Adding xsi:type and envelope namespace when using SUDS

Question

I need to interact with a SOAP service and am having a lot of trouble doing so; would really appreciate any pointers on this. The original error message was:

org.apache.axis2.databinding.ADBException: Any type element type has not been given

After some research, it turns out that this is a disagreement between SUDS and the server has to how deal with

type="xsd:anyType"

on the element in question.

I've confirmed using SOAPUI and after advice that the problem can be fixed by taking these steps:

1. Adding xsi:type="xsd:string" to each element which causes problems
2. Adding xmlns:xsd="http://www.w3.org/2001/XMLSchema" to the SOAP Envelope

So, where SUDS currently does this:

<SOAP-ENV:Envelope ... xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
<ns3:Body>
  <ns0:method>
     <parameter>
        <values>
           <table>
              <key>EMAIL_ADDRESS</key>
              <value>example@example.org</value>
           </table>
        </values>
     </parameter>
  </ns0:method>

it should instead produce this:

<SOAP-ENV:Envelope xmlns:xsd="http://www.w3.org/2001/XMLSchema" ... xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">

  <ns3:Body>
  <ns0:method>
     ...
     <parameter>
        <values>
           <table>
              <key xsi:type="xsd:string">EMAIL_ADDRESS</key>
              <value xsi:type="xsd:string">example@example.org</value>
           </table>
        </values>
     </parameter>
  </ns0:method>

Is there a correct way to do this? I've seen suggestions of using ImportDoctor or MessagePlugins, but haven't really grokked how to achieve the desired effect.

Answer 1

The solution I found was to use a MessagePlugin to essentially manually fix up the XML just before sending. I'd hoped there was something more elegant, but at least this works:

class SoapFixer(MessagePlugin):

    def marshalled(self, context):
        # Alter the envelope so that the xsd namespace is allowed
        context.envelope.nsprefixes['xsd'] = 'http://www.w3.org/2001/XMLSchema'
        # Go through every node in the document and apply the fix function to patch up incompatible XML. 
        context.envelope.walk(self.fix_any_type_string)

    def fix_any_type_string(self, element):
        """Used as a filter function with walk in order to fix errors.
        If the element has a certain name, give it a xsi:type=xsd:string. Note that the nsprefix xsd must also
         be added in to make this work."""
        # Fix elements which have these names
        fix_names = ['elementnametofix', 'anotherelementname']
        if element.name in fix_names:
            element.attributes.append(Attribute('xsi:type', 'xsd:string'))

Answer 2

It's sad and hilarious, like a lot of things about this particular library, but here's the exact answer:

http://lists.fedoraproject.org/pipermail/suds/2011-September/001519.html

from the above:

soapenv = soapenv.encode('utf-8')
plugins.message.sending(envelope=soapenv)

becomes:

soapenv = soapenv.encode('utf-8')
ctx = plugins.message.sending(envelope=soapenv)
soapenv = ctx.envelope

basically, it's a bug in the implementation, and you can patch it yourself by editing the line that runs the plugin to actually return the plugin's results, but I'm not aware of a patched and updated version of SUDS that fixes this yet (tho I haven't looked closely for it).