repository/youtube/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  * This plugin is used to access youtube videos
  19  *
  20  * @since Moodle 2.0
  21  * @package    repository_youtube
  22  * @copyright  2010 Dongsheng Cai {@link http://dongsheng.org}
  23  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25 require_once($CFG->dirroot . '/repository/lib.php');
  26
  27 /**
  28  * repository_youtube class
  29  *
  30  * @since Moodle 2.0
  31  * @package    repository_youtube
  32  * @copyright  2009 Dongsheng Cai {@link http://dongsheng.org}
  33  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  34  */
  35
  36 class repository_youtube extends repository {
  37     /** @var int maximum number of thumbs per page */
  38     const YOUTUBE_THUMBS_PER_PAGE = 27;
  39
  40     /**
  41      * API key for using the YouTube Data API.
  42      * @var mixed
  43      */
  44     private $apikey;
  45
  46     /**
  47      * Google Client.
  48      * @var Google_Client
  49      */
  50     private $client = null;
  51
  52     /**
  53      * YouTube Service.
  54      * @var Google_Service_YouTube
  55      */
  56     private $service = null;
  57
  58     /**
  59      * Youtube plugin constructor
  60      * @param int $repositoryid
  61      * @param object $context
  62      * @param array $options
  63      */
  64     public function __construct($repositoryid, $context = SYSCONTEXTID, $options = array()) {
  65         parent::__construct($repositoryid, $context, $options);
  66
  67         $this->apikey = $this->get_option('apikey');
  68
  69         // Without an API key, don't show this repo to users as its useless without it.
  70         if (empty($this->apikey)) {
  71             $this->disabled = true;
  72         }
  73     }
  74
  75     /**
  76      * Init all the youtube client service stuff.
  77      *
  78      * Instead of instantiating the service in the constructor, we delay
  79      * it until really neeed because it's really memory hungry (2MB). That
  80      * way the editor or any other artifact requiring repository instantiation
  81      * can do it in a cheap way. Sort of lazy loading the plugin.
  82      */
  83     private function init_youtube_service() {
  84         global $CFG;
  85
  86         if (!isset($this->service)) {
  87             require_once($CFG->libdir . '/google/lib.php');
  88             $this->client = get_google_client();
  89             $this->client->setDeveloperKey($this->apikey);
  90             $this->client->setScopes(array(Google_Service_YouTube::YOUTUBE_READONLY));
  91             $this->service = new Google_Service_YouTube($this->client);
  92         }
  93     }
  94
  95     /**
  96      * Save apikey in config table.
  97      * @param array $options
  98      * @return boolean
  99      */
 100     public function set_option($options = array()) {
 101         if (!empty($options['apikey'])) {
 102             set_config('apikey', trim($options['apikey']), 'youtube');
 103         }
 104         unset($options['apikey']);
 105         return parent::set_option($options);
 106     }
 107
 108     /**
 109      * Get apikey from config table.
 110      *
 111      * @param string $config
 112      * @return mixed
 113      */
 114     public function get_option($config = '') {
 115         if ($config === 'apikey') {
 116             return trim(get_config('youtube', 'apikey'));
 117         } else {
 118             $options['apikey'] = trim(get_config('youtube', 'apikey'));
 119         }
 120         return parent::get_option($config);
 121     }
 122
 123     public function check_login() {
 124         return !empty($this->keyword);
 125     }
 126
 127     /**
 128      * Return search results
 129      * @param string $search_text
 130      * @return array
 131      */
 132     public function search($search_text, $page = 0) {
 133         global $SESSION;
 134         $sort = optional_param('youtube_sort', '', PARAM_TEXT);
 135         $sess_keyword = 'youtube_'.$this->id.'_keyword';
 136         $sess_sort = 'youtube_'.$this->id.'_sort';
 137
 138         // This is the request of another page for the last search, retrieve the cached keyword and sort
 139         if ($page && !$search_text && isset($SESSION->{$sess_keyword})) {
 140             $search_text = $SESSION->{$sess_keyword};
 141         }
 142         if ($page && !$sort && isset($SESSION->{$sess_sort})) {
 143             $sort = $SESSION->{$sess_sort};
 144         }
 145         if (!$sort) {
 146             $sort = 'relevance'; // default
 147         }
 148
 149         // Save this search in session
 150         $SESSION->{$sess_keyword} = $search_text;
 151         $SESSION->{$sess_sort} = $sort;
 152
 153         $this->keyword = $search_text;
 154         $ret  = array();
 155         $ret['nologin'] = true;
 156         $ret['page'] = (int)$page;
 157         if ($ret['page'] < 1) {
 158             $ret['page'] = 1;
 159         }
 160         $start = ($ret['page'] - 1) * self::YOUTUBE_THUMBS_PER_PAGE + 1;
 161         $max = self::YOUTUBE_THUMBS_PER_PAGE;
 162         $ret['list'] = $this->_get_collection($search_text, $start, $max, $sort);
 163         $ret['norefresh'] = true;
 164         $ret['nosearch'] = true;
 165         // If the number of results is smaller than $max, it means we reached the last page.
 166         $ret['pages'] = (count($ret['list']) < $max) ? $ret['page'] : -1;
 167         return $ret;
 168     }
 169
 170     /**
 171      * Private method to get youtube search results
 172      * @param string $keyword
 173      * @param int $start
 174      * @param int $max max results
 175      * @param string $sort
 176      * @throws moodle_exception If the google API returns an error.
 177      * @return array
 178      */
 179     private function _get_collection($keyword, $start, $max, $sort) {
 180         global $SESSION;
 181
 182         // The new API doesn't use "page" numbers for browsing through results.
