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\Plugin\PluginManager;
  16 use Shaarli\Render\TemplatePage;
  17
  18 /**
  19  * Plugin init function - set the hub to the default appspot one.
  20  *
  21  * @param ConfigManager $conf instance.
  22  */
  23 function pubsubhubbub_init($conf)
  24 {
  25     $hub = $conf->get('plugins.PUBSUBHUB_URL');
  26     if (empty($hub)) {
  27         // Default hub.
  28         $conf->set('plugins.PUBSUBHUB_URL', 'https://pubsubhubbub.appspot.com/');
  29     }
  30 }
  31
  32
  33 /**
  34  * Render feed hook.
  35  * Adds the hub URL in ATOM and RSS feed.
  36  *
  37  * @param array         $data Template data.
  38  * @param ConfigManager $conf instance.
  39  *
  40  * @return array updated template data.
  41  */
  42 function hook_pubsubhubbub_render_feed($data, $conf)
  43 {
  44     $feedType = $data['_PAGE_'] == TemplatePage::FEED_RSS ? FeedBuilder::$FEED_RSS : FeedBuilder::$FEED_ATOM;
  45     $template = file_get_contents(PluginManager::$PLUGINS_PATH . '/pubsubhubbub/hub.' . $feedType . '.xml');
  46     $data['feed_plugins_header'][] = sprintf($template, $conf->get('plugins.PUBSUBHUB_URL'));
  47
  48     return $data;
  49 }
  50
  51 /**
  52  * Save link hook.
  53  * Publish to the hub when a link is saved.
  54  *
  55  * @param array         $data Template data.
  56  * @param ConfigManager $conf instance.
  57  *
  58  * @return array unaltered data.
  59  */
  60 function hook_pubsubhubbub_save_link($data, $conf)
  61 {
  62     $feeds = [
  63         index_url($_SERVER) . 'feed/atom',
  64         index_url($_SERVER) . 'feed/rss',
  65     ];
  66
  67     $httpPost = function_exists('curl_version') ? false : 'nocurl_http_post';
  68     try {
  69         $p = new Publisher($conf->get('plugins.PUBSUBHUB_URL'));
  70         $p->publish_update($feeds, $httpPost);
  71     } catch (Exception $e) {
  72         error_log(sprintf(t('Could not publish to PubSubHubbub: %s'), $e->getMessage()));
  73     }
  74
  75     return $data;
  76 }
  77
  78 /**
  79  * Http function used to post to the hub endpoint without cURL extension.
  80  *
  81  * @param  string $url        Hub endpoint.
  82  * @param  string $postString String to POST.
  83  *
  84  * @return bool
  85  *
  86  * @throws Exception An error occurred.
  87  */
  88 function nocurl_http_post($url, $postString)
  89 {
  90     $params = ['http' => [
  91         'method' => 'POST',
  92         'content' => $postString,
  93         'user_agent' => 'PubSubHubbub-Publisher-PHP/1.0',
  94     ]];
  95
  96     $context = stream_context_create($params);
  97     $fp = @fopen($url, 'rb', false, $context);
  98     if (!$fp) {
  99         throw new Exception(sprintf(t('Could not post to %s'), $url));
 100     }
 101     $response = @stream_get_contents($fp);
 102     if ($response === false) {
 103         throw new Exception(sprintf(t('Bad response from the hub %s'), $url));
 104     }
 105     return $response;
 106 }
 107
 108 /**
 109  * This function is never called, but contains translation calls for GNU gettext extraction.
 110  */
 111 function pubsubhubbub_dummy_translation()
 112 {
 113     // meta
 114     t('Enable PubSubHubbub feed publishing.');
 115 }