrote:
> Hi Rick,
> Would it be reasonable to change Schematron into a real open source
> project supported by several contributors (hosted on sourceforge, for
> example)?

Yes. The cunning plan is to make Schematron more

 *) innovator/implementor friendly -- I have been thinking about
Sourceforge and improving the API

 *) brandable -- corporate developers will not be keen to integrate
Schematron into their products unless it has some perceived usefulness
by buyers: to help this we are looking at some trademarking and branding
issues--but to protect and promote only--it will still be free and open;

 *) integratable into XML Schemas and RDF -- initially this will be just
a preprocessor for embedded Schematron schemas in XML Schemas: when used
a type-aware DOM or type-aware XPath, Schematron automatically inherits
XML Schemas typing information for free!

> Unfortunately I don't have any experience with that.

It is a goo time to start. I will try to get it organized for the first
week of September, after I come back from my holiday in Australia.
> Schematron is very fine - but sometimes limited. So I add things myself
> and write proprietary Schematron preprocessors (using an extended
> Schematron language). Other users might do similary things ...

I wonder if there is a way to ramp up the new architecture to support
other elements/attributes in different namespaces as extensions better.
In other words,
can we make the new architecture itself dynamically extensible.  What I
am thinking of is that if you add extensions in a new namespace, we
provide a mechanism to register the default skeleton handlers for it as
> I think a little effort to concentrate the Schematron activities makes
> a lot of sense.

It is a wide-open field. There are many interesting and useful
directions available. The ones I am interested in include:

The theoretical issues about using a schematron schema as a system of
constraints (i.e. to allow checking of rule clashes and for building
smart editors) have not been worked on (I think there is a University in
US doing this for XML Schemas).  

The WAI people have asked about moving Schematron to do repair as well
as diagnosis: how?   

Do we need a generic API for error-reporting/diagnostics? The current
line-based format (i.e., the EMACS format used by XED and
schematron-message) is nice, but the resulting data is not rich: if we
had a generic API (e.g. Exception Reporting Routines--ERR), then
developers could plug different schema languages and implementations in:
SAX or DOM in, ERR out. 

Paul Prescod and Dan Connolly have been building intersting applications
on top of XPath based assertion systems: can these be folded into

How to declare that particular XSL extensions are being used. XSL has
the hooks we need for this already.

One area that I am deliberately not persuing is to get Schematron to
parse or simulate content models in any detail: it would be possible
multiple nested rules, but not very efficient.  But I think
grammar-based schemas are to a certain extent a convenient hack rather
than embodying good software engineering or modeling principles, and I
am not interested in getting into any competition with XML Schemas/XDR
or RELAX/DSD or SOX or DTDs.  If Schematron has a future, I think it has
to have a distinct character and niche to other schema languages.

Rick Jelliffe


Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced!

Buy Stylus Studio Now

Download The World's Best XML IDE!

Accelerate XML development with our award-winning XML IDE - Download a free trial today!

Don't miss another message! Subscribe to this list today.
First Name
Last Name
Subscribe in XML format
RSS 2.0
Atom 0.3

Stylus Studio has published XML-DEV in RSS and ATOM formats, enabling users to easily subcribe to the list from their preferred news reader application.

Stylus Studio Sponsored Links are added links designed to provide related and additional information to the visitors of this website. they were not included by the author in the initial post. To view the content without the Sponsor Links please click here.

Site Map | Privacy Policy | Terms of Use | Trademarks
Free Stylus Studio XML Training:
W3C Member
Stylus Studio® and DataDirect XQuery ™are products from DataDirect Technologies, is a registered trademark of Progress Software Corporation, in the U.S. and other countries. © 2004-2013 All Rights Reserved.