Why would same SOAP request work in one Flex project and not another?

Question

This is a pretty odd situation I have here. I have used a piece of code to interact with a backend SOAP service for several months - it works fine. I tried it out in a different project (first as an swc library and then just by cutting and pasting) and it just doesnt work.

If I try the exact same code in the original flex project, connecting to the same backend service, everything works fine. In the new project, I can call operations that take simple document-literal wrappers as params (they have no real parameters) - but if the operation has a complex parameter inside the document literal wrapper - fail on this new project. Here is a sample that would fail:

var service:WebService = new WebService();
service.wsdl = wsdlURL;
var operation:AbstractOperation = service.getOperation( "addNewUser" );

var param:XML = <AddNewUserRequest/>
param.setNamespace( myNameSpace );

param.user.username( username );
param.user.email( email );

operation.send( param );

And here is a sample that would work in the new project:

var service:WebService = new WebService();
service.wsdl = wsdlURL;
var operation:AbstractOperation = service.getOperation( "getUsers" );

var param:XML = <GetUsersRequest/>
param.setNamespace( myNameSpace );

operation.send( param );

Here are some things that I have done to try an track this one down:

-Examined the posts in firebug from both projects and can not see a difference (meaning that the code appears to generate the exact same SOAP request in both projects (as one expects) -I have verified that the requests should work using SOAPui to directly query the web service

The back end service is an Apache CXF webservice and here is a sample of the error it generates:

org.apache.cxf.interceptor.Fault: Found element {http://www.w3.org/2001/XMLSchema}user but could not find matching RPC/Literal part

Everything I know leads me to believe that user should be in the http://www.w3.org/2001/XMLSchema namespace - and honestly - I believe the key here is that the code works in one project but not in the other. Could it be an XML setting? One of the static ones like ignoreWhitespace? I have played with changing those around - with no luck.

Any ideas at all? This is driving me crazy!!!

UPDATE:

I have narrowed it down to this: the new project creates a header like this:

<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"&gt;

and the one that works creates this:

<SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"&gt;

Why the difference on the exact same version of flex & flex builder? The one that works is obviously correct (xmlns:xsd="http://www.w3.org/2001/XMLSchema") - the web service is correct to reject a request that puts everything in the request in the xsd namespace.

Answer 1

You're hardcoding your request as XML, and I assume your custom namespace doesn't have a prefix, so it's conflicting with the default namespace for XSD declared in your header. Why you're getting different headers I don't know, but you're probably compiling your project with different versions of the SDK.

A few things to try:

• Make sure you're using the sake SDK to compile both projects (the latest you can get away with, as bugfixes to the SOAP stack go into almost every release)

• Set an explicit prefix for your namespace, using:

  var myNameSpace:NameSpace = new NameSpace("my","http://something.com/foo/ns");

• Instead of building an XML request, build it as plain AS3 Objects, like so:

  var request:Object = {GetUsersRequest: {parm1: foo, parm2:bar }};

  ...and let Flex do all the encoding for you. A whole bunch of people (myself included) have put countless hours into making the Flex SOAP stack work well with AS3 objects instead of hand-crafted XML requests, why not let the SDK do the work of constructing your request for you?

Answer 2

The reason it's adding xmlns="http://www.w3.org/2001/XMLSchema" to the SOAP Envelope instead of xmlns:xsd="http://www.w3.org/2001/XMLSchema" is because that's how it's defined in rpc.xml.SchemaConstants class. At some point in the broken project, you have imported an xsd into the rpc.xml.SchemaManager class that defines xmlns="http://www.w3.org/2001/XMLSchema", which overrides the default definition in SchemaConstants.

Try checking all of the xsds that you are using and make sure that they don't contain xmlns="http://www.w3.org/2001/XMLSchema".