public function addCloseButton() { $button = new HtmlButton("close-" . $this->identifier); $button->setProperties(array("class" => "close", "data-dismiss" => "alert", "aria-label" => "close")); $button->setValue('<span aria-hidden="true">×</span>'); $this->addToPropertyCtrl("class", "alert-dismissible", array("alert-dismissible")); $this->button = $button; }