lib.php

<?php
// This file is part of Moodle - https://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 <https://www.gnu.org/licenses/>.

/**
 * The plugin lib
 *
 * @package     tool_lala
 * @copyright   2023 Linda Fernsel <fernsel@htw-berlin.de>
 * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

/**
 * Serve the files from the myplugin file areas.
 *
 * @param stdClass $course the course object
 * @param stdClass $cm the course module object
 * @param stdClass $context the context
 * @param string $filearea the name of the file area
 * @param array $args extra arguments (itemid, path)
 * @param bool $forcedownload whether to force download
 * @param array $options additional options affecting the file serving
 * @return bool false if the file not found, just send the file otherwise and do not return anything
 */
function tool_lala_pluginfile(
        $course,
        $cm,
        $context,
        string $filearea,
        array $args,
        bool $forcedownload,
        array $options = []
): bool {
    // Check the contextlevel is as expected - if your plugin is a block, this becomes CONTEXT_BLOCK, etc.
    if ($context->contextlevel != CONTEXT_SYSTEM) {
        return false;
    }

    // Make sure the filearea is one of those used by the plugin.
    if ($filearea !== 'tool_lala') {
        return false;
    }

    // Make sure the user is logged in and has access to the module.
    require_login();
    require_capability('tool/lala:downloadevidence', $context);

    // The args is an array containing [itemid, path].
    // Fetch the itemid from the path.
    $itemid = array_shift($args);

    // Extract the filename / filepath from the $args array.
    $filename = array_pop($args); // The last item in the $args array.
    if (empty($args)) {
        $filepath = '/';
    } else {
        $filepath = '/' . implode('/', $args) . '/';
    }

    $fs = get_file_storage();
    $file = $fs->get_file($context->id, 'tool_lala', $filearea, $itemid, $filepath, $filename);
    if (!$file) {
        // The file does not exist.
        return false;
    }

    // We can now send the file back to the browser - in this case with a cache lifetime of 1 day and no filtering.
    send_stored_file($file, 86400, 0, $forcedownload, $options);
    return true;
}

/**
 * Insert a link to index.php on the site front page navigation menu.
 *
 * @param navigation_node $frontpage Node representing the front page in the navigation tree.
 */
function tool_lala_extend_navigation_frontpage(navigation_node $frontpage) {
    $context = context_system::instance();
    if (!is_siteadmin() && has_capability('tool/lala:viewpagecontent', $context)) {
        $frontpage->add(
                get_string('pluginname', 'tool_lala'),
                new moodle_url('/admin/tool/lala/index.php')
        );
    }
}