h5p/lib.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * Callbacks.
  19  *
  20  * @package    core_h5p
  21  * @copyright  2019 Bas Brands <bas@moodle.com>
  22  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24 defined('MOODLE_INTERNAL') || die();
  25
  26 use core_h5p\local\library\autoloader;
  27
  28 /**
  29  * Serve the files from the core_h5p file areas.
  30  *
  31  * @package core_h5p
  32  * @category files
  33  *
  34  * @param  stdClass $course the course object
  35  * @param  stdClass $cm the course module object
  36  * @param  stdClass $context the newmodule's context
  37  * @param  string $filearea the name of the file area
  38  * @param  array $args extra arguments (itemid, path)
  39  * @param  bool $forcedownload whether or not force download
  40  * @param  array $options additional options affecting the file serving
  41  *
  42  * @return bool Returns false if we don't find a file.
  43  */
  44 function core_h5p_pluginfile($course, $cm, $context, string $filearea, array $args, bool $forcedownload,
  45     array $options = []) : bool {
  46     global $DB;
  47
  48     // Require classes from H5P third party library
  49     autoloader::register();
  50
  51     $filesettingsset = false;
  52
  53     switch ($filearea) {
  54         default:
  55             return false; // Invalid file area.
  56
  57         case \core_h5p\file_storage::LIBRARY_FILEAREA:
  58             if ($context->contextlevel != CONTEXT_SYSTEM) {
  59                  return false; // Invalid context because the libraries are loaded always in the context system.
  60             }
  61
  62             $itemid = null;
  63
  64             // The files that can be delivered to this function are unfortunately out of our control. Some of the
  65             // references are embedded into the JavaScript of the files and we have no ability to inject an item id.
  66             // We also don't know the location of the item id when we do include it, so we look for the first numeric
  67             // value and try to serve that file.
  68             foreach ($args as $key => $value) {
  69                 if (is_numeric($value)) {
  70                     $itemid = $value;
  71                     unset($args[$key]);
  72                     break;
  73                 }
  74             }
  75
  76             if (!isset($itemid)) {
  77                 // We didn't find an item id to use, so we fall back to retrieving the record using all the other
  78                 // fields. The combination of component, filearea, filepath, and filename is enough for a unique
  79                 // record.
  80                 $filename = array_pop($args);
  81                 $filepath = '/' . implode('/', $args) . '/';
  82                 $itemid = $DB->get_field('files', 'itemid', [
  83                     'component' => \core_h5p\file_storage::COMPONENT,
  84                     'filearea' => \core_h5p\file_storage::LIBRARY_FILEAREA,
  85                     'filepath' => $filepath,
  86                     'filename' => $filename
  87                 ]);
  88                 $filesettingsset = true;
  89             }
  90             break;
  91         case \core_h5p\file_storage::CONTENT_FILEAREA:
  92             if ($context->contextlevel != CONTEXT_SYSTEM) {
  93                 return false; // Invalid context because the content files are loaded always in the context system.
  94             }
  95             $itemid = array_shift($args);
  96             break;
  97         case \core_h5p\file_storage::CACHED_ASSETS_FILEAREA:
  98         case \core_h5p\file_storage::EXPORT_FILEAREA:
  99             $itemid = 0;
 100             break;
 101     }
 102
 103     if (!$filesettingsset) {
 104         $filename = array_pop($args);
 105         $filepath = (!$args ? '/' : '/' . implode('/', $args) . '/');
 106     }
 107
 108     $fs = get_file_storage();
 109     $file = $fs->get_file($context->id, \core_h5p\file_storage::COMPONENT, $filearea, $itemid, $filepath, $filename);
 110     if (!$file) {
 111         return false; // No such file.
 112     }
 113
 114     send_stored_file($file, null, 0, $forcedownload, $options);
 115
 116     return true;
 117 }