 183         // It uses a prev and next token in each set that you need to use to
 184         // request the next page of results.
 185         $sesspagetoken = 'youtube_'.$this->id.'_nextpagetoken';
 186         $pagetoken = '';
 187         if ($start > 1 && isset($SESSION->{$sesspagetoken})) {
 188             $pagetoken = $SESSION->{$sesspagetoken};
 189         }
 190
 191         $list = array();
 192         $error = null;
 193         try {
 194             $this->init_youtube_service(); // About to use the service, ensure it's loaded.
 195             $response = $this->service->search->listSearch('id,snippet', array(
 196                 'q' => $keyword,
 197                 'maxResults' => $max,
 198                 'order' => $sort,
 199                 'pageToken' => $pagetoken,
 200                 'type' => 'video',
 201                 'videoEmbeddable' => 'true',
 202             ));
 203
 204             // Track the next page token for the next request (when a user
 205             // scrolls down in the file picker for more videos).
 206             $SESSION->{$sesspagetoken} = $response['nextPageToken'];
 207
 208             foreach ($response['items'] as $result) {
 209                 $title = $result->snippet->title;
 210                 $source = 'http://www.youtube.com/v/' . $result->id->videoId . '#' . $title;
 211                 $thumb = $result->snippet->getThumbnails()->getDefault();
 212
 213                 $list[] = array(
 214                     'shorttitle' => $title,
 215                     'thumbnail_title' => $result->snippet->description,
 216                     'title' => $title.'.avi', // This is a hack so we accept this file by extension.
 217                     'thumbnail' => $thumb->url,
 218                     'thumbnail_width' => (int)$thumb->width,
 219                     'thumbnail_height' => (int)$thumb->height,
 220                     'size' => '',
 221                     'date' => '',
 222                     'source' => $source,
 223                 );
 224             }
 225         } catch (Google_Service_Exception $e) {
 226             // If we throw the google exception as-is, we may expose the apikey
 227             // to end users. The full message in the google exception includes
 228             // the apikey param, so we take just the part pertaining to the
 229             // actual error.
 230             $error = $e->getErrors()[0]['message'];
 231             throw new moodle_exception('apierror', 'repository_youtube', '', $error);
 232         }
 233
 234         return $list;
 235     }
 236
 237     /**
 238      * Youtube plugin doesn't support global search
 239      */
 240     public function global_search() {
 241         return false;
 242     }
 243
 244     public function get_listing($path='', $page = '') {
 245         return array();
 246     }
 247
 248     /**
 249      * Generate search form
 250      */
 251     public function print_login($ajax = true) {
 252         $ret = array();
 253         $search = new stdClass();
 254         $search->type = 'text';
 255         $search->id   = 'youtube_search';
 256         $search->name = 's';
 257         $search->label = get_string('search', 'repository_youtube').': ';
 258         $sort = new stdClass();
 259         $sort->type = 'select';
 260         $sort->options = array(
 261             (object)array(
 262                 'value' => 'relevance',
 263                 'label' => get_string('sortrelevance', 'repository_youtube')
 264             ),
 265             (object)array(
 266                 'value' => 'date',
 267                 'label' => get_string('sortpublished', 'repository_youtube')
 268             ),
 269             (object)array(
 270                 'value' => 'rating',
 271                 'label' => get_string('sortrating', 'repository_youtube')
 272             ),
 273             (object)array(
 274                 'value' => 'viewCount',
 275                 'label' => get_string('sortviewcount', 'repository_youtube')
 276             )
 277         );
 278         $sort->id = 'youtube_sort';
 279         $sort->name = 'youtube_sort';
 280         $sort->label = get_string('sortby', 'repository_youtube').': ';
 281         $ret['login'] = array($search, $sort);
 282         $ret['login_btn_label'] = get_string('search');
 283         $ret['login_btn_action'] = 'search';
 284         $ret['allowcaching'] = true; // indicates that login form can be cached in filepicker.js
 285         return $ret;
 286     }
 287
 288     /**
 289      * file types supported by youtube plugin
 290      * @return array
 291      */
 292     public function supported_filetypes() {
 293         return array('video');
 294     }
 295
 296     /**
 297      * Youtube plugin only return external links
 298      * @return int
 299      */
 300     public function supported_returntypes() {
 301         return FILE_EXTERNAL;
 302     }
 303
 304     /**
 305      * Is this repository accessing private data?
 306      *
 307      * @return bool
 308      */
 309     public function contains_private_data() {
 310         return false;
 311     }
 312
 313     /**
 314      * Add plugin settings input to Moodle form.
 315      * @param object $mform
 316      * @param string $classname
 317      */
 318     public static function type_config_form($mform, $classname = 'repository') {
 319         parent::type_config_form($mform, $classname);
 320         $apikey = get_config('youtube', 'apikey');
 321         if (empty($apikey)) {
 322             $apikey = '';
 323         }
 324
 325         $mform->addElement('text', 'apikey', get_string('apikey', 'repository_youtube'), array('value' => $apikey, 'size' => '40'));
 326         $mform->setType('apikey', PARAM_RAW_TRIMMED);
 327         $mform->addRule('apikey', get_string('required'), 'required', null, 'client');
 328
 329         $mform->addElement('static', null, '',  get_string('information', 'repository_youtube'));
 330     }
 331
 332     /**
 333      * Names of the plugin settings
 334      * @return array
 335      */
 336     public static function get_type_option_names() {
 337         return array('apikey', 'pluginname');
 338     }
 339 }