add lib/pubsubhubbub/subscriber.php

lib/pubsubhubbub/subscriber.php

@@ -0,0 +1,120 @@
+<?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 Subscriber {
+    
+    // put your google key here
+    // required if you want to use the google feed API to lookup RSS feeds
+    protected $google_key = "";
+    
+    protected $hub_url;
+    protected $callback_url;
+    protected $credentials;
+    // accepted values are "async" and "sync"
+    protected $verify = "async"; 
+    protected $verify_token;
+    protected $lease_seconds;
+    
+    // create a new Subscriber (credentials added for SuperFeedr support)
+    public function __construct($hub_url, $callback_url, $credentials = false) {
+        
+        if (!isset($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);
+            
+        if (!isset($callback_url))
+            throw new Exception('Please specify a callback');
+            
+        $this->hub_url = $hub_url;
+        $this->callback_url = $callback_url;
+        $this->credentials = $credentials;
+    }
+    
+    // $use_regexp lets you choose whether to use google AJAX feed api (faster, but cached) or a regexp to read from site
+    public function find_feed($url, $http_function = false) {
+        // using google feed API
+        $url = "http://ajax.googleapis.com/ajax/services/feed/lookup?key={$this->google_key}&v=1.0&q=".urlencode($url);
+        // fetch the content 
+        if ($http_function)
+            $response = $http_function($url);
+        else
+            $response = $this->http($url);
+
+        $result = json_decode($response, true);
+        $rss_url = $result['responseData']['url'];
+        return $rss_url;
+    }
+    
+    public function subscribe($topic_url, $http_function = false) {
+        return $this->change_subscription("subscribe", $topic_url, $http_function = false);
+    }
+    
+    public function unsubscribe($topic_url, $http_function = false) {
+        return $this->change_subscription("unsubscribe", $topic_url, $http_function = false);
+    }
+
+    // helper function since sub/unsub are handled the same way
+    private function change_subscription($mode, $topic_url, $http_function = false) {
+        if (!isset($topic_url))
+            throw new Exception('Please specify a 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);
+        
+        // set the mode subscribe/unsubscribe
+        $post_string = "hub.mode=".$mode;
+        $post_string .= "&hub.callback=".urlencode($this->callback_url);
+        $post_string .= "&hub.verify=".$this->verify;
+        $post_string .= "&hub.verify_token=".$this->verify_token;
+        $post_string .= "&hub.lease_seconds=".$this->lease_seconds;
+    
+        // append the topic url parameters
+        $post_string .= "&hub.topic=".urlencode($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 $this->http($this->hub_url,$post_string);
+    }
+    
+    // default http function that uses curl to post to the hub endpoint
+    private function http($url, $post_string) {
+        
+        // add any additional curl options here
+        $options = array(CURLOPT_URL => $url,
+                         CURLOPT_USERAGENT => "PubSubHubbub-Subscriber-PHP/1.0",
+                         CURLOPT_RETURNTRANSFER => true);
+                         
+        if ($post_string) {
+            $options[CURLOPT_POST] = true;
+            $options[CURLOPT_POSTFIELDS] = $post_string;
+        }
+                         
+        if ($this->credentials)
+            $options[CURLOPT_USERPWD] = $this->credentials;
+
+    	$ch = curl_init();
+    	curl_setopt_array($ch, $options);
+
+        $response = curl_exec($ch);
+        $info = curl_getinfo($ch);
+        
+        // all good -- anything in the 200 range 
+        if (substr($info['http_code'],0,1) == "2") {
+            return $response;
+        }
+        return false;	
+    }
+}
+
+
+?>