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/>.

namespace local_listcoursefiles;

/**

 * Class course_file

 * @package local_listcoursefiles

 * @copyright  2017 Martin Gauk (@innoCampus, TU Berlin)

 * @author     Jeremy FitzPatrick

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

 */

class course_file {

    /**

     * @var \stdClass

     */

    protected $file;

    /**

     * @var int

     */

    protected $courseid = 0;

    /* Properties used by the template. */

    /**

     * @var int

     */

    public $fileid = 0;

    /**

     * @var string

     */

    public $filelicense = '';

    /**

     * @var string Friendly readable size of the file (MB or kB as appropriate)

     */

    public $filesize = '';

    /**

     * @var string

     */

    public $filetype = '';

    /**

     * @var string The name of the person who uploaded the file.

     */

    public $fileuploader = '';

    /**

     * @var bool Is the license expired?

     */

    public $fileexpired = false;

    /**

     * @var false|string

     */

    public $fileurl = false;

    /**

     * @var string

     */

    public $filename = '';

    /**

     * @var false|string A link to the page where the file is used.

     */

    public $filecomponenturl = false;

    /**

     * @var string

     */

    public $filecomponent;

    /**

     * @var string|false A link to the page with the editor where the file was added.

     */

    public $fileediturl = false;

    /**

     * @var string A message stating if the file is used or unknown.

     */

    public $fileused;

    /**

     * Creates an object of this class or an appropriate subclass.

     * @param \stdClass $file

     * @return course_file

     * @throws \coding_exception

     * @throws \dml_exception

     * @throws \moodle_exception

     */

    public static function create(\stdClass $file): course_file {

        $classname = '\local_listcoursefiles\components\\' . $file->component;

        if (class_exists($classname)) {

            return new $classname($file);

        }

        return new course_file($file);

    }

    /**

     * course_file constructor.

     * @param \stdClass $file

     * @throws \coding_exception

     * @throws \dml_exception

     * @throws \moodle_exception

     */

    public function __construct(\stdClass $file) {

        global $COURSE;

        $this->courseid = $COURSE->id;

        $this->file = $file;

        $this->filelicense = licences::get_license_name_color($file->license ?? '');

        $this->fileid = $file->id;

        $this->filesize = display_size($file->filesize);

        $this->filetype = mimetypes::get_file_type_translation($file->mimetype);

        $this->fileuploader = fullname($file);

        $this->fileexpired = !$this->check_mimetype_license_expiry_date();

        $fileurl = $this->get_file_download_url();

        $this->fileurl = ($fileurl) ? $fileurl->out() : false;

        $this->filename = $this->get_displayed_filename();

        $componenturl = $this->get_component_url();

        $this->filecomponenturl = ($componenturl) ? $componenturl->out() : false;

        $this->filecomponent = course_files::get_component_translation($file->component);

        $isused = $this->is_file_used();

        if ($isused === true) {

            $this->fileused = get_string('yes', 'core');

        } else if ($isused === false) {

            $this->fileused = get_string('no', 'core');

        } else {

            $this->fileused = get_string('nottested', 'local_listcoursefiles');

        }

        $editurl = $this->get_edit_url();

        $this->fileediturl = ($editurl) ? $editurl->out(false) : false;

    }

    /**

     * Getter for filename

     * @return string

     */

    protected function get_displayed_filename(): string {

        return $this->file->filename;

    }

    /**

     * Check if a file with a specific license has expired.

     *

     * This checks if a file has been expired because:

     *  - it is a document (has a particular mimetype),

     *  - has been provided under a specific license

     *  - and the expiry date is exceed (in respect of the course start date and the file creation time).

     *

     * The following settings need to be defined in the config.php:

     *   array $CFG->fileexpirylicenses which licenses (shortnames) expire

     *   int $CFG->fileexpirydate when do files expire (unix time)

     *   array $CFG->filemimetypes['document'] mime types of documents

     *

     * These adjustments were made by Technische Universität Berlin in order to conform to § 52a UrhG.

     *

     * @return boolean whether file is allowed to be delivered to students

     */

    protected function check_mimetype_license_expiry_date(): bool {

        global $CFG, $COURSE;

        // Check if enabled/configured.

        if (!isset($CFG->fileexpirydate, $CFG->fileexpirylicenses, $CFG->filemimetypes['document'])) {

            return true;

        }

        if (in_array($this->file->license, $CFG->fileexpirylicenses)) {

            $isdoc = false;

            $fmimetype = $this->file->mimetype;

            foreach ($CFG->filemimetypes['document'] as $mime) {

                if ($mime === $fmimetype || (substr($mime, -1) === '%' && strncmp($mime, $fmimetype, strlen($mime) - 1) === 0)) {

                    $isdoc = true;

                    break;

                }

            }

            $coursestart = $COURSE->startdate ?? 0;

            if ($isdoc && $CFG->fileexpirydate > max($coursestart, $this->file->timecreated)) {

                return false;

            }

        }

        return true;

    }

    /**

     * Try to get the download url for a file.

