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      * Youtube plugin constructor
  42      * @param int $repositoryid
  43      * @param object $context
  44      * @param array $options
  45      */
  46     public function __construct($repositoryid, $context = SYSCONTEXTID, $options = array()) {
  47         parent::__construct($repositoryid, $context, $options);
  48     }
  49
  50     public function check_login() {
  51         return !empty($this->keyword);
  52     }
  53
  54     /**
  55      * Return search results
  56      * @param string $search_text
  57      * @return array
  58      */
  59     public function search($search_text, $page = 0) {
  60         global $SESSION;
  61         $sort = optional_param('youtube_sort', '', PARAM_TEXT);
  62         $sess_keyword = 'youtube_'.$this->id.'_keyword';
  63         $sess_sort = 'youtube_'.$this->id.'_sort';
  64
  65         // This is the request of another page for the last search, retrieve the cached keyword and sort
  66         if ($page && !$search_text && isset($SESSION->{$sess_keyword})) {
  67             $search_text = $SESSION->{$sess_keyword};
  68         }
  69         if ($page && !$sort && isset($SESSION->{$sess_sort})) {
  70             $sort = $SESSION->{$sess_sort};
  71         }
  72         if (!$sort) {
  73             $sort = 'relevance'; // default
  74         }
  75
  76         // Save this search in session
  77         $SESSION->{$sess_keyword} = $search_text;
  78         $SESSION->{$sess_sort} = $sort;
  79
  80         $this->keyword = $search_text;
  81         $ret  = array();
  82         $ret['nologin'] = true;
  83         $ret['page'] = (int)$page;
  84         if ($ret['page'] < 1) {
  85             $ret['page'] = 1;
  86         }
  87         $start = ($ret['page'] - 1) * self::YOUTUBE_THUMBS_PER_PAGE + 1;
  88         $max = self::YOUTUBE_THUMBS_PER_PAGE;
  89         $ret['list'] = $this->_get_collection($search_text, $start, $max, $sort);
  90         $ret['norefresh'] = true;
  91         $ret['nosearch'] = true;
  92         // If the number of results is smaller than $max, it means we reached the last page.
  93         $ret['pages'] = (count($ret['list']) < $max) ? $ret['page'] : -1;
  94         return $ret;
  95     }
  96
  97     /**
  98      * Private method to get youtube search results
  99      * @param string $keyword
 100      * @param int $start
 101      * @param int $max max results
 102      * @param string $sort
 103      * @return array
 104      */
 105     private function _get_collection($keyword, $start, $max, $sort) {
 106         $list = array();
 107         $this->feed_url = 'http://gdata.youtube.com/feeds/api/videos?q=' . urlencode($keyword) . '&format=5&start-index=' . $start . '&max-results=' .$max . '&orderby=' . $sort;
 108         $c = new curl(array('cache'=>true, 'module_cache'=>'repository'));
 109         $content = $c->get($this->feed_url);
 110         $xml = simplexml_load_string($content);
 111         $media = $xml->entry->children('http://search.yahoo.com/mrss/');
 112         $links = $xml->children('http://www.w3.org/2005/Atom');
 113         foreach ($xml->entry as $entry) {
 114             $media = $entry->children('http://search.yahoo.com/mrss/');
 115             $title = (string)$media->group->title;
 116             $description = (string)$media->group->description;
 117             if (empty($description)) {
 118                 $description = $title;
 119             }
 120             $attrs = $media->group->thumbnail[2]->attributes();
 121             $thumbnail = $attrs['url'];
 122             $arr = explode('/', $entry->id);
 123             $id = $arr[count($arr)-1];
 124             $source = 'http://www.youtube.com/v/' . $id . '#' . $title;
 125             $list[] = array(
 126                 'shorttitle'=>$title,
 127                 'thumbnail_title'=>$description,
 128                 'title'=>$title.'.avi', // this is a hack so we accept this file by extension
 129                 'thumbnail'=>(string)$attrs['url'],
 130                 'thumbnail_width'=>(int)$attrs['width'],
 131                 'thumbnail_height'=>(int)$attrs['height'],
 132                 'size'=>'',
 133                 'date'=>'',
 134                 'source'=>$source
 135             );
 136         }
 137         return $list;
 138     }
 139
 140     /**
 141      * Youtube plugin doesn't support global search
 142      */
 143     public function global_search() {
 144         return false;
 145     }
 146
 147     public function get_listing($path='', $page = '') {
 148         return array();
 149     }
 150
 151     /**
 152      * Generate search form
 153      */
 154     public function print_login($ajax = true) {
 155         $ret = array();
 156         $search = new stdClass();
 157         $search->type = 'text';
 158         $search->id   = 'youtube_search';
 159         $search->name = 's';
 160         $search->label = get_string('search', 'repository_youtube').': ';
 161         $sort = new stdClass();
 162         $sort->type = 'select';
 163         $sort->options = array(
 164             (object)array(
 165                 'value' => 'relevance',
 166                 'label' => get_string('sortrelevance', 'repository_youtube')
 167             ),
 168             (object)array(
 169                 'value' => 'published',
 170                 'label' => get_string('sortpublished', 'repository_youtube')
 171             ),
 172             (object)array(
 173                 'value' => 'rating',
 174                 'label' => get_string('sortrating', 'repository_youtube')
 175             ),
 176             (object)array(
 177                 'value' => 'viewCount',
 178                 'label' => get_string('sortviewcount', 'repository_youtube')
 179             )
 180         );
 181         $sort->id = 'youtube_sort';
 182         $sort->name = 'youtube_sort';
 183         $sort->label = get_string('sortby', 'repository_youtube').': ';
 184         $ret['login'] = array($search, $sort);
 185         $ret['login_btn_label'] = get_string('search');
 186         $ret['login_btn_action'] = 'search';
 187         $ret['allowcaching'] = true; // indicates that login form can be cached in filepicker.js
 188         return $ret;
 189     }
 190
 191     /**
 192      * file types supported by youtube plugin
 193      * @return array
 194      */
 195     public function supported_filetypes() {
 196         return array('video');
 197     }
 198
 199     /**
 200      * Youtube plugin only return external links
 201      * @return int
 202      */
 203     public function supported_returntypes() {
 204         return FILE_EXTERNAL;
 205     }
 206
 207     /**
 208      * Is this repository accessing private data?
 209      *
 210      * @return bool
 211      */
 212     public function contains_private_data() {
 213         return false;
 214     }
 215 }