protected function _url($url = null) {
		if ($url !== null) {
			return '/' . trim($url, '/');
		} elseif ($uri = $this->env('REQUEST_URI')) {
			list($uri) = explode('?', $uri, 2);
			$base = '/^' . preg_quote($this->_base, '/') . '/';
			return '/' . trim(preg_replace($base, '', $uri), '/') ?: '/';
		}
		return '/';
	}
protected function _url($url = null) {
		if ($url !== null) {
			return '/' . trim($url, '/');
		} elseif ($uri = $this->env('REQUEST_URI')) {
			list($uri) = explode('?', $uri, 2);
			$base = '/^' . preg_quote($this->_base, '/') . '/';
			return '/' . trim(preg_replace($base, '', $uri), '/') ?: '/';
		}
		return '/';
	}
protected function _url ( $ url = null ) { if ( $ url !== null ) { return '/' . trim ( $ url , '/' ) ; } elseif ( $ uri = $ this -> env ( 'REQUEST_URI' ) ) { list ( $ uri ) = explode ( '?' , $ uri , 2 ) ; $ base = '/^' . preg_quote ( $ this -> _base , '/' ) . '/' ; return '/' . trim ( preg_replace ( $ base , '' , $ uri ) , '/' ) ? : '/' ; } return '/' ; }
Extract the url from `REQUEST_URI` && `PHP_SELF` environment variables.

@param  string The base url If `null`, environment variables will be used instead.
@return string
Extract the url from REQUEST_URI && PHP_SELF environment variables .