POST with cURL but fallback to fopen

Request.php

<?php

class Request {

  /**
   * do_post
   * POST request
   *
   * @access public
   * @param string $url - url
   * @param array $data - post data
   * @return string
   */
  
  public function do_post($url, $data = array()) {
  
      if($this->has_curl()) {
  
          return $this->do_post_curl($url, $data);
  
      } else {
  
          return $this->do_post_fopen($url, $data);
  
      }
  
  }
  
  /**
   * has_curl
   * Does the server have the curl extension ?
   *
   * @access protected
   * @return boolean
   */
  
  protected function has_curl() {
  
      return function_exists('curl_init');
  
  }
  
  /**
   * do_post_curl
   * POST request with curl
   *
   * @access protected
   * @param string $url - url
   * @param array $data - post data
   * @return string
   */
  
  protected function do_post_curl($url, $data = array()) {
  
      $ch = curl_init();
  
      curl_setopt($ch, CURLOPT_URL, $url);
      curl_setopt($ch, CURLOPT_POST, count($data));
      curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($data));
      curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
  
      $contents = curl_exec($ch);
      curl_close($ch);
  
      return $contents;
  
  }
  
  /**
   * do_post_fopen
   * POST request with fopen
   *
   * @access protected
   * @param string $url - url
   * @param array $data - post data
   * @return string
   */
  
  protected function do_post_fopen($url, $data = array()) {
  
      $stream = fopen($url, 'r', false, stream_context_create(array(
  
          'http' => array(
  
              'method' => 'POST',
              'header' => 'Content-type: application/x-www-form-urlencoded',
              'content' => http_build_query(
  
                  $data
  
              )
  
          )
  
      )));
  
      $contents = stream_get_contents($stream);
      fclose($stream);
  
      return $contents;
  
  }

}