lib/pubsubhubbub/Subscriber.php

   1 <?php
   2 /**
   3  * A PHP client library for pubsubhubbub.
   4  *
   5  * @link    http://code.google.com/p/pubsubhubbub/
   6  *
   7  * @author  Josh Fraser | joshfraser.com | josh@eventvue.com
   8  * @license Apache License 2.0
   9  */
  10 namespace Pubsubhubbub\Subscriber;
  11
  12 use InvalidArgumentException;
  13
  14 class Subscriber
  15 {
  16     /**
  17      * Put your google key here.
  18      * Required if you want to use the google feed API to lookup RSS feeds.
  19      *
  20      * @var string
  21      */
  22     protected $google_key = '';
  23
  24     /**
  25      * @var string
  26      */
  27     protected $hub_url;
  28
  29     /**
  30      * @var string
  31      */
  32     protected $callback_url;
  33
  34     /**
  35      * @var string
  36      */
  37     protected $credentials;
  38
  39     /**
  40      * @var string accepted values are "async" and "sync"
  41      */
  42     protected $verify = 'async';
  43
  44     /**
  45      * @var string
  46      */
  47     protected $verify_token;
  48
  49     /**
  50      * @var string
  51      */
  52     protected $lease_seconds;
  53
  54     /**
  55      * Create a new Subscriber (credentials added for SuperFeedr support).
  56      *
  57      * @param string $hub_url
  58      * @param string $callback_url
  59      * @param string $credentials
  60      */
  61     public function __construct($hub_url, $callback_url, $credentials = false)
  62     {
  63         if (! isset($hub_url)) {
  64             throw new InvalidArgumentException('Please specify a hub url');
  65         }
  66
  67         if (! preg_match('|^https?://|i', $hub_url)) {
  68             throw new InvalidArgumentException('The specified hub url does not appear to be valid: ' . $hub_url);
  69         }
  70
  71         if (! isset($callback_url)) {
  72             throw new InvalidArgumentException('Please specify a callback');
  73         }
  74
  75         $this->hub_url = $hub_url;
  76         $this->callback_url = $callback_url;
  77         $this->credentials = $credentials;
  78     }
  79
  80     /**
  81      * $use_regexp lets you choose whether to use google AJAX feed api (faster, but cached) or a regexp to read from site.
  82      *
  83      * @param string   $url
  84      * @param callable $http_function
  85      *
  86      * @return string
  87      */
  88     public function find_feed($url, $http_function = false)
  89     {
  90         // using google feed API
  91         $url = "http://ajax.googleapis.com/ajax/services/feed/lookup?key={$this->google_key}&v=1.0&q=" . urlencode($url);
  92         // fetch the content
  93         if ($http_function) {
  94             $response = $http_function($url);
  95         } else {
  96             $response = $this->http($url);
  97         }
  98
  99         $result = json_decode($response, true);
 100         $rss_url = $result['responseData']['url'];
 101
 102         return $rss_url;
 103     }
 104
 105     /**
 106      * Subscribe to a topic.
 107      *
 108      * @param string   $topic_url
 109      * @param callable $http_function
 110      *
 111      * @return mixed
 112      */
 113     public function subscribe($topic_url, $http_function = false)
 114     {
 115         return $this->change_subscription('subscribe', $topic_url, $http_function);
 116     }
 117
 118     /**
 119      * Unsubscribe from a topic.
 120      *
 121      * @param string   $topic_url
 122      * @param callable $http_function
 123      *
 124      * @return mixed
 125      */
 126     public function unsubscribe($topic_url, $http_function = false)
 127     {
 128         return $this->change_subscription('unsubscribe', $topic_url, $http_function);
 129     }
 130
 131     /**
 132      * Helper function since sub/unsub are handled the same way.
 133      *
 134      * @param string   $mode
 135      * @param string   $topic_url
 136      * @param callable $http_function
 137      *
 138      * @return mixed
 139      */
 140     private function change_subscription($mode, $topic_url, $http_function = false)
 141     {
 142         if (! isset($topic_url)) {
 143             throw new InvalidArgumentException('Please specify a topic url');
 144         }
 145
 146         // lightweight check that we're actually working w/ a valid url
 147         if (! preg_match('|^https?://|i', $topic_url)) {
 148             throw new InvalidArgumentException('The specified topic url does not appear to be valid: ' . $topic_url);
 149         }
 150
 151         // set the mode subscribe/unsubscribe
 152         $post_string = 'hub.mode=' . $mode;
 153         $post_string .= '&hub.callback=' . urlencode($this->callback_url);
 154         $post_string .= '&hub.verify=' . $this->verify;
 155         $post_string .= '&hub.verify_token=' . $this->verify_token;
 156         $post_string .= '&hub.lease_seconds=' . $this->lease_seconds;
 157
 158         // append the topic url parameters
 159         $post_string .= '&hub.topic=' . urlencode($topic_url);
 160
 161         // make the http post request and return true/false
 162         // easy to over-write to use your own http function
 163         if ($http_function) {
 164             return call_user_func_array($http_function, [$this->hub_url, $post_string]);
 165         }
 166
 167         return $this->http($this->hub_url, $post_string);
 168     }
 169
 170     /**
 171      * Default http function that uses curl to post to the hub endpoint.
 172      *
 173      * @param string $url
 174      * @param string $post_string
 175      *
 176      * @return mixed
 177      */
 178     private function http($url, $post_string)
 179     {
 180
 181         // add any additional curl options here
 182         $options = [
 183             CURLOPT_URL            => $url,
 184             CURLOPT_USERAGENT      => 'PubSubHubbub-Subscriber-PHP/1.0',
 185             CURLOPT_RETURNTRANSFER => true,
 186         ];
 187
 188         if ($post_string) {
 189             $options[CURLOPT_POST] = true;
 190             $options[CURLOPT_POSTFIELDS] = $post_string;
 191         }
 192
 193         if ($this->credentials) {
 194             $options[CURLOPT_USERPWD] = $this->credentials;
 195         }
 196
 197         $ch = curl_init();
 198         curl_setopt_array($ch, $options);
 199
 200         $response = curl_exec($ch);
 201         $info = curl_getinfo($ch);
 202
 203         // all good -- anything in the 200 range
 204         if (substr($info['http_code'], 0, 1) == '2') {
 205             return $response;
 206         }
 207
 208         return false;
 209     }
 210 }