Limit exclusive key-value pairs in XSD

Question

There are two elements to the XSD: A and B. They are siblings.

A may have a value of "1" or "2". B may be one or two.

I want to limit this, however, so that only “1-on” and “2-two” are valid combinations, not “1-two” or “2-one.” Is there any way to do this in XSD?

Answer 1

Schematron can be used to identify such co-occurrence constraints. Here you can find some introductory articles:

• Improving XML Document Validation with Schematron
• Schematron: XML structure validation language using templates in trees