lib.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/>.

/**
 * Extending plugin tool_carcastc functions
 *
 * @package   tool_carcastc
 * @copyright 2021, Carlos Castillo <carlos.castillo@moodle.com>
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

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

/**
 * Extend course navigation to this plugins
 *
 * @param navigation_node $navigation The navigation node to extend
 * @param stdClass $course Course object
 * @param context $context The context of the course
 * @return void|null return null if we don't want to display the node.
 */
function tool_carcastc_extend_navigation_course($navigation, $course, $context) {
    if (has_capability('tool/carcastc:view', $context)) {
        $navigation->add(
                get_string('pluginname', 'tool_carcastc'),
                new moodle_url('/admin/tool/carcastc/index.php', ['courseid' => $course->id]),
                navigation_node::TYPE_SETTING,
                get_string('pluginname', 'tool_carcastc'),
                'carcastc',
                new pix_icon('icon', '', 'tool_carcastc'));
    }
}

/**
 * Serve the files from the tool_carcastc 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 or not force download
 * @param array $options additional options affecting the file serving
 * @return bool false if the file not found, just send the file otherwise and do not return anything
 */
function tool_carcastc_pluginfile($course, $cm, $context, $filearea, $args, $forcedownload, array $options=array()) {
    // Check the contextlevel is as expected - if your plugin is a block, this becomes CONTEXT_BLOCK, etc.
    if ($context->contextlevel != CONTEXT_COURSE) {
        return false;
    }

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

    // Make sure the user is logged in and has access to the module (plugins that are not course modules should
    // leave out the 'cm' part).
    require_login($course);

    // Check the relevant capabilities - these may vary depending on the filearea being accessed.
    require_capability('tool/carcastc:view', $context);

    // Leave this line out if you set the itemid to null in make_pluginfile_url (set $itemid to 0 instead).
    $itemid = array_shift($args); // The first item in the $args array.

    // Use the itemid to retrieve any relevant data records and perform any security checks to see if the
    // user really does have access to the file in question.

    // Extract the filename / filepath from the $args array.
    $filename = array_pop($args); // The last item in the $args array.
    if (!$args) {
        $filepath = '/'; // ...$args is empty => the path is '/'
    } else {
        $filepath = '/'.implode('/', $args).'/'; // ...$args contains elements of the filepath
    }

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

    // 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, null, 0, $forcedownload, $options);
}