SUDS - programmatic access to methods and types

Question

I'm investigating SUDS as a SOAP client for python. I want to inspect the methods available from a specified service, and the types required by a specified method.

The aim is to generate a user interface, allowing users to select a method, then fill in values in a dynamically generated form.

I can get some information on a particular method, but am unsure how to parse it:

client = Client(url)
method = client.sd.service.methods['MyMethod']

I am unable to programmaticaly figure out what object type I need to create to be able to call the service

obj = client.factory.create('?')

res = client.service.MyMethod(obj, soapheaders=authen)

Does anyone have some sample code?

Answer 1

Okay, so SUDS does quite a bit of magic.

A suds.client.Client, is built from a WSDL file:

client = suds.client.Client("http://mssoapinterop.org/asmx/simple.asmx?WSDL")

It downloads the WSDL and creates a definition in client.wsdl. When you call a method using SUDS via client.service.<method> it's actually doing a whole lot of recursive resolve magic behind the scenes against that interpreted WSDL. To discover the parameters and types for methods you'll need to introspect this object.

For example:

for method in client.wsdl.services[0].ports[0].methods.values():
    print '%s(%s)' % (method.name, ', '.join('%s: %s' % (part.type, part.name) for part in method.soap.input.body.parts))

This should print something like:

echoInteger((u'int', http://www.w3.org/2001/XMLSchema): inputInteger)
echoFloatArray((u'ArrayOfFloat', http://soapinterop.org/): inputFloatArray)
echoVoid()
echoDecimal((u'decimal', http://www.w3.org/2001/XMLSchema): inputDecimal)
echoStructArray((u'ArrayOfSOAPStruct', http://soapinterop.org/xsd): inputStructArray)
echoIntegerArray((u'ArrayOfInt', http://soapinterop.org/): inputIntegerArray)
echoBase64((u'base64Binary', http://www.w3.org/2001/XMLSchema): inputBase64)
echoHexBinary((u'hexBinary', http://www.w3.org/2001/XMLSchema): inputHexBinary)
echoBoolean((u'boolean', http://www.w3.org/2001/XMLSchema): inputBoolean)
echoStringArray((u'ArrayOfString', http://soapinterop.org/): inputStringArray)
echoStruct((u'SOAPStruct', http://soapinterop.org/xsd): inputStruct)
echoDate((u'dateTime', http://www.w3.org/2001/XMLSchema): inputDate)
echoFloat((u'float', http://www.w3.org/2001/XMLSchema): inputFloat)
echoString((u'string', http://www.w3.org/2001/XMLSchema): inputString)

So the first element of the part's type tuple is probably what you're after:

>>> client.factory.create(u'ArrayOfInt')
(ArrayOfInt){
   _arrayType = ""
   _offset = ""
   _id = ""
   _href = ""
   _arrayType = ""
 }

Update:

For the Weather service it appears that the "parameters" are a part with an element not a type:

>>> client = suds.client.Client('http://www.webservicex.net/WeatherForecast.asmx?WSDL')
>>> client.wsdl.services[0].ports[0].methods.values()[0].soap.input.body.parts[0].element
(u'GetWeatherByZipCode', http://www.webservicex.net)
>>> client.factory.create(u'GetWeatherByZipCode')
(GetWeatherByZipCode){
   ZipCode = None
 }

But this is magic'd into the parameters of the method call (a la client.service.GetWeatherByZipCode("12345"). IIRC this is SOAP RPC binding style? I think there's enough information here to get you started. Hint: the Python command line interface is your friend!