[php] Laravel - check if Ajax request

public function index()
{
    if(!$this->isLogin())
        return Redirect::to('login');

    if(Request::ajax()) // This is check ajax request
    {
      return $JSON;
    }

    $data = array();
    $data['records'] = $this->table->fetchAll();

    $this->setLayout(compact('data'));
}