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Differences Between: [Versions 310 and 311] [Versions 310 and 400] [Versions 310 and 401] [Versions 310 and 402] [Versions 310 and 403] [Versions 39 and 310]

   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   * Provides {@link flickr_client} class.
  19   *
  20   * @package     core
  21   * @copyright   2017 David Mudrák <david@moodle.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.'/oauthlib.php');
  28  
  29  /**
  30   * Simple Flickr API client implementing the features needed by Moodle
  31   *
  32   * @copyright 2017 David Mudrak <david@moodle.com>
  33   * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  34   */
  35  class flickr_client extends oauth_helper {
  36  
  37      /**
  38       * Base URL for Flickr OAuth 1.0 API calls.
  39       */
  40      const OAUTH_ROOT = 'https://www.flickr.com/services/oauth';
  41  
  42      /**
  43       * Base URL for Flickr REST API calls.
  44       */
  45      const REST_ROOT = 'https://api.flickr.com/services/rest';
  46  
  47      /**
  48       * Base URL for Flickr Upload API call.
  49       */
  50      const UPLOAD_ROOT = 'https://up.flickr.com/services/upload/';
  51  
  52      /**
  53       * Set up OAuth and initialize the client.
  54       *
  55       * The callback URL specified here will override the one specified in the
  56       * auth flow defined at Flickr Services.
  57       *
  58       * @param string $consumerkey
  59       * @param string $consumersecret
  60       * @param moodle_url|string $callbackurl
  61       */
  62      public function __construct($consumerkey, $consumersecret, $callbackurl = '') {
  63          global $CFG;
  64          $version = moodle_major_version();
  65          $useragent = "MoodleSite/$version (+{$CFG->wwwroot})";
  66  
  67          parent::__construct([
  68              'api_root' => self::OAUTH_ROOT,
  69              'oauth_consumer_key' => $consumerkey,
  70              'oauth_consumer_secret' => $consumersecret,
  71              'oauth_callback' => $callbackurl,
  72              'http_options' => ['CURLOPT_USERAGENT' => $useragent]
  73          ]);
  74      }
  75  
  76      /**
  77       * Temporarily store the request token secret in the session.
  78       *
  79       * The request token secret is returned by the oauth request_token method.
  80       * It needs to be stored in the session before the user is redirected to
  81       * the Flickr to authorize the client. After redirecting back, this secret
  82       * is used for exchanging the request token with the access token.
  83       *
  84       * The identifiers help to avoid collisions between multiple calls to this
  85       * method from different plugins in the same session. They are used as the
  86       * session cache identifiers. Provide an associative array identifying the
  87       * particular method call. At least, the array must contain the 'caller'
  88       * with the caller's component name. Use additional items if needed.
  89       *
  90       * @param array $identifiers Identification of the call
  91       * @param string $secret
  92       */
  93      public function set_request_token_secret(array $identifiers, $secret) {
  94  
  95          if (empty($identifiers) || empty($identifiers['caller'])) {
  96              throw new coding_exception('Invalid call identification');
  97          }
  98  
  99          $cache = cache::make_from_params(cache_store::MODE_SESSION, 'core', 'flickrclient', $identifiers);
 100          $cache->set('request_token_secret', $secret);
 101      }
 102  
 103      /**
 104       * Returns previously stored request token secret.
 105       *
 106       * See {@link self::set_request_token_secret()} for more details on the
 107       * $identifiers argument.
 108       *
 109       * @param array $identifiers Identification of the call
 110       * @return string|bool False on error, string secret otherwise.
 111       */
 112      public function get_request_token_secret(array $identifiers) {
 113  
 114          if (empty($identifiers) || empty($identifiers['caller'])) {
 115              throw new coding_exception('Invalid call identification');
 116          }
 117  
 118          $cache = cache::make_from_params(cache_store::MODE_SESSION, 'core', 'flickrclient', $identifiers);
 119  
 120          return $cache->get('request_token_secret');
 121      }
 122  
 123      /**
 124       * Call a Flickr API method.
 125       *
 126       * @param string $function API function name like 'flickr.photos.getSizes' or just 'photos.getSizes'
 127       * @param array $params Additional API call arguments.
 128       * @param string $method HTTP method to use (GET or POST).
 129       * @return object|bool Response as returned by the Flickr or false on invalid authentication
 130       */
 131      public function call($function, array $params = [], $method = 'GET') {
 132  
 133          if (strpos($function, 'flickr.') !== 0) {
 134              $function = 'flickr.'.$function;
 135          }
 136  
 137          $params['method'] = $function;
 138          $params['format'] = 'json';
 139          $params['nojsoncallback'] = 1;
 140  
 141          $rawresponse = $this->request($method, self::REST_ROOT, $params);
 142          $response = json_decode($rawresponse);
 143  
 144          if (!is_object($response) || !isset($response->stat)) {
 145              throw new moodle_exception('flickr_api_call_failed', 'core_error', '', $rawresponse);
 146          }
 147  
 148          if ($response->stat === 'ok') {
 149              return $response;
 150  
 151          } else if ($response->stat === 'fail' && $response->code == 98) {
 152              // Authentication failure, give the caller a chance to re-authenticate.
