Timber\URLHelper::is_absolute PHP Method

    public static function is_absolute($path)
    {
        return (bool) strstr($path, 'http');
    }

 /**
  * Takes in an URL and breaks it into components,
  * that will then be used in the different steps of image processing.
  * The image is expected to be either part of a theme, plugin, or an upload.
  *
  * @param  string $url an URL (absolute or relative) pointing to an image
  * @return array       an array (see keys in code below)
  */
 private static function analyze_url($url)
 {
     $result = array('url' => $url, 'absolute' => URLHelper::is_absolute($url), 'base' => 0, 'subdir' => '', 'filename' => '', 'extension' => '', 'basename' => '');
     $upload_dir = wp_upload_dir();
     $tmp = $url;
     if (0 === strpos($tmp, ABSPATH)) {
         // we've been given a dir, not an url
         $result['absolute'] = true;
         if (0 === strpos($tmp, $upload_dir['basedir'])) {
             $result['base'] = self::BASE_UPLOADS;
             // upload based
             $tmp = str_replace($upload_dir['basedir'], '', $tmp);
         }
         if (0 === strpos($tmp, WP_CONTENT_DIR)) {
             $result['base'] = self::BASE_CONTENT;
             // content based
             $tmp = str_replace(WP_CONTENT_DIR, '', $tmp);
         }
     } else {
         if (!$result['absolute']) {
             $tmp = home_url() . $tmp;
         }
         if (0 === strpos($tmp, $upload_dir['baseurl'])) {
             $result['base'] = self::BASE_UPLOADS;
             // upload based
             $tmp = str_replace($upload_dir['baseurl'], '', $tmp);
         }
         if (0 === strpos($tmp, content_url())) {
             $result['base'] = self::BASE_CONTENT;
             // content-based
             $tmp = str_replace(content_url(), '', $tmp);
         }
     }
     $parts = pathinfo($tmp);
     $result['subdir'] = $parts['dirname'] === '/' ? '' : $parts['dirname'];
     $result['filename'] = $parts['filename'];
     $result['extension'] = strtolower($parts['extension']);
     $result['basename'] = $parts['basename'];
     // todo filename
     return $result;
 }