getSession()->setFlash('error', 'This is the message'); * - \Yii::$app->getSession()->setFlash('success', 'This is the message'); * - \Yii::$app->getSession()->setFlash('info', 'This is the message'); * * @author Alexander Makarov */ class Alert extends \yii\bootstrap\Alert { public function init() { if ($this->body = \Yii::$app->getSession()->getFlash('error')) { Html::addCssClass($this->options, 'alert-error'); } elseif ($this->body = \Yii::$app->getSession()->getFlash('success')) { Html::addCssClass($this->options, 'alert-success'); } elseif ($this->body = \Yii::$app->getSession()->getFlash('info')) { Html::addCssClass($this->options, 'alert-info'); } elseif ($this->body = \Yii::$app->getSession()->getFlash('warning')) { } else { // no message passed, no need to render widget return; } parent::init(); } }