lib/googleapi.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  * Simple implementation of some Google API functions for Moodle.
  19  *
  20  * @package   core
  21  * @copyright Dan Poltawski <talktodan@gmail.com>
  22  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  23  */
  24
  25 defined('MOODLE_INTERNAL') || die();
  26
  27 require_once($CFG->libdir.'/filelib.php');
  28 require_once($CFG->libdir.'/oauthlib.php');
  29
  30 /**
  31  * Class for manipulating google documents through the google data api.
  32  *
  33  * Docs for this can be found here:
  34  * {@link http://code.google.com/apis/documents/docs/2.0/developers_guide_protocol.html}
  35  *
  36  * @package    core
  37  * @subpackage lib
  38  * @copyright Dan Poltawski <talktodan@gmail.com>
  39  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  40  */
  41 class google_docs {
  42     /** @var string Realm for authentication, need both docs and spreadsheet realm */
  43     const REALM            = 'https://docs.google.com/feeds/ https://spreadsheets.google.com/feeds/ https://docs.googleusercontent.com/';
  44     /** @var string Document list url */
  45     const DOCUMENTFEED_URL = 'https://docs.google.com/feeds/default/private/full';
  46     /** @var string Upload url */
  47     const UPLOAD_URL       = 'https://docs.google.com/feeds/upload/create-session/default/private/full?convert=false';
  48
  49     /** @var google_oauth oauth curl class for making authenticated requests */
  50     private $googleoauth = null;
  51
  52     /**
  53      * Constructor.
  54      *
  55      * @param google_oauth $googleoauth oauth curl class for making authenticated requests
  56      */
  57     public function __construct(google_oauth $googleoauth) {
  58         $this->googleoauth = $googleoauth;
  59         $this->reset_curl_state();
  60     }
  61
  62     /**
  63      * Resets state on oauth curl object and set GData protocol
  64      * version
  65      */
  66     private function reset_curl_state() {
  67         $this->googleoauth->reset_state();
  68         $this->googleoauth->setHeader('GData-Version: 3.0');
  69     }
  70
  71     /**
  72      * Returns a list of files the user has formated for files api
  73      *
  74      * @param string $search A search string to do full text search on the documents
  75      * @return mixed Array of files formated for fileapoi
  76      */
  77     public function get_file_list($search = '') {
  78         global $CFG, $OUTPUT;
  79         $url = self::DOCUMENTFEED_URL;
  80
  81         if ($search) {
  82             $url.='?q='.urlencode($search);
  83         }
  84
  85         $files = array();
  86         $content = $this->googleoauth->get($url);
  87         try {
  88             if (strpos($content, '<?xml') !== 0) {
  89                 throw new moodle_exception('invalidxmlresponse');
  90             }
  91             $xml = new SimpleXMLElement($content);
  92         } catch (Exception $e) {
  93             // An error occured while trying to parse the XML, let's just return nothing. SimpleXML does not
  94             // return a more specific Exception, that's why the global Exception class is caught here.
  95             return $files;
  96         }
  97         date_default_timezone_set(core_date::get_user_timezone());
  98         foreach ($xml->entry as $gdoc) {
  99             $docid  = (string) $gdoc->children('http://schemas.google.com/g/2005')->resourceId;
 100             list($type, $docid) = explode(':', $docid);
 101
 102             $title  = '';
 103             $source = '';
 104             // FIXME: We're making hard-coded choices about format here.
 105             // If the repo api can support it, we could let the user
 106             // chose.
 107             switch($type){
 108                 case 'document':
 109                     $title = $gdoc->title.'.rtf';
 110                     $source = 'https://docs.google.com/feeds/download/documents/Export?id='.$docid.'&exportFormat=rtf';
 111                     break;
 112                 case 'presentation':
 113                     $title = $gdoc->title.'.ppt';
 114                     $source = 'https://docs.google.com/feeds/download/presentations/Export?id='.$docid.'&exportFormat=ppt';
 115                     break;
 116                 case 'spreadsheet':
 117                     $title = $gdoc->title.'.xls';
 118                     $source = 'https://spreadsheets.google.com/feeds/download/spreadsheets/Export?key='.$docid.'&exportFormat=xls';
 119                     break;
 120                 case 'pdf':
 121                 case 'file':
 122                     $title  = (string)$gdoc->title;
 123                     // Some files don't have a content probably because the download has been restricted.
