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 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 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         $ret['pages'] = -1;
  93         return $ret;
  94     }
  95
  96     /**
  97      * Private method to get youtube search results
  98      * @param string $keyword
  99      * @param int $start
 100      * @param int $max max results
 101      * @param string $sort
 102      * @return array
 103      */
 104     private function _get_collection($keyword, $start, $max, $sort) {
 105         $list = array();
 106         $this->feed_url = 'http://gdata.youtube.com/feeds/api/videos?q=' . urlencode($keyword) . '&format=5&start-index=' . $start . '&max-results=' .$max . '&orderby=' . $sort;
 107         $c = new curl(array('cache'=>true, 'module_cache'=>'repository'));
 108         $content = $c->get($this->feed_url);
 109         $xml = simplexml_load_string($content);
 110         $media = $xml->entry->children('http://search.yahoo.com/mrss/');
 111         $links = $xml->children('http://www.w3.org/2005/Atom');
 112         foreach ($xml->entry as $entry) {
 113             $media = $entry->children('http://search.yahoo.com/mrss/');
 114             $title = $media->group->title;
 115             $attrs = $media->group->thumbnail[2]->attributes();
 116             $thumbnail = $attrs['url'];
 117             $arr = explode('/', $entry->id);
 118             $id = $arr[count($arr)-1];
 119             $source = 'http://www.youtube.com/v/' . $id . '#' . $title;
 120             $list[] = array(
 121                 'title'=>(string)$title,
 122                 'thumbnail'=>(string)$attrs['url'],
 123                 'thumbnail_width'=>150,
 124                 'thumbnail_height'=>120,
 125                 'size'=>'',
 126                 'date'=>'',
 127                 'source'=>$source
 128             );
 129         }
 130         return $list;
 131     }
 132
 133     /**
 134      * Youtube plugin doesn't support global search
 135      */
 136     public function global_search() {
 137         return false;
 138     }
 139
 140     public function get_listing($path='', $page = '') {
 141         return array();
 142     }
 143
 144     /**
 145      * Generate search form
 146      */
 147     public function print_login($ajax = true) {
 148         $ret = array();
 149         $search = new stdClass();
 150         $search->type = 'text';
 151         $search->id   = 'youtube_search';
 152         $search->name = 's';
 153         $search->label = get_string('search', 'repository_youtube').': ';
 154         $sort = new stdClass();
 155         $sort->type = 'select';
 156         $sort->options = array(
 157             (object)array(
 158                 'value' => 'relevance',
 159                 'label' => get_string('sortrelevance', 'repository_youtube')
 160             ),
 161             (object)array(
 162                 'value' => 'published',
 163                 'label' => get_string('sortpublished', 'repository_youtube')
 164             ),
 165             (object)array(
 166                 'value' => 'rating',
 167                 'label' => get_string('sortrating', 'repository_youtube')
 168             ),
 169             (object)array(
 170                 'value' => 'viewCount',
 171                 'label' => get_string('sortviewcount', 'repository_youtube')
 172             )
 173         );
 174         $sort->id = 'youtube_sort';
 175         $sort->name = 'youtube_sort';
 176         $sort->label = get_string('sortby', 'repository_youtube').': ';
 177         $ret['login'] = array($search, $sort);
 178         $ret['login_btn_label'] = get_string('search');
 179         $ret['login_btn_action'] = 'search';
 180         $ret['allowcaching'] = true; // indicates that login form can be cached in filepicker.js
 181         return $ret;
 182     }
 183
 184     /**
 185      * file types supported by youtube plugin
 186      * @return array
 187      */
 188     public function supported_filetypes() {
 189         return array('web_video');
 190     }
 191
 192     /**
 193      * Youtube plugin only return external links
 194      * @return int
 195      */
 196     public function supported_returntypes() {
 197         return FILE_EXTERNAL;
 198     }
 199 }