isgdURL

isgdURL creates a shortened url using the is.gd service's API.

is.gd's API documentation is found at http://74.208.111.132/gb/is.gd/api_info.php

TODO: we can varify that the returned shorted url points correctly by getting the headers returned by a curl request to the shortened url. We should get HTTP 301 redirect header with the location parameter set to the original long URL.

use : [code] <?php anchor(isgdURL($longurl)); ?> [/code]

[code] /**

• @name isgdURL helper for Codeigniter

• @author Nathan Letsinger [email protected]

• @copyright Copyright (c) 2009, Nathan Letsinger

• @license http://www.gnu.org/copyleft/gpl.html

• creates a shortened url using is.gd's API when supplied with a url string

• WARNING:

• This function expects a well formed unencoded url and does not validate input.

• However, is.gd does validate input, and will return an error message on malformed

• urls like " Error: The URL entered was not valid." along with a 500 status code header.

• PHP REQUIREMENTS:

• This helper requires the cURL library (libcurl) to be compiled into PHP to reach is.gd

• if curl is not installed you might opt to replace curl calls with a single

• call to file_get_contents if the fopen wrappers have been enabled. However

• using that function may take significantly longer (noticibly in seconds) and

• degrade performance.

• CI REQUIREMENTS:

• Requires the xss_clean method of CI_input class to parse url output from is.gd

• if xss_clean cannot be found the function returns the original input $url.

• TERMS OF SERVICE REMINDER:

• Note that users of the is.gd API are expected to comply with TOS

• found here: http://74.208.111.132/gb/is.gd/terms.php

• @link http://us3.php.net/manual/en/intro.curl.php PHP-cURL

• @link http://74.208.111.132/gb/is.gd/api_info.php API-doc

• @link http://74.208.111.132/gb/is.gd/terms.php API-Terms-of-Service

• @uses CI_Input::xss_clean()

• @param string $url unencoded url to shrink

• @return string either the newly shrunk url or $url */ function isgdURL($url) {
  $timeout_seconds = 5; //@todo finetune timeout in seconds for your app.

   $curl_handle = curl_init('http://is.gd/api.php?longurl=' . urlencode($url));
   curl_setopt($curl_handle, CURLOPT_HTTP_VERSION , CURL_HTTP_VERSION_1_1 );
   curl_setopt($curl_handle, CURLOPT_CONNECTTIMEOUT, $timeout_seconds);
   curl_setopt($curl_handle, CURLOPT_RETURNTRANSFER, 1);
   $shrunkURL           = curl_exec($curl_handle);
   $http_response_int   = curl_getinfo($curl_handle , CURLINFO_HTTP_CODE);
  
   if (curl_errno($curl_handle))
   {
       log_message('error','curl error: ' . curl_error($curl_handle));
       return $url;
   }
   
   curl_close($curl_handle);
  
  
   /**
    * is.gd responds w/ header status code "HTTP/1.1 200 OK" if url is shortened as expected
    * and w/ "HTTP/1.1 500 Internal Server Error" if there is a problem.
    * We return the supplied url on any status code but 200 & that matches
    * the expected output pattern.
    */
  
   switch ($http_response_int)
   {
  
       case 200:
           if( ! preg_match("/^http(s?):\/\/is.gd\/[a-z0-9]+/i" , $shrunkURL))
           {
               log_message('error','Failed preg match with shrunk url ' . $shrunkURL);
               return $url;
           }
           break;
  
       case 500:
           log_message('error','500 Internal Server Error contacting is.gd api with url "' . $url . '"');
           log_message('error','is.gd api responded : ' . $shrunkURL);
           return $url;
           break;
  
       default:
           log_message('error','Response status ' . $http_response . ' contacting is.gd api with url "' . $url . '"');
           return $url;
   }
  
   $ci =& get_instance();
   return (method_exists($ci->input, 'xss_clean')) ? $ci->input->xss_clean($shrunkURL) : $url ;
  

} [/code]