 153              return false;
 154  
 155          } else {
 156              throw new moodle_exception('flickr_api_call_failed', 'core_error', '', $response);
 157          }
 158  
 159          return $response;
 160      }
 161  
 162      /**
 163       * Return the URL to fetch the given photo from.
 164       *
 165       * Flickr photos are distributed via farm servers staticflickr.com in
 166       * various sizes (resolutions). The method tries to find the source URL of
 167       * the photo in the highest possible resolution. Results are cached so that
 168       * we do not need to query the Flickr API over and over again.
 169       *
 170       * @param string $photoid Flickr photo identifier
 171       * @return string URL
 172       */
 173      public function get_photo_url($photoid) {
 174  
 175          $cache = cache::make_from_params(cache_store::MODE_APPLICATION, 'core', 'flickrclient');
 176  
 177          $url = $cache->get('photourl_'.$photoid);
 178  
 179          if ($url === false) {
 180              $response = $this->call('photos.getSizes', ['photo_id' => $photoid]);
 181              // Sizes are returned from smallest to greatest.
 182              if (!empty($response->sizes->size) && is_array($response->sizes->size)) {
 183                  while ($bestsize = array_pop($response->sizes->size)) {
 184                      if (isset($bestsize->source)) {
 185                          $url = $bestsize->source;
 186                          break;
 187                      }
 188                  }
 189              }
 190          }
 191  
 192          if ($url === false) {
 193              throw new repository_exception('cannotdownload', 'repository');
 194  
 195          } else {
 196              $cache->set('photourl_'.$photoid, $url);
 197          }
 198  
 199          return $url;
 200      }
 201  
 202      /**
 203       * Upload a photo from Moodle file pool to Flickr.
 204       *
 205       * Optional meta information are title, description, tags, is_public,
 206       * is_friend, is_family, safety_level, content_type and hidden.
 207       * See {@link https://www.flickr.com/services/api/upload.api.html}.
 208       *
 209       * Upload can't be asynchronous because then the query would not return the
 210       * photo ID which we need to add the photo to a photoset (album)
 211       * eventually.
 212       *
 213       * @param stored_file $photo stored in Moodle file pool
 214       * @param array $meta optional meta information
 215       * @return int|bool photo id, false on authentication failure
 216       */
 217      public function upload(stored_file $photo, array $meta = []) {
 218  
 219          $args = [
 220              'title' => isset($meta['title']) ? $meta['title'] : null,
 221              'description' => isset($meta['description']) ? $meta['description'] : null,
 222              'tags' => isset($meta['tags']) ? $meta['tags'] : null,
 223              'is_public' => isset($meta['is_public']) ? $meta['is_public'] : 0,
 224              'is_friend' => isset($meta['is_friend']) ? $meta['is_friend'] : 0,
 225              'is_family' => isset($meta['is_family']) ? $meta['is_family'] : 0,
 226              'safety_level' => isset($meta['safety_level']) ? $meta['safety_level'] : 1,
 227              'content_type' => isset($meta['content_type']) ? $meta['content_type'] : 1,
 228              'hidden' => isset($meta['hidden']) ? $meta['hidden'] : 2,
 229          ];
 230  
 231          $this->sign_secret = $this->consumer_secret.'&'.$this->access_token_secret;
 232          $params = $this->prepare_oauth_parameters(self::UPLOAD_ROOT, ['oauth_token' => $this->access_token] + $args, 'POST');
 233  
 234          $params['photo'] = $photo;
 235  
 236          $response = $this->http->post(self::UPLOAD_ROOT, $params);
 237  
 238          // Reset http header and options to prepare for the next request.
 239          $this->reset_state();
 240  
 241          if ($response) {
 242              $xml = simplexml_load_string($response);
 243  
 244              if ((string)$xml['stat'] === 'ok') {
 245                  return (int)$xml->photoid;
 246  
 247              } else if ((string)$xml['stat'] === 'fail' && (int)$xml->err['code'] == 98) {
 248                  // Authentication failure.
 249                  return false;
 250  
 251              } else {
 252                  throw new moodle_exception('flickr_upload_failed', 'core_error', '',
 253                      ['code' => (int)$xml->err['code'], 'message' => (string)$xml->err['msg']]);
 254              }
 255  
 256          } else {
 257              throw new moodle_exception('flickr_upload_error', 'core_error', '', null, $response);
 258          }
 259      }
 260  
 261      /**
 262       * Resets curl state.
 263       *
 264       * @return void
 265       */
 266      public function reset_state(): void {
 267          $this->http->cleanopt();
 268          $this->http->resetHeader();
 269      }
 270  }