I've been interested in generating WSDL from the Flickr reflection
methods to generate a library that could better keep up with the
changes in the Flickr APIs. However, I've run into a problem that
stems from what I believe to be either unorthodox SOAP syntax in
Flickr -- or just the limitations in my own understanding of WSDL and
SOAP.

Here's what I did. I first set out to invoke the flickr.test.echo
mthod (http://www.flickr.com/services/api/flickr.test.echo.html) by
generating the right WSDL to call the flickr.test.echo SOAP method.
The documentation for SOAP invocation is found at
http://www.flickr.com/services/api/request.soap.html

The following SOAP message works with the Flickr SOAP endpoint
(http://api.flickr.com/services/soap/)

<?xml version='1.0' encoding='UTF-8'?>
<s:Envelope xmlns:s='http://www.w3.org/2003/05/soap-envelope'
xmlns:xsi='http://www.w3.org/1999/XMLSchema-instance'
xmlns:xsd='http://www.w3.org/1999/XMLSchema'>
<s:Body>
<x:FlickrRequest xmlns:x='urn:flickr'>
<method>flickr.test.echo</method>
<api_key>e81ef8102a5160154ef4662adcc9046b</api_key>
</x:FlickrRequest>
</s:Body>
</s:Envelope>

You can try this out with curl:

curl -d "<?xml version='1.0' encoding='UTF-8'?><s:Envelope
xmlns:s='http://www.w3.org/2003/05/soap-envelope'
xmlns:xsi='http://www.w3.org/1999/XMLSchema-instance'
xmlns:xsd='http://www.w3.org/1999/XMLSchema'><s:Body><x:FlickrRequest
xmlns:x='urn:flickr'><method>flickr.test.echo</method>
<api_key>e81ef8102a5160154ef4662adcc9046b</api_key></x:FlickrRequest></s:Body></\
s:Envelope>"
http://api.flickr.com/services/soap/

The problem I'm running into now is to how to get this SOAP call
expressed in WSDL. My first shot is:

<definitions xmlns="http://schemas.xmlsoap.org/wsdl/"
xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/"
xmlns:tns="http://mashupguide.net"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
targetNamespace="http://mashupguide.net" name="FlickrService">
<message name="flickr.test.echo_Request">
<part name="method" type="xsd:string"/>
<part name="api_key" type="xsd:string"/>
</message>
<message name="flickr.test.echo_Response">
<part name="response" type="xsd:string"/>
</message>
<portType name="flickr.test.echo_PortType">
<operation name="FlickrRequest">
<input message="tns:flickr.test.echo_Request"/>
<output message="tns:flickr.test.echo_Response"/>
</operation>
</portType>
<binding name="Flickr_Binding" type="tns:flickr.test.echo_PortType">
<soap:binding style="rpc"
transport="http://schemas.xmlsoap.org/soap/http"/>
<operation name="FlickrRequest">
<soap:operation soapAction="FlickrRequest"/>
<input>
<soap:body use="encoded"
encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"
namespace="urn:flickr"/>
</input>
<output>
<soap:body use="encoded"
encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"
namespace="urn:flickr"/>
</output>
</operation>
</binding>
<service name="Flickr">
<documentation>WSDL File for Flickr</documentation>
<port name="Flickr_Port" binding="tns:Flickr_Binding">
<soap:address location="http://api.flickr.com/services/soap/"/>
</port>
</service>
</definitions>


which, using XML-Spy gets me a SOAP body of

<SOAP-ENV:Envelope
xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:xsd="http://www.w3.org/2001/XMLSchema"
SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
<SOAP-ENV:Body>
<m:FlickrRequest xmlns:m="urn:flickr">
<method xsi:type="xsd:string">String</method>
<api_key xsi:type="xsd:string">String</api_key>
</m:FlickrRequest>
</SOAP-ENV:Body>
</SOAP-ENV:Envelope>

I then have to fill out the method -> flickr.test.echo and the api_key
-> e81ef8102a5160154ef4662adcc9046b -- and that gets me what I want
-- sorta.

The problem is that 1) I shouldn't have to fill out the method name --
that's what I want the WSDL to have to generate and 2) I can't see a
way to add other Flickr methods to the same WSDL file because they all
invoke a FlickrRequest method -- and pass the real method name as a
method parameter. I'm getting the sense that if Flickr used the
following SOAP body instead;

<?xml version='1.0' encoding='UTF-8'?>
<s:Envelope xmlns:s='http://www.w3.org/2003/05/soap-envelope'
xmlns:xsi='http://www.w3.org/1999/XMLSchema-instance'
xmlns:xsd='http://www.w3.org/1999/XMLSchema'>
<s:Body>
<x:flickr.test.echo xmlns:x='urn:flickr'>
<api_key>e81ef8102a5160154ef4662adcc9046b</api_key>
</x:flickr.test.echo>
</s:Body>
</s:Envelope>

I'd be able to generate the WSDL w/o any problem.

Do you any way around this problem? I could generate one WSDL file
for each Flickr method -- but that doesn't seem quite right either.

Thanks,
-Raymond