Re: [xml-dev] Schematron Best Practice: Embed Schematron into a Grammar-Based Language? Or Keep Separate?

Costello, Roger L. said:

> ISSUE
>
> You have a set of data validation requirements for your system.  You
> have decided to implement the requirements using a combination of a
> grammar-based language (e.g. Relax NG or XML Schema) plus Schematron.
> Should the Schematron implementation be embedded within the grammar
> document, or should the Schematron implementation be in a separate
> document from the grammar document?

3) Or should the grammar productions be embedded inside the Schematron
schema?

For example, in the following, the element declarations would be extracted
and completed based on the

<sch:rule context="Document" role="element-constraints"
   see="http://www.eg.com/requirements/R.1234" >

  <xsd:complexType>
     <xsd:complexContent>
        ...
  </xsd:complexType>

  <sch:assert test="..." role="security-constraint" >...

</sch:rule>

4) Or should you have *both* embedded and separate Schematron schemas?
With the division be made on topical lines, it ensures a logical
separation of concerns, which can fit in better with organizational
structures and reduce tasking interdependencies.

For example so that all the security-related issues are gathered together,
to allow easy maintenance. But non-security related constraints are all
bundled together in the main schema document.

<sch:pattern>
   <sch:title>Security-related Constraints</sch:title>

   <sch:rule context="Document">
      ...


Cheers
Rick Jelliffe