 124                     if (isset($gdoc->content)) {
 125                         $source = (string)$gdoc->content[0]->attributes()->src;
 126                     }
 127                     break;
 128             }
 129
 130             $files[] =  array( 'title' => $title,
 131                 'url' => "{$gdoc->link[0]->attributes()->href}",
 132                 'source' => $source,
 133                 'date'   => strtotime($gdoc->updated),
 134                 'thumbnail' => (string) $OUTPUT->image_url(file_extension_icon($title))
 135             );
 136         }
 137         core_date::set_default_server_timezone();
 138
 139         return $files;
 140     }
 141
 142     /**
 143      * Sends a file object to google documents
 144      *
 145      * @param object $file File object
 146      * @return boolean True on success
 147      */
 148     public function send_file($file) {
 149         // First we create the 'resumable upload request'.
 150         $this->googleoauth->setHeader("Content-Length: 0");
 151         $this->googleoauth->setHeader("X-Upload-Content-Length: ". $file->get_filesize());
 152         $this->googleoauth->setHeader("X-Upload-Content-Type: ". $file->get_mimetype());
 153         $this->googleoauth->setHeader("Slug: ". $file->get_filename());
 154         $this->googleoauth->post(self::UPLOAD_URL);
 155
 156         if ($this->googleoauth->info['http_code'] !== 200) {
 157             throw new moodle_exception('Cantpostupload');
 158         }
 159
 160         // Now we http PUT the file in the location returned.
 161         $location = $this->googleoauth->response['Location'];
 162         if (empty($location)) {
 163             throw new moodle_exception('Nouploadlocation');
 164         }
 165
 166         // Reset the curl object for actually sending the file.
 167         $this->reset_curl_state();
 168         $this->googleoauth->setHeader("Content-Length: ". $file->get_filesize());
 169         $this->googleoauth->setHeader("Content-Type: ". $file->get_mimetype());
 170
 171         // We can't get a filepointer, so have to copy the file..
 172         $tmproot = make_temp_directory('googledocsuploads');
 173         $tmpfilepath = $tmproot.'/'.$file->get_contenthash();
 174         $file->copy_content_to($tmpfilepath);
 175
 176         // HTTP PUT the file.
 177         $this->googleoauth->put($location, array('file'=>$tmpfilepath));
 178
 179         // Remove the temporary file we created..
 180         unlink($tmpfilepath);
 181
 182         if ($this->googleoauth->info['http_code'] === 201) {
 183             // Clear headers for further requests.
 184             $this->reset_curl_state();
 185             return true;
 186         } else {
 187             return false;
 188         }
 189     }
 190
 191     /**
 192      * Downloads a file using authentication
 193      *
 194      * @param string $url url of file
 195      * @param string $path path to save file to
 196      * @param int $timeout request timeout, default 0 which means no timeout
 197      * @return array stucture for repository download_file
 198      */
 199     public function download_file($url, $path, $timeout = 0) {
 200         $result = $this->googleoauth->download_one($url, null, array('filepath' => $path, 'timeout' => $timeout));
 201         if ($result === true) {
 202             $info = $this->googleoauth->get_info();
 203             if (isset($info['http_code']) && $info['http_code'] == 200) {
 204                 return array('path'=>$path, 'url'=>$url);
 205             } else {
 206                 throw new moodle_exception('cannotdownload', 'repository');
 207             }
 208         } else {
 209             throw new moodle_exception('errorwhiledownload', 'repository', '', $result);
 210         }
 211     }
 212 }
 213
 214 /**
 215  * OAuth 2.0 client for Google Services
 216  *
 217  * @package   core
 218  * @copyright 2012 Dan Poltawski
 219  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 220  */
 221 class google_oauth extends oauth2_client {
 222     /**
 223      * Returns the auth url for OAuth 2.0 request
 224      * @return string the auth url
 225      */
 226     protected function auth_url() {
 227         return 'https://accounts.google.com/o/oauth2/auth';
 228     }
 229
 230     /**
 231      * Returns the token url for OAuth 2.0 request
 232      * @return string the auth url
 233      */
 234     protected function token_url() {
 235         return 'https://accounts.google.com/o/oauth2/token';
 236     }
 237
 238     /**
 239      * Resets headers and response for multiple requests
 240      */
 241     public function reset_state() {
 242         $this->header = array();
 243         $this->response = array();
 244     }
 245
 246     /**
 247      * Make a HTTP request, we override the parents because we do not
 248      * want to send accept headers (this was a change in the parent class and we want to keep the old behaviour).
 249      *
 250      * @param string $url The URL to request
 251      * @param array $options
 252      * @param mixed $acceptheader Not used.
 253      * @return string
 254      */
 255     protected function request($url, $options = array(), $acceptheader = 'application/json') {
 256         return parent::request($url, $options, false);
 257     }
 258 }