Web services package

• Tommy investigate what a good web service library that can be integrated with VisTrails
  • Emanuele's pointers:
    • It is important to have in mind that we need to create Modules for methods and types on the fly. ZSI provided a way to generate class stubs for all methods and types in a wsdl file and VisTrails used those to create the Modules. I believe the other libraries can't do that so we might have to do that ourselves.
    • Potential library: SUDS (https://fedorahosted.org/suds/)
      • Tommy: It looks like a good alternative.
      • Simple interface
      • The WSDL can be cached in different ways.
      • Complex types can be stored as dict's.
    • This page on stackoverflow can also be useful: What's the best SOAP client library for Python, and where is the documentation for it?
    • Here's how Taverna handles Web Services:
      • http://www.taverna.org.uk/introduction/services-in-taverna/ the model is that any "plain" SOAP service can be used immediately, given the URL of its WSDL specification, while some special collections like caGrid, Biomoby and other services need a Taverna plugin to be used, due to their specific requirements (regarding security, for example).
      • They use Axis 1 to parse WSDLs and call web services, but built an overlay on top of Axis1 to do higher-level support, for instance caching of XSDs and header support.
      • REST support is currently under development with an alpha due out in September.