OGC Public Forum :

[shawnhermans]

Our group is looking at O&M and are evaluating an approach that restricts the result type (and other parts of the observation) to our specific types. As a starting point, we looked out the following schema. In XMLSpy we get multiple validation errors. One of the validation errors is that the type given for a om:result is an invalid restriction of xs:any. Did you run into these problems when creating this schema?

I understand the alternative is to use Schematron rules, but our the development team is leaning against that. We are trying to find someone of restricting the observation using only XML Schema.

-Shawn Hermans

[kevin]

This from the O&M editor...

A quirk or feature of XML Schema is that it is not possible to do type restrictions across namespace boundaries.
The declaration of the 'result' element in the observation schema follows the rules for GML Application Schemas, so is 'local' to the om:ObservationType.
When you try to define a derivation in another namespace, therefore, it is not possible to restrict the content model of locally declared elements.