Bill Burke on problems with XML schema
As you rev your service and your schema you’re going to have to support a lot of different media types. What would make things easier is if XML Schema supported polymorphism. That way a client could ask for “application/vnd1+xml” format and still receive and validate a newer version of the schema. Please correct me if I’m wrong, but I don’t think you can do this in XML schema. Yes you could extend various types from the parent to create a newer version of a schema, but a validator would not be able to enforce a polymorphic relationship with its parent AFAIK.
XML can deal with this problem, but not XSD (with some exceptions). The solution is to throw the schema to the wind.
