6 files changed, 126 insertions, 1 deletions

diff --git a/plugins/markdown/markdown.meta b/plugins/markdown/markdown.meta
index 8df2ed0b..322856ea 100644
--- a/plugins/markdown/markdown.meta
+++ b/plugins/markdown/markdown.meta
@@ -1,4 +1,4 @@
 description="Render shaare description with Markdown syntax.<br><strong>Warning</strong>:
-If your shaared descriptions containing HTML tags before enabling the markdown plugin,
+If your shaared descriptions contained HTML tags before enabling the markdown plugin,
 enabling it might break your page.
 See the <a href=\"https://github.com/shaarli/Shaarli/tree/master/plugins/markdown#html-rendering\">README</a>."
diff --git a/plugins/pubsubhubbub/README.md b/plugins/pubsubhubbub/README.md
new file mode 100644
index 00000000..3a65492a
--- /dev/null
+++ b/plugins/pubsubhubbub/README.md
@@ -0,0 +1,20 @@
+# PubSubHubbub plugin
+
+Enable this plugin to notify a Hub everytime you add or edit a link.
+ 
+This allow hub subcribers to receive update notifications in real time,
+which is useful for feed syndication service which supports PubSubHubbub.
+
+## Public Hub
+
+By default, Shaarli will use [Google's public hub](http://pubsubhubbub.appspot.com/).
+
+[Here](https://github.com/pubsubhubbub/PubSubHubbub/wiki/Hubs) is a list of public hubs.
+
+You can also host your own PubSubHubbub server implementation, such as [phubb](https://github.com/cweiske/phubb).
+
+## cURL
+
+While there is a fallback function to notify the hub, it's recommended that
+you have PHP cURL extension enabled to use this plugin.
+
diff --git a/plugins/pubsubhubbub/hub.atom.xml b/plugins/pubsubhubbub/hub.atom.xml
new file mode 100644
index 00000000..24d93d3e
--- /dev/null
+++ b/plugins/pubsubhubbub/hub.atom.xml
@@ -0,0 +1 @@
+<link rel="hub" href="%s" />
\ No newline at end of file
diff --git a/plugins/pubsubhubbub/hub.rss.xml b/plugins/pubsubhubbub/hub.rss.xml
new file mode 100644
index 00000000..27bf67a6
--- /dev/null
+++ b/plugins/pubsubhubbub/hub.rss.xml
@@ -0,0 +1 @@
+<atom:link rel="hub" href="%s" />
\ No newline at end of file
diff --git a/plugins/pubsubhubbub/pubsubhubbub.meta b/plugins/pubsubhubbub/pubsubhubbub.meta
new file mode 100644
index 00000000..289f5cdb
--- /dev/null
+++ b/plugins/pubsubhubbub/pubsubhubbub.meta
@@ -0,0 +1,2 @@
+description="Enable PubSubHubbub feed publishing."
+parameters="PUBSUBHUB_URL"
diff --git a/plugins/pubsubhubbub/pubsubhubbub.php b/plugins/pubsubhubbub/pubsubhubbub.php
new file mode 100644
index 00000000..03b6757b
--- /dev/null
+++ b/plugins/pubsubhubbub/pubsubhubbub.php
@@ -0,0 +1,101 @@
+<?php
+
+/**
+ * PubSubHubbub plugin.
+ *
+ * PubSub is a protocol which fasten up RSS fetching:
+ *   - Every time a new link is posted, Shaarli notify the hub.
+ *   - The hub notify all feed subscribers that a new link has been posted.
+ *   - Subscribers retrieve the new link. 
+ */
+
+use pubsubhubbub\publisher\Publisher;
+
+/**
+ * Plugin init function - set the hub to the default appspot one.
+ *
+ * @param ConfigManager $conf instance.
+ */
+function pubsubhubbub_init($conf)
+{
+    $hub = $conf->get('plugins.PUBSUBHUB_URL');
+    if (empty($hub)) {
+        // Default hub.
+        $conf->set('plugins.PUBSUBHUB_URL', 'https://pubsubhubbub.appspot.com/');
+    }
+}
+
+
+/**
+ * Render feed hook.
+ * Adds the hub URL in ATOM and RSS feed.
+ *
+ * @param array         $data Template data.
+ * @param ConfigManager $conf instance.
+ *
+ * @return array updated template data.
+ */
+function hook_pubsubhubbub_render_feed($data, $conf)
+{
+    $feedType = $data['_PAGE_'] == Router::$PAGE_FEED_RSS ? FeedBuilder::$FEED_RSS : FeedBuilder::$FEED_ATOM;
+    $template = file_get_contents(PluginManager::$PLUGINS_PATH . '/pubsubhubbub/hub.'. $feedType .'.xml');
+    $data['feed_plugins_header'][] = sprintf($template, $conf->get('plugins.PUBSUBHUB_URL'));
+
+    return $data;
+}
+
+/**
+ * Save link hook.
+ * Publish to the hub when a link is saved.
+ *
+ * @param array         $data Template data.
+ * @param ConfigManager $conf instance.
+ *
+ * @return array unaltered data.
+ */
+function hook_pubsubhubbub_save_link($data, $conf)
+{
+    $feeds = array(
+        index_url($_SERVER) .'?do=atom',
+        index_url($_SERVER) .'?do=rss',
+    );
+
+    $httpPost = function_exists('curl_version') ? false : 'nocurl_http_post';
+    try {
+        $p = new Publisher($conf->get('plugins.PUBSUBHUB_URL'));
+        $p->publish_update($feeds, $httpPost);
+    } catch (Exception $e) {
+        error_log('Could not publish to PubSubHubbub: ' . $e->getMessage());
+    }
+
+    return $data;
+}
+
+/**
+ * Http function used to post to the hub endpoint without cURL extension.
+ *
+ * @param  string $url        Hub endpoint.
+ * @param  string $postString String to POST.
+ *
+ * @return bool
+ *
+ * @throws Exception An error occurred.
+ */
+function nocurl_http_post($url, $postString) {
+    $params = array('http' => array(
+        'method' => 'POST',
+        'content' => $postString,
+        'user_agent' => 'PubSubHubbub-Publisher-PHP/1.0',
+    ));
+
+    $context = stream_context_create($params);
+    $fp = @fopen($url, 'rb', false, $context);
+    if (!$fp) {
+        throw new Exception('Could not post to '. $url);
+    }
+    $response = @stream_get_contents($fp);
+    if ($response === false) {
+        throw new Exception('Bad response from the hub '. $url);
+    }
+    return $response;
+}