protected function evalBinding (Expression $bindExp)
  {
    $binder = $this->getDataBinder ();
    if (!$binder) {
      _log ()->warning ("No binder is set for evaluating an expression on a " . $this->getTagName () . " component");
      return null;
    }
    try {
      /** @var Component $this */
      return $bindExp ($binder);
    }
    catch (\Exception $e) {
      self::evalError ($e, $bindExp);
    }
    catch (\Error $e) {
      self::evalError ($e, $bindExp);
    }
    return null;
  }