Remembering the Future

There are some interesting points about the general naivete of assuming that you can design a single schema (or even use a single schema language ;-) for an entire system of any complexity. I did a talk at the Applied XML DevCon last fall that described how the system I've been working on uses multiple schemas for the same XML dialect in order to assert different things at different points

. . . The big issue in the Web Service space is the definition of a contract. If your schema is a localized view, how do you specify a shared contract? The WS-* specs define it in prose. But then how do you test it for compliance? There in lies the problem. Arguably each party should use schema that enforces as many requirements as they care to assert. Getting people to accept that view is an uphill battle.