add experimental support for pubsubhubbub in published feed, bump config version (refs #251)

lib/pubsubhubbub/README.txt

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+This PHP library for PubSubHubbub was written by Josh Fraser (joshfraser.com) and is released under the Apache 2.0 License
+
+Usage:
+// specify which hub you want to use. in this case we'll use the demo hub on app engine.
+$hub_url = "http://pubsubhubbub.appspot.com/";
+
+// create a new pubsubhubbub publisher
+$p = new Publisher($hub_url);
+
+// specify the feed that has been updated
+$topic_url = "http://www.onlineaspect.com";
+
+// notify the hub that the specified topic_url (ATOM feed) has been updated
+// alternatively, publish_update() also accepts an array of topic urls
+if ($p->publish_update($topic_url)) {
+    echo "$topic_url was successfully published to $hub_url";
+} else {
+    echo "Ooops...";
+    print_r($p->last_response());
+}
+ 

lib/pubsubhubbub/publisher.php

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+<?php
+
+// a PHP client library for pubsubhubbub
+// as defined at http://code.google.com/p/pubsubhubbub/
+// written by Josh Fraser | joshfraser.com | josh@eventvue.com
+// Released under Apache License 2.0
+
+class Publisher {
+    
+    protected $hub_url;
+    protected $last_response;
+    
+    // create a new Publisher
+    public function __construct($hub_url) {
+        
+        if (!isset($hub_url))
+            throw new Exception('Please specify a hub url');
+        
+        if (!preg_match("|^https?://|i",$hub_url)) 
+            throw new Exception('The specified hub url does not appear to be valid: '.$hub_url);
+            
+        $this->hub_url = $hub_url;
+    }
+
+    // accepts either a single url or an array of urls
+    public function publish_update($topic_urls, $http_function = false) {
+        if (!isset($topic_urls))
+            throw new Exception('Please specify a topic url');
+        
+        // check that we're working with an array
+        if (!is_array($topic_urls)) {
+            $topic_urls = array($topic_urls);
+        }
+        
+        // set the mode to publish
+        $post_string = "hub.mode=publish";
+        // loop through each topic url 
+        foreach ($topic_urls as $topic_url) {
+
+            // lightweight check that we're actually working w/ a valid url
+            if (!preg_match("|^https?://|i",$topic_url)) 
+                throw new Exception('The specified topic url does not appear to be valid: '.$topic_url);
+            
+            // append the topic url parameters
+            $post_string .= "&hub.url=".urlencode($topic_url);
+        }
+        
+        // make the http post request and return true/false
+        // easy to over-write to use your own http function
+        if ($http_function)
+            return $http_function($this->hub_url,$post_string);
+        else
+            return $this->http_post($this->hub_url,$post_string);
+    }
+
+    // returns any error message from the latest request
+    public function last_response() {
+        return $this->last_response;
+    }
+    
+    // default http function that uses curl to post to the hub endpoint
+    private function http_post($url, $post_string) {
+        
+        // add any additional curl options here
+        $options = array(CURLOPT_URL => $url,
+                         CURLOPT_POST => true,
+                         CURLOPT_POSTFIELDS => $post_string,
+                         CURLOPT_USERAGENT => "PubSubHubbub-Publisher-PHP/1.0");
+
+    	$ch = curl_init();
+    	curl_setopt_array($ch, $options);
+
+        $response = curl_exec($ch);
+        $this->last_response = $response;
+        $info = curl_getinfo($ch);
+
+        curl_close($ch);
+        
+        // all good
+        if ($info['http_code'] == 204) 
+            return true;
+        return false;	
+    }
+}
+
+?>