session.php

<?php
// include init.in, which will call $GLOBALS['SQ_SYSTEM']->init() and start a session
require_once '../../include/init.inc';

$site_network_id = array_get_index($_GET, 'site_network', '0');
$site_network = null;
$primary_url = '';
$session_handler = $GLOBALS['SQ_SYSTEM']->getSessionHandlerClassName();

if ($site_network_id) {
    $site_network = &$GLOBALS['SQ_SYSTEM']->am->getAsset($site_network_id);
    if (!is_null($site_network)) {
        $primary_url = $site_network->getPrimaryURL();
    }
}
if ($primary_url == sq_web_path('root_url')) {
    // if the actual script execution is happening in the primary
    // url, we want to update the time to persuade the overriding
    // of the secondary session files
    if (isset($_GET['in_primary']) && $_GET['in_primary']) {
        $_SESSION['SQ_SESSION_TIMESTAMP'] = time();
        exit();
    }

    // see design.inc and pre_session.php
    // on how we call this function when we move from one site to another
    echo 'var SESSIONID = "'.session_id().'";';
    ?>
    function start_session_handler(url) {
        JsHttpConnector.submitRequest(url + '&sessionid=' + SESSIONID);
    }
    <?php

} else {
    
    if (!isset($_GET['sessionid']) || !preg_match('/^[a-z0-9]+$/i', $_GET['sessionid'])) {
        // something is definately wrong
        trigger_localised_error('SYS0013', E_USER_ERROR);
    }
    if (is_null($site_network)) {
        trigger_localised_error('SYS0014', E_USER_ERROR);
    }
    
    $session_handler_instance = new $session_handler();
    $session_handler_instance->syncSession($_GET['sessionid']);

}//end if
?>