PHP Betfair Free Access API, how to build APIRequestHeader & call any method?

Question

I am trying to write a simple PHP client to get some data from Betfair through the Free Access API http://bdp.betfair.com/?option=com_content&task=view&id=33&Itemid=62

I can login & get a session token, this way

$wsdl = 'https://api.betfair.com/global/v3/BFGlobalService.wsdl';
$soapClient = new SoapClient($wsdl); 
try {
    $ap_param = array(
        'request' => 
            array(
                'username' => 'my_username',
                'password' => 'my_password',
                'productId' => '82',    
                'ipAddress' => '',
                'locationId' => '',
                'vendorSoftwareId' => '',
            ),
        );  
    $response = $soapClient->__call("login", array($ap_param));
...

$response is an object containing the sessionToken param

But after several tries I am afraid I am sending the APIRequestHeader param (http://bdp.betfair.com/docs/) malformed, cause the response to any call (getAllEventTypes, for instance) is always returning the same: NO_SESSION

One try...

$ap_param = array(
    'request' => 
        array(
            'header' => array(
                'session_token' => $response->Result->header->sessionToken,
                'clientStamp' => 0,
            ),          
        ),
    );      

Another try...

$ap_param = array(
    'request' => 
        array(
            'session_token' => $response->Result->header->sessionToken,
            'clientStamp' => 0,
        ),
    ); 

And lot of other tries... but

$response = $soapClient->__call("getAllEventTypes", array($ap_param));

$response is always the same

stdClass Object
(
    [Result] => stdClass Object
        (
            [header] => stdClass Object
                (
                    [errorCode] => NO_SESSION
                    [minorErrorCode] => 
                    [sessionToken] => 
                    [timestamp] => 2013-11-09T08:41:01.015Z
                )

            [eventTypeItems] => 
            [minorErrorCode] => 
            [errorCode] => API_ERROR
        )

)

Someone here has faced the same problem?

Answer 1

Stupid typo error there...

session_token should be sessionToken

$ap_param = array(
    'request' => 
        array(
            'header' => array(
                'sessionToken' => $response->Result->header->sessionToken,
                'clientStamp' => 0,
            ),          
        ),
    );