Using a WSDL with abstract types in PHP

Question

I\'m working on an integration between our web application and Microsoft Exchange 2007. I am using Exchange Web Services (EWS) to communicate to the Exchange Server. Howev

Answer 1

You can use substitutionGroup only with global elements not with types. The same with

if you use a ref reference you need a element and not a type!

A other approache is just to use abstract types and XMLSchema-instance (xsi:type) instead and leave the substitutionGroup as you did.

This may explain that a bit better as i did. http://www.xfront.com/ExtensibleContentModels.pdf