I used to be a fan of using nusoap with PHP3/4 (i.e. back when PHP didn t have a built in SOAP client) but with PHP5 s SOAP Client I find I don t have any need for nusoap these days.

An advantage PHP5 s built in SOAP client is that it s much cleaner and simplier to implement and so mention it as it might be helpful to you (I know some choose to use nusoap instead, but a lot of people apparently just aren t aware it s there in PHP5 as a lot of "HOWTO" guides are out of date and neglect to mention it).

Example usage:

ini_set("soap.wsdl_cache_enabled", "1"); // Set to zero to avoid caching WSDL
$soapClient = new SoapClient( http://www.example.com/webservices/HelloWorldService/?wsdl");     
$result = $soapClient->HelloWorldMethod(array( string  => "hello!"));    
print_r($result);

On a note regarding service types:

When it comes to a SOAP service, ideally you want to implement a Document/Literal service, rather than an RPC/Encoded service, as RPC/Encoded is a difficult format to work with and for that reason has been deprecated by the WS-I in favour of Document/Literal (which is both much easier to work with and more logical in design).

To start with, you might want to try implementing a client against an existing service if you can - that way you know it s at least working properly, which might save you a few headaches.

Unfortunately - while it s excellent at consuming them - PHP doesn t have particularly great support for serving Document/Literal services. There is at least one third party nusoap-like library for this IIRC, but it didn t quite cut it for me.

(If any of this is outdated, corrections welcome.)

This thread may help you, especially answer #9 and #10.

Just in case some googlers find this...

I edited the php.ini as ccheneson suggested and this code worked just fine, even on the same dev server.

Client - based in a Drupal page in PHP mode:

<?php
# URL for the service WSDL
ini_set("soap.wsdl_cache_enabled", "0"); // Set to zero to avoid caching WSDL
try {
    // Get a service proxy from the WSDL
    $proxy = new SoapClient( http://testing.domain.com/soap.php?wsdl );
    global $user;
    if (is_array($user->roles) && in_array( group1 , array_values($user->roles))) {
        // User is logged in and is in the usergroup, perform login
        $id = $user->uid;
        $key = 1234; 
        $hashgenerator = $key . "xyz" . $id . "randomstringhere";
        $hash = sha1($hashgenerator);
        // Call a method on the service via the proxy
        $result = $proxy->handshake($id, $key, $hash);
        if ($hash==$result) {
            //Send all user details
            profile_load_profile($user);
            $email = $user->mail;
            $fname = $user->{profile_firstname};
            $lname = $user->{profile_lastname};
            $phone = $user->{profile_phone};
            $fax = $user->{profile_fax};
            $dept = "Speakers";
            $role = "Speakers";
            //Send request
            $authresult = $proxy->authlogin($id, $email, $fname, $lname, $phone, $fax, $authgroup);
            if ($authresult== ok ) {
                //Logged in, show them the page
                $_SESSION[ loggedin ] = 1;
            } else {
                echo "Error 3";         
            }
        } else {
            echo "Error 2"; 
        }
    } else {
        echo "Error 1"; 
    }
} catch(SoapFault $ex) {
    echo  Error:  ;
    if ($ex->getMessage() !=   ) {
        echo $ex->getMessage();
    } else {
        echo $ex . "
";
    }
}
?>

Service:

<?php
//----------------------------------//
// This file is a dummy service It obviously does nothing with the data, but i needed it to build my client scripts and so it might give you a hand returning the correct strings.
//----------------------------------//

// Pull in the NuSOAP code
require_once( nusoap/nusoap.php );
// Create the server instance
$server = new soap_server();
// Initialize WSDL support
$server->configureWSDL( WDSL ,  urn:WDSL );
// Register the methods to expose
$server->register( handshake ,              // method name
    array( id  =>  xsd:string , 
           key  =>  xsd:string ,
           hash  =>  xsd:string ),          
    array( return  =>  xsd:string ),        // output parameters
     urn:WDSL ,                             // namespace
     urn:WDSL#_handshake ,                  // soapaction
     rpc ,                                  // style
     encoded ,                              // use
     Initial handshake                      // documentation
);
$server->register( authlogin ,              // method name
    array( id  =>  xsd:string ,             // User ID
           email  =>  xsd:string ,          // User email address
           fname  =>  xsd:string ,          // User first name
           lname  =>  xsd:string ,          // User last name
           phone  =>  xsd:string ,          // User phone
           fax  =>  xsd:string ,            // User fax 
           dept  =>  xsd:string ,           // SB department
           role  =>  xsd:string ),          // SB role  
    array( return  =>  xsd:string ),        // output parameters
     urn:WDSL ,                             // namespace
     urn:WDSL#authlogin ,                   // soapaction
     rpc ,                                  // style
     encoded ,                              // use
     Authentication of a user               // documentation
);
// Define the method as a PHP function
function slidebank_handshake($uid, $key, $hash) {
    //returns the same hash string for confirmation. No need to pass UID again.
    $hashgenerator = $key . "xyz" . $uid . "randomstringhere";  
    $hash = sha1($hashgenerator);
    return $hash;
}
// Define the method as a PHP function
function slidebank_authlogin($id, $email, $fname, $lname, $phone, $fax, $dept, $role) {
    //logic to log user in and capture details etc
    return  ok ; //options = ok or fail
}
// Use the request to (try to) invoke the service
$HTTP_RAW_POST_DATA = isset($HTTP_RAW_POST_DATA) ? $HTTP_RAW_POST_DATA :   ;
$server->service($HTTP_RAW_POST_DATA);
?>