How to post SOAP Request from PHP

Question

Anyone know how can I post a SOAP Request from PHP?

Answer 1

In my experience, it's not quite that simple. The built-in PHP SOAP client didn't work with the .NET-based SOAP server we had to use. It complained about an invalid schema definition. Even though .NET client worked with that server just fine. By the way, let me claim that SOAP interoperability is a myth.

The next step was NuSOAP. This worked for quite a while. By the way, for God's sake, don't forget to cache WSDL! But even with WSDL cached users complained the damn thing is slow.

Then, we decided to go bare HTTP, assembling the requests and reading the responses with SimpleXMLElemnt, like this:

$request_info = array();

$full_response = @http_post_data(
    'http://example.com/OTA_WS.asmx',
    $REQUEST_BODY,
    array(
        'headers' => array(
            'Content-Type' => 'text/xml; charset=UTF-8',
            'SOAPAction'   => 'HotelAvail',
        ),
        'timeout' => 60,

    ),
    $request_info
);

$response_xml = new SimpleXMLElement(strstr($full_response, '<?xml'));

foreach ($response_xml->xpath('//@HotelName') as $HotelName) {
    echo strval($HotelName) . "\n";
}

Note that in PHP 5.2 you'll need pecl_http, as far as (surprise-surpise!) there's no HTTP client built in.

Going to bare HTTP gained us over 30% in SOAP request times. And from then on we redirect all the performance complains to the server guys.

In the end, I'd recommend this latter approach, and not because of the performance. I think that, in general, in a dynamic language like PHP there's no benefit from all that WSDL/type-control. You don't need a fancy library to read and write XML, with all that stubs generation and dynamic proxies. Your language is already dynamic, and SimpleXMLElement works just fine, and is so easy to use. Also, you'll have less code, which is always good.