Limitations of the Dynamics Ax Service references

Service references are WebService Proxies generated by Ax 2009 with the tool svcutil.exe based on Wsdl files. Creating a Service reference is very easy and well documented on msdn and it was never been easier to consume WebServices with X++ if the Wsdl of the WebService is compatible with Dynamics Ax. Wsdl files are normally generated by the WebService which is in almost every case based on a SOAP engines like the Cape Clear or Axis. These ‘Service References’ are providing the interoperability between the WebService and Dynamics Ax 2009 as consumer (see ‘consume a WebService from X++’ and the whitepaper). There are some comatibility limitations known:

1. No support for SOAP headers
   
2. Client-code must be executed on the server (AOS)
   
3. Limited authentication support (you cannot authenticate with a different user account) due the missing impersonation support on the AOS
   
4. Service references only support Wsdl with only one service group
   
5. Only services with Document/literal binding style

You can workaround these limitations (Points 1-4) by creating manually the WebService-proxy as it was necessary with Dynamics 4 with the wsdl.exe tool.

Regarding point 5, the workaround can be writing a custom WebService proxy or to ask the WebService provider to expose his service with Document/literal style. WebService-Server such as Axis do support both types, so it might be possible to change the configuration on the server side. The article from Russell Butek describes and compares the possible choices.

If it is not possible to change the binding-style (for example if the service is using overloaded methods or if the provider refuses is), the only possible workaround is to create manually the WebService-proxy then to decorate the WebMethod with the SoapRpcMethod-Attribute and to reference this assembly as it was done for Dynamics Ax4. This because neither the asmx.exe tool (ASP.Net-WebServices), nor the svcutil.exe (WCF-Services) do support the RPC-binding-style.

A great source of knowledge about the interoperability between .Net and WebSphere is the IBM Redbook (WebSphere and .Net Interoperability Using Web Services) and the msdn article about customizing SOAP Formatting.