auth.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/>.

/**
 * Authentication Development Tools
 * Uses to developers and main admins.
 *
 * @package    auth_dev
 * @author     Carlos Escobedo <http://www.twitter.com/carlosagile>)
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

defined('MOODLE_INTERNAL') || die();

require_once($CFG->libdir.'/authlib.php');

/**
 * Authentication Development Tools plugin.
 *
 * @package    auth
 * @subpackage dev
 * @author     Carlos Escobedo <http://www.twitter.com/carlosagile>)
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class auth_plugin_dev extends auth_plugin_base {
    /**
    * The name of the component. Used by the configuration.
    */
    const COMPONENT_NAME = 'auth_dev';

    /**
     * Constructor.
     */
    public function __construct() {
        $this->authtype = 'dev';
        $this->config = get_config(self::COMPONENT_NAME);
    }

    /**
     * Prints a form for configuring this authentication plugin.
     *
     * This function is called from admin/auth.php, and outputs a full page with
     * a form for configuring this plugin.
     *
     * @param array $config An object containing all the data for this page.
     * @param string $error
     * @param array $user_fields
     * @return void
     */
    function config_form($config, $err, $user_fields) {
        global $CFG;
        
        if (!isset($config->enablelogouturl)) {
            $config->enablelogouturl = 'off';
        }
        if (!isset($config->logouturl)) {
            $config->logouturl = '';
        }
        
        include 'config.html';
    }

    /**
     * Processes and stores configuration data for this authentication plugin.
     *
     * @param stdClass $config
     * @return void
     */
    function process_config($config) {
        // Set to defaults if undefined.
        if (!isset($config->enablelogouturl)) {
            $config->enablelogouturl = 'off';
        }
        if (!isset($config->logouturl)) {
            $config->logouturl = '';
        }

        // Save settings.
        set_config('enablelogouturl', $config->enablelogouturl, self::COMPONENT_NAME);
        set_config('logouturl', $config->logouturl, self::COMPONENT_NAME);

        return true;
    }


    public function prelogout_hook() {
        global $CFG, $SESSION, $USER;

        if (\core\session\manager::is_loggedinas()) {
            $id = optional_param('id', 0, PARAM_INT);
            // IF ID==0 then logout request, notthing to do.
            if ($id) {
                $realuser = \core\session\manager::get_realuser();
                // Check is siteadmin. 
                // Only siteadmins can use this tool.
                if (is_siteadmin($realuser)) {
                    complete_user_login($realuser);
                    $SESSION->wantsurl = "$CFG->wwwroot/course/view.php?id=".$id;
                    // Logout Redirection.
                    if (!empty($this->config->logouturl)) {
                        redirect($this->config->logouturl);
                    } else {
                        redirect($SESSION->wantsurl);
                    }   
                }
            }
        } 
    }

    /**
     * Hook for overriding behaviour of logout page.
     * This method is called from login/logout.php page for all enabled auth plugins.
     *
     * @global string
     */
    function logoutpage_hook() {
        global $redirect; // can be used to override redirect after logout
       
        if (isset($this->config->enablelogouturl) and $this->config->enablelogouturl == 'on') {
            if (!empty($this->config->logouturl)) {
                $redirect = $this->config->logouturl;
            }
        }     
    }
}