如何在肥皂呼叫之前获取肥皂请求？

Question

我创建了一个这样的数组

"AnonymousTraveler"=>array(
        "ObjectKey" => "PAX1",
        "PTC"=>array(
            "_" => 'ADT',
            "Quantity" => "1"
            ),
        )

我的XML必须像这样

<AnonymousTraveler ObjectKey="PAX1">
    <PTC Quantity="1">ADT</PTC>
</AnonymousTraveler>

在调用soap之前，我需要检查XML格式。所以我创建了这样的格式

class DummySoapClient extends SoapClient {
    function __construct($wsdl, $options) {
        parent::__construct($wsdl, $options);
    }
    function __doRequest($request, $location, $action, $version, $one_way = 0) {
        print_r($request)."<br>";
        exit;
        return $request;
    }
}

$client = new DummySoapClient($wsdl,array("exceptions" => 0
    ,'soap_version' => SOAP_1_1
    ,"cache_wsdl" => WSDL_CACHE_NONE
    , 'trace' => true
    ,"features" => SOAP_SINGLE_ELEMENT_ARRAYS)); 

我的问题现在不是__doRequest ..我不是没有问题。任何人都可以为此提供一些解决方案。谢谢你的进步。