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SOAP::WSDL appears to have been designed for this problem. Soap::Lite's POD says that it doesn't fully support WSDL. Something like ...

 .
 .
 .

  my $soap=SOAP::WSDL->new();
  $soap->wsdl($self->{'data'}->{'namespace'});
  $soap->proxy($self->{'data'}->{'proxy'} );

  $soap->wsdlinit;

  # This part is the big rebuild, as you no longer have
  # to hand-roll your XML ... good thing, too

  my $som=$soap->call( $method ,  
                   name => 'value' ,
                   name => 'value'  );
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Thank you for this recommendation. SOAP::WSDL does, in fact, seem to have been designed for this problem.

I was able to get the simple methods to work using the WSDL, which saves some grief in terms of rolling my own XML. Unfortunately, again, I got hung up on the complex types, and the error messages produced aren't very elaborate. It seems that when I call a method that involves complex types, the WSDL is not able to resolve the definitions. I suspect this is because of a corporate firewall, but I'm not sure.

Here's the code I have so far (somewhat sanitized):

#!/usr/local/bin/perl

use strict;
use warnings;
use SOAP::WSDL +trace => 'all';

use Data::Dumper;

Main: {
  my $soap=SOAP::WSDL->new( wsdl => 'http://some_ip/wsdl/myServiceName
+.wsdl' );

  $soap->proxy('http://some_ip:port/some/path/myServiceLocation');

  $soap->servicename('myServiceName');
 
  $soap->wsdlinit( caching => 1);

  my $response;
  
  eval { # this one worked with no troubles
    $response = $soap->call( 'queryItem' ,  
      id => 'blah' ,
      pwd => 'bleh',
      itemId => '9015');
  };

  if ($@) {
    print "SOAP call failed: $@\n";
    exit;
  }
      
  eval { # this one fails with the "error processing WSDL" message
    $response = SOAP_add_Item($soap);
  };

  if ($@) {
    print "SOAP call failed: $@\n";
    exit;
  }
    
  if ($response->fault) { 
    print Dumper($response->faultdetail), "\n"; 
  }
  else {
    my $body = $response->result; 
    unless ($body == 0) {
      print "SOAP Message: ", Dumper($body);
    }
  }
}


sub SOAP_add_Item {
    my $soap = shift;
    my $response = $soap->call('addItem',
   'id' => 'blah',
   'pwd' => 'bleh',
   'itemId' => '1234',
   'itemName' => 'Test Item',
   'Ranges' => [
     { 'min' => '8605118310',
       'max' => '8605118319' } ] );
   
  return $response;
}
    
#   'Ranges' => [
#     bless( {
#       'min' => '8605118310',
#       'max' => '8605118319'
#     }, 'SoapTypeRange' ) ] );
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I've tried the complex 'Ranges' type with and without the reference to the type 'SoapTypeRange', but in neither case does it seem to be able to resolve the type.

Instead, I get this message:

SOAP call failed: Error processing WSDL: './/xsd:element' not found at
+ /usr/local/lib/perl5/site_perl/5.8.6/SOAP/WSDL.pm line 504.
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That line in WSDL.pm seems to be in the context of attempting to resolve definitions for complex types. The relevant lines in the WSDL seem to be:

<wsdl:definitions name="myServiceName" 
targetNamespace="http://some_ip/wsdl/myServiceName/" 
xmlns:tns="http://some_ip/wsdl/myServiceName/" 
xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:soap12="http:
+//schemas.xmlsoap.org/wsdl/soap12/" 
xmlns:http="http://schemas.xmlsoap.org/wsdl/http/" xmlns:mime="http://
+schemas.xmlsoap.org/wsdl/mime/" 
xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/" xmlns:wsdl="
+http://schemas.xmlsoap.org/wsdl/" 
<wsdl:types> 
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
targetNamespace="http://some_ip/package/various.other.soap.types 
/"> 
<xsd:import namespace="http://schemas.xmlsoap.org/soap/encoding/" /> 
<xsd:complexType name="SoapTypeRange"> 
<xsd:all> 
<xsd:element name="min" type="xsd:long" /> 
<xsd:element name="max" type="xsd:long" /> 
</xsd:all> 
</xsd:complexType> 
<xsd:complexType name="ArrayOfSoapTypeRange"> 
<xsd:complexContent> 
<xsd:restriction base="soapenc:Array"> 
<xsd:attribute ref="soapenc:arrayType" wsdl:arrayType="n11:SoapTypeRan
+ge[]" /> 
</xsd:restriction> 
</xsd:complexContent> 
</xsd:complexType> 
</xsd:schema> 
</wsdl:types>
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I'm stumped. If I can't get outside the firewall to resolve the complex type definitions, then how can I build a workable SOAP call to this service? Any additional thoughts are very welcome.


No good deed goes unpunished. -- (attributed to) Oscar Wilde

One of the tools available on the soapclient.com site may be able to help in debugging. I've only used the Generic SOAP Client in the past, but it proved very handy indeed for pointing out that my initial code was a steaming pile of... ;-)

Hope that helps.

Should I push back to the vendor and require them to respond with decent error messages if my XML is badly formed or typed, or is their position reasonable and I simply need to figure out how to validate my own messages?

Most of the people who write Web Services have no idea about interoperability -- they're using toolkits to generate the service, and couldn't change the error messages if they even wanted to.

Odds are, the stack traces they've giving back, besides being a potential security problem, actually have some clue as to where the problem is ... but you didn't have that, so I have no idea. If you can find out what SOAP toolkit they're using, you might be able to find some sort of support forum for it, and find some hints as to what the problem is.

As for pre-validating the XML -- the bulk of WSDL is just XML Schema, so you might be able to use an XML Schema validator for the payload.

Dealing with the 'impedence errors' that come from different SOAP toolkits is a royal pain -- make sure you're casting each element as a SOAP::Data object, or use a custom serializer -- the default SOAP::Lite serializer makes a lot of assumptions that can be false (eg, '1234' is an integer ... even though it's supposed to be a string in the WSDL).