Google URL Shortener PHP Class

Google has had a URL shortening domain for quite a while now but it wasn't until recently that Google exposed the URL shortening API to the public. I took a few minutes to review their API and created a very basic GoogleUrlApi class that will shorten long URLs and expand shortened URLs. The PHP The class itself is quite compact and the code should be easy to read:

// Declare the class
class GoogleUrlApi {
  
  // Constructor
  function GoogleURLAPI($key,$apiURL = 'https://www.googleapis.com/urlshortener/v1/url') {
    // Keep the API Url
    $this->apiURL = $apiURL.'?key='.$key;
  }
  
  // Shorten a URL
  function shorten($url) {
    // Send information along
    $response = $this->send($url);
    // Return the result
    return isset($response['id']) ? $response['id'] : false;
  }
  
  // Expand a URL
  function expand($url) {
    // Send information along
    $response = $this->send($url,false);
    // Return the result
    return isset($response['longUrl']) ? $response['longUrl'] : false;
  }
  
  // Send information to Google
  function send($url,$shorten = true) {
    // Create cURL
    $ch = curl_init();
    // If we're shortening a URL...
    if($shorten) {
      curl_setopt($ch,CURLOPT_URL,$this->apiURL);
      curl_setopt($ch,CURLOPT_POST,1);
      curl_setopt($ch,CURLOPT_POSTFIELDS,json_encode(array("longUrl"=>$url)));
      curl_setopt($ch,CURLOPT_HTTPHEADER,array("Content-Type: application/json"));
    }
    else {
      curl_setopt($ch,CURLOPT_URL,$this->apiURL.'&shortUrl='.$url);
    }
    curl_setopt($ch,CURLOPT_RETURNTRANSFER,1);
    // Execute the post
    $result = curl_exec($ch);
    // Close the connection
    curl_close($ch);
    // Return the result
    return json_decode($result,true);
  }    
}

The constructor requires your Google API key. A second argument may be provided to the URL of the Google API. As the API is currently in version 1, changing this URL would be more harmful than useful. The class features two main methods: shorten and expand. Each method takes the long or short URL, contacts Google, and returns its counterpart. If no counterpart is found, or the Google URL Shortener API is down, a result of false is returned, so please be sure to use your own error handling. Now let's create an instance of GoogleUrlApi to shorten and then expand a URL:

// Create instance with key
$key = 'xhjkhzkhfuh38934hfsdajkjaf';
$googer = new GoogleURLAPI($key);

// Test: Shorten a URL
$shortDWName = $googer->shorten("http://davidwalsh.name");
echo $shortDWName; // returns http://goo.gl/i002

// Test: Expand a URL
$longDWName = $googer->expand($shortDWName);
echo $longDWName; // returns http://davidwalsh.name