Lists Home |
Date Index |
From: "Bullard, Claude L (Len)" <email@example.com>
> 2. Learn RELAX NG and XML Schemas. Schematron has no official
> standing, but without it, the weaknesses of RNG and XSD aren't
> easy to overcome. Databases typically need the ability to
> specify co-occurrence constraints (if this value, then that
> value). So one needs it.
Schematron is currently being standardized as part of ISO DSDL. I hope
it will be an ISO standard by the end of this year, if everything goes smoothly.
I hope to fold in some of the ideas from the similar XCSL, whose author I met in
Barcelona last week, in particular the <let> element which allows variables
to a certain extent: this will simplify dissecting strings into parts and treating
their parts as numbers (e.g. dates, etc) with interrelationships. At the moment
this is possible but cumbersome.
There are no backward-incompatible changes with Schematron 1.5 planned.
We are definitely targeting ISO Schematron as a convenient way to express
constraints that are difficult or confusing in other schema languages: express
simple relationships in other languages with simple content models, and leave
the complex constraints to Schematron schemas.