Proyectos de Subversion Moodle

<?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/>.

/**

 * Helper class.

 *

 * @package    quizaccess_seb

 * @author     Dmitrii Metelkin <dmitriim@catalyst-au.net>

 * @copyright  2020 Catalyst IT

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace quizaccess_seb;

use CFPropertyList\CFPropertyList;

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

/**

 * Helper class.

 *

 * @copyright  2020 Catalyst IT

 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

class helper {

    /**

     * Get a filler icon for display in the actions column of a table.

     *

     * @param string $url The URL for the icon.

     * @param string $icon The icon identifier.

     * @param string $alt The alt text for the icon.

     * @param string $iconcomponent The icon component.

     * @param array $options Display options.

     * @return string

     */

    public static function format_icon_link($url, $icon, $alt, $iconcomponent = 'moodle', $options = []) {

        global $OUTPUT;

        return $OUTPUT->action_icon(

            $url,

            new \pix_icon($icon, $alt, $iconcomponent, [

                'title' => $alt,

            ]),

            null,

            $options

        );

    }

    /**

     * Validate seb config string.

     *

     * @param string $sebconfig

     * @return bool

     */

    public static function is_valid_seb_config(string $sebconfig): bool {

        $result = true;

        set_error_handler(function($errno, $errstr, $errfile, $errline ){

            throw new \ErrorException($errstr, $errno, 0, $errfile, $errline);

        });

        $plist = new CFPropertyList();

        try {

            $plist->parse($sebconfig);

        } catch (\ErrorException $e) {

            $result = false;

        } catch (\Exception $e) {

            $result = false;

        }

        restore_error_handler();

        return $result;

    }

    /**

     * A helper function to get a list of seb config file headers.

     *

     * @param int|null $expiretime  Unix timestamp

     * @return array

     */

    public static function get_seb_file_headers(int $expiretime = null): array {

        if (is_null($expiretime)) {

            $expiretime = time();

        }

        $headers = [];

        $headers[] = 'Cache-Control: private, max-age=1, no-transform';

        $headers[] = 'Expires: '. gmdate('D, d M Y H:i:s', $expiretime) .' GMT';

        $headers[] = 'Pragma: no-cache';

        $headers[] = 'Content-Disposition: attachment; filename=config.seb';

        $headers[] = 'Content-Type: application/seb';

        return $headers;

    }

    /**

     * Get seb config content for a particular quiz. This method checks caps.

     *

     * @param string $cmid The course module ID for a quiz with config.

     * @return string SEB config string.

     */

    public static function get_seb_config_content(string $cmid): string {

        // Try and get the course module.

        $cm = get_coursemodule_from_id('quiz', $cmid, 0, false, MUST_EXIST);

        // Make sure the user is logged in and has access to the module.

        require_login($cm->course, false, $cm);

        // Retrieve the config for quiz.

        $config = seb_quiz_settings::get_config_by_quiz_id($cm->instance);

        if (empty($config)) {

            throw new \moodle_exception('noconfigfound', 'quizaccess_seb', '', $cm->id);

        }

        return $config;

    }

    /**

     * Serve a file to browser for download.

     *

     * @param string $contents Contents of file.

     */

    public static function send_seb_config_file(string $contents) {

        // We can now send the file back to the browser.

        foreach (self::get_seb_file_headers() as $header) {

            header($header);

        }

        echo($contents);

    }

}