PEAR::SOAP and PHP-SOAP supports binding WSDL files to the server objects. This allows for much easier server design, and makes using PHP objects as SOAP servers possible without any modifications. Binding the server to a WSDL allows the WSDL to define types and interfaces for any SOAP requests made against the server. Serialization of data will also be easier for the developer.

PHP-SOAP also has an option to persist server objects allowing for more robust server-side applications using SOAP.

WSDL based SOAP Server

<?php

class SOAP_Example_Server {
    var $name = NULL;
    
    function setName($inputString)
    {
        $this->name = $inputString;
        return true;
    }

    function getName()
    {
        return $this->name;
    }
}

$server = new SoapServer('urn:SOAP_Example_Server');
$server->bind('SOAP_Example_Server.wsdl');
$server->setClass('MyClass');

# tell the server to use PHP's session capabilities
# to persist the object
$server->setPersistence(SOAP_PERSISTENCE_SESSION);

$server->handle();
?>
WSDL based SOAP Client

<?
$client = SoapObject('http://localhost/SOAP_Example_Server.wsdl');

# These two function calls are seperate HTTP Requests
$client->setName('Brad Lafountain');
$name = $client->getName();
?>