header.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/>.

/**
 * Header part for each view file in the module
 *
 * @package     mod_groupformation
 * @author      Eduard Gallwas, Johannes Konert, Rene Roepke, Nora Wester, Ahmed Zukic
 * @copyright   2015 MoodlePeers
 * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
require_once('../../config.php');

require_once('lib.php');
require_once('locallib.php');

// Reads URL params.
$id = required_param('id', PARAM_INT);
$doshow = optional_param('do_show', 'view', PARAM_TEXT);

$urlparams = ['id' => $id, 'do_show' => $doshow];

// Determines instances of course, course module and groupformation.
list ($course, $cm, $groupformation) = groupformation_determine_instance($id);

// Requires user to login if not already logged in.
require_login($course, true, $cm);

// Get useful stuff.
$context = context_module::instance($cm->id);
$userid = $USER->id;