     *

     * @return null|\moodle_url

     * @throws \moodle_exception

     */

    protected function get_file_download_url(): ?\moodle_url {

        if ($this->file->filearea == 'intro') {

            return $this->get_standard_file_download_url();

        }

        return null;

    }

    /**

     * Get the standard download url for a file.

     *

     * Most pluginfile urls are constructed the same way.

     *

     * @param bool $insertitemid

     * @return \moodle_url

     * @throws \moodle_exception

     */

    protected function get_standard_file_download_url(bool $insertitemid = true): \moodle_url {

        $url = '/pluginfile.php/' . $this->file->contextid . '/' . $this->file->component . '/' . $this->file->filearea;

        if ($insertitemid) {

            $url .= '/' . $this->file->itemid;

        }

        $url .= $this->file->filepath . $this->file->filename;

        return new \moodle_url($url);

    }

    /**

     * Try to get the url for the component (module or course).

     *

     * @return null|\moodle_url

     * @throws \moodle_exception

     */

    protected function get_component_url(): ?\moodle_url {

        if ($this->file->contextlevel == CONTEXT_MODULE) {

            $coursemodinfo = get_fast_modinfo($this->courseid);

            if (!empty($coursemodinfo->cms[$this->file->instanceid])) {

                return $coursemodinfo->cms[$this->file->instanceid]->url;

            }

        }

        return null;

    }

    /**

     * Checks if embedded files have been used

     *

     * @return bool|null

     * @throws \dml_exception

     */

    protected function is_file_used(): ?bool {

        global $DB;

        $component = strpos($this->file->component, 'mod_') === 0 ? 'mod' : $this->file->component;

        switch ($component) {

            case 'mod': // Course module.

                $modname = str_replace('mod_', '', $this->file->component);

                if (!array_key_exists($modname, \core_component::get_plugin_list('mod'))) {

                    return null;

                }

                if ($this->file->filearea === 'intro') {

                    $sql = "SELECT m.*

                              FROM {context} ctx

                              JOIN {course_modules} cm ON cm.id = ctx.instanceid

                              JOIN {{$modname}} m ON m.id = cm.instance

                             WHERE ctx.id = ?";

                    $mod = $DB->get_record_sql($sql, [$this->file->contextid]);

                    return $this->is_embedded_file_used($mod, 'intro', $this->file->filename);

                }

                break;

            case 'question':

                $question = $DB->get_record('question', ['id' => $this->file->itemid]);

                return $this->is_embedded_file_used($question, $this->file->filearea, $this->file->filename);

            case 'qtype_essay':

                $question = $DB->get_record('qtype_essay_options', ['questionid' => $this->file->itemid]);

                return $this->is_embedded_file_used($question, 'graderinfo', $this->file->filename);

        }

        return null;

    }

    /**

     * Test if a file is embedded in text

     *

     * @param \stdClass|false $record

     * @param string $field

     * @param string $filename

     * @return bool|null

     */

    protected function is_embedded_file_used($record, string $field, string $filename): ?bool {

        if ($record && property_exists($record, $field)) {

            return is_int(strpos($record->$field, '@@PLUGINFILE@@/' . rawurlencode($filename)));

        }

        return null;

    }

    /**

     * Creates the URL for the editor where the file is added

     *

     * @return \moodle_url|null

     * @throws \dml_exception

     * @throws \moodle_exception

     */

    protected function get_edit_url(): ?\moodle_url {

        global $DB;

        $component = strpos($this->file->component, 'mod_') === 0 ? 'mod' : $this->file->component;

        switch ($component) {

            case 'mod':

                if ($this->file->filearea === 'intro') { // Just checking description for now.

                    $sql = "SELECT cm.*

                              FROM {context} ctx

                              JOIN {course_modules} cm ON cm.id = ctx.instanceid

                             WHERE ctx.id = ?";

                    $mod = $DB->get_record_sql($sql, [$this->file->contextid]);

                    return new \moodle_url('/course/modedit.php?', ['update' => $mod->id]);

                }

                break;

            case 'question':

            case 'qtype_essay':

                return new \moodle_url('/question/question.php?', ['courseid' => $this->courseid, 'id' => $this->file->itemid]);

        }

        return null;

    }

}