xml info to php (webservice)

我使用php从Web服务获取数据。我有这个代码：

try 
{ 
    $wsdl_url = 'https://xxx';
    $client = new SOAPClient($wsdl_url); 
    $params = array(
        'Code' => '1111', 
        'Name' => 'Marcos', 
        'Client' => '009462'
    );
    $return = $client->GetData($params); 
    print_r($return); 
} 
catch (Exception $e) 
{ 
    echo "Exception occured: " . $e;
}

现在，我有了一个带参数的xml。示例：

<san:GetData>
<san:objData xsi:type="PricesData" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns="http://">
    <san:Code>7</san:Code>
    <san:Client>999999</san:Client>
    <san:Data>
        <san:Fact>CF</san:Fact>
        <san:Fact2>CF</san:Fact2>
    </san:Data>
    <san:DataProduct>
        <san:Code>0202</san:Code>
        <san:PersonalData>
          <san:Name>00030</san:Name>
          <san:Company>00045</san:Company>
        </san:PersonalData>
    </san:DataProduct>
</san:objData>

如何将这些参数传递给php数组？因为它把数据分为"类别"，我不知道如何操作它们。

谢谢。