actionUpdate

    /**
     * Updates an existing Contact model.
