The “holy grail” of xml messaging architectures is interoperability. This morning I was thinking about the guaranties of this model, of what we can know for sure.
Say I have a web service interface. I can describe the interface using WSDL. However, what guarantee does the service consumer have that I am exposing the right WSDL?
As the service provider, having provided a WSDL document, what guarantee do I have that the service consumer will send a properly constructed XML document?
A similar question can be made about the service response document.
It seems that the guarantee does not exist. If this is true, the advice of the MS xml team makes a lot of sense: assume parts in the chain will fail, assume unexpected structures, and assume structures will change.
What I am hearing is this: “Go low tech. Push xml documents around. When you receive an xml document search for what you need. If you find it, validate it and move on. If you do not find it, trigger fault code.”
Is anyone else hearing the same?