settings.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/>.

/**
 * OneSignal configuration page
 *
 * @package    message_onesignal
 * @copyright  2012 Jerome Mouneyrac, 2014 Juan Leyva
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
defined('MOODLE_INTERNAL') || die;

if ($ADMIN->fulltree) {
    $settings->add(new admin_setting_configtext('onesignalappid',
                    get_string('onesignalappid', 'message_onesignal'),
                    get_string('configonesignalappid', 'message_onesignal'), '', PARAM_ALPHANUMEXT));

                    $settings->add(new admin_setting_configtext('onesignalrestkey',
                                    get_string('onesignalrestkey', 'message_onesignal'),
                                    get_string('onesignalrestkey', 'message_onesignal'), '', PARAM_ALPHANUMEXT));
}