[xml] XML Schema: Validating an instance document with multiple schemas

["Paul B. Cameron" <paul b cameron kepware com>]

I’m porting a Win32 app that uses MSXML to a POSIX environment that will use libxml2. This app uses XML schema for validation.

 

There is basically a ‘main’ schema that (among other things) includes an element with a complex type sequence of ‘any’ type:

 

<xs:element name="Properties" minOccurs="0">

          <xs:complexType>

                   <xs:sequence>

                             <xs:any namespace="##other" processContents="strict" minOccurs="0" maxOccurs="unbounded"/>

                   </xs:sequence>

          </xs:complexType>

</xs:element>

 

The idea is that the app data model is extensible, and that the ‘any’ node will contain data that will declare a new namespace and be validated by a different schema. These schemas are not currently designed to use schema include (xs:include).

 

The MSXML parser allows multiple schemas to be loaded into a collection, which is then associated with the document that is to be validated. However, it looks like the libxml2 schema API is designed to work with one schema/context at a time. Am I correct?

 

Thanks in advance,

- Paul