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 use Shaarli\Config\ConfigManager;
  14 use Shaarli\Feed\FeedBuilder;
  15 use Shaarli\Router;
  16
  17 /**
  18  * Plugin init function - set the hub to the default appspot one.
  19  *
  20  * @param ConfigManager $conf instance.
  21  */
  22 function pubsubhubbub_init($conf)
  23 {
  24     $hub = $conf->get('plugins.PUBSUBHUB_URL');
  25     if (empty($hub)) {
  26         // Default hub.
  27         $conf->set('plugins.PUBSUBHUB_URL', 'https://pubsubhubbub.appspot.com/');
  28     }
  29 }
  30
  31
  32 /**
  33  * Render feed hook.
  34  * Adds the hub URL in ATOM and RSS feed.
  35  *
  36  * @param array         $data Template data.
  37  * @param ConfigManager $conf instance.
  38  *
  39  * @return array updated template data.
  40  */
  41 function hook_pubsubhubbub_render_feed($data, $conf)
  42 {
  43     $feedType = $data['_PAGE_'] == Router::$PAGE_FEED_RSS ? FeedBuilder::$FEED_RSS : FeedBuilder::$FEED_ATOM;
  44     $template = file_get_contents(PluginManager::$PLUGINS_PATH . '/pubsubhubbub/hub.'. $feedType .'.xml');
  45     $data['feed_plugins_header'][] = sprintf($template, $conf->get('plugins.PUBSUBHUB_URL'));
  46
  47     return $data;
  48 }
  49
  50 /**
  51  * Save link hook.
  52  * Publish to the hub when a link is saved.
  53  *
  54  * @param array         $data Template data.
  55  * @param ConfigManager $conf instance.
  56  *
  57  * @return array unaltered data.
  58  */
  59 function hook_pubsubhubbub_save_link($data, $conf)
  60 {
  61     $feeds = array(
  62         index_url($_SERVER) .'?do=atom',
  63         index_url($_SERVER) .'?do=rss',
  64     );
  65
  66     $httpPost = function_exists('curl_version') ? false : 'nocurl_http_post';
  67     try {
  68         $p = new Publisher($conf->get('plugins.PUBSUBHUB_URL'));
  69         $p->publish_update($feeds, $httpPost);
  70     } catch (Exception $e) {
  71         error_log(sprintf(t('Could not publish to PubSubHubbub: %s'), $e->getMessage()));
  72     }
  73
  74     return $data;
  75 }
  76
  77 /**
  78  * Http function used to post to the hub endpoint without cURL extension.
  79  *
  80  * @param  string $url        Hub endpoint.
  81  * @param  string $postString String to POST.
  82  *
  83  * @return bool
  84  *
  85  * @throws Exception An error occurred.
  86  */
  87 function nocurl_http_post($url, $postString)
  88 {
  89     $params = array('http' => array(
  90         'method' => 'POST',
  91         'content' => $postString,
  92         'user_agent' => 'PubSubHubbub-Publisher-PHP/1.0',
  93     ));
  94
  95     $context = stream_context_create($params);
  96     $fp = @fopen($url, 'rb', false, $context);
  97     if (!$fp) {
  98         throw new Exception(sprintf(t('Could not post to %s'), $url));
  99     }
 100     $response = @stream_get_contents($fp);
 101     if ($response === false) {
 102         throw new Exception(sprintf(t('Bad response from the hub %s'), $url));
 103     }
 104     return $response;
 105 }
 106
 107 /**
 108  * This function is never called, but contains translation calls for GNU gettext extraction.
 109  */
 110 function pubsubhubbub_dummy_translation()
 111 {
 112     // meta
 113     t('Enable PubSubHubbub feed publishing.');
 114 }