sessionkeepalive_ajax.php

<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Ensure that session is kept alive.
 *
 * @copyright 2014 Andrew Nicols
 * @package   core
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

define('AJAX_SCRIPT', true);
require_once(__DIR__ . '/../config.php');

// Require the session key - want to make sure that this isn't called
// maliciously to keep a session alive longer than intended.
if (!confirm_sesskey()) {
    header('HTTP/1.1 403 Forbidden');
    print_error('invalidsesskey');
}

// Update the session.
\core\session\manager::touch_session(session_id());