final function run ($onlyContent = false)
  {
    if (!$this->context)
      throw new ComponentException($this, self::ERR_NO_CONTEXT);

    if ($this->isVisible ()) {
      $this->preRun ();
      //---- Rendering code ----
      $this->preRender ();
      if ($onlyContent)
        $this->runChildren ();
      else $this->render ();
      $this->postRender ();
      //---- /Rendering code ----
      $this->afterRender ();
    }
  }