How to display a message about failed afterSave?

Question

Yii

here is the method

public function afterSave($insert, $changedAttributes){
        if ($insert) {
            $parent= $this->parent_id  ? $this->parent : false;
              if($parent &&$parent->childs==false){
                   $parent->childs=true;
                    $parent->save();
               }
        }
}

The question is how can a message be displayed in case of a failed $parent->save(); Preferably fash message.

Answer 1

Using the addError method

Answer 2

ask
display
or demos.krajee.com/widget-details/alert