JBZoo\Utils\Url::isAbsolute PHP Метод

    public static function isAbsolute($path)
    {
        $result = strpos($path, '//') === 0 || preg_match('#^[a-z-]{3,}:\\/\\/#i', $path);
        return $result;
    }

 /**
  * Find source in variants.
  *
  * @return array
  */
 protected function _findSource()
 {
     $path = $this->_manager->getPath();
     if ($path->isVirtual($this->_source)) {
         return $path->get($this->_source);
     }
     if (Url::isAbsolute($this->_source)) {
         return $this->_source;
     }
     $fullPath = $path->get('root:' . $this->_source);
     return $fullPath;
 }