plugins/pubsubhubbub/pubsubhubbub.php

   1 <?php
   2
   3 /**
   4  * PubSubHubbub plugin.
   5  *
   6  * PubSub is a protocol which fasten up RSS fetching:
   7  *   - Every time a new link is posted, Shaarli notify the hub.
   8  *   - The hub notify all feed subscribers that a new link has been posted.
   9  *   - Subscribers retrieve the new link.
  10  */
  11
  12 use pubsubhubbub\publisher\Publisher;
  13
  14 /**
  15  * Plugin init function - set the hub to the default appspot one.
  16  *
  17  * @param ConfigManager $conf instance.
  18  */
  19 function pubsubhubbub_init($conf)
  20 {
  21     $hub = $conf->get('plugins.PUBSUBHUB_URL');
  22     if (empty($hub)) {
  23         // Default hub.
  24         $conf->set('plugins.PUBSUBHUB_URL', 'https://pubsubhubbub.appspot.com/');
  25     }
  26 }
  27
  28
  29 /**
  30  * Render feed hook.
  31  * Adds the hub URL in ATOM and RSS feed.
  32  *
  33  * @param array         $data Template data.
  34  * @param ConfigManager $conf instance.
  35  *
  36  * @return array updated template data.
  37  */
  38 function hook_pubsubhubbub_render_feed($data, $conf)
  39 {
  40     $feedType = $data['_PAGE_'] == Router::$PAGE_FEED_RSS ? FeedBuilder::$FEED_RSS : FeedBuilder::$FEED_ATOM;
  41     $template = file_get_contents(PluginManager::$PLUGINS_PATH . '/pubsubhubbub/hub.'. $feedType .'.xml');
  42     $data['feed_plugins_header'][] = sprintf($template, $conf->get('plugins.PUBSUBHUB_URL'));
  43
  44     return $data;
  45 }
  46
  47 /**
  48  * Save link hook.
  49  * Publish to the hub when a link is saved.
  50  *
  51  * @param array         $data Template data.
  52  * @param ConfigManager $conf instance.
  53  *
  54  * @return array unaltered data.
  55  */
  56 function hook_pubsubhubbub_save_link($data, $conf)
  57 {
  58     $feeds = array(
  59         index_url($_SERVER) .'?do=atom',
  60         index_url($_SERVER) .'?do=rss',
  61     );
  62
  63     $httpPost = function_exists('curl_version') ? false : 'nocurl_http_post';
  64     try {
  65         $p = new Publisher($conf->get('plugins.PUBSUBHUB_URL'));
  66         $p->publish_update($feeds, $httpPost);
  67     } catch (Exception $e) {
  68         error_log('Could not publish to PubSubHubbub: ' . $e->getMessage());
  69     }
  70
  71     return $data;
  72 }
  73
  74 /**
  75  * Http function used to post to the hub endpoint without cURL extension.
  76  *
  77  * @param  string $url        Hub endpoint.
  78  * @param  string $postString String to POST.
  79  *
  80  * @return bool
  81  *
  82  * @throws Exception An error occurred.
  83  */
  84 function nocurl_http_post($url, $postString) {
  85     $params = array('http' => array(
  86         'method' => 'POST',
  87         'content' => $postString,
  88         'user_agent' => 'PubSubHubbub-Publisher-PHP/1.0',
  89     ));
  90
  91     $context = stream_context_create($params);
  92     $fp = @fopen($url, 'rb', false, $context);
  93     if (!$fp) {
  94         throw new Exception('Could not post to '. $url);
  95     }
  96     $response = @stream_get_contents($fp);
  97     if ($response === false) {
  98         throw new Exception('Bad response from the hub '. $url);
  99     }
 100     return $response;
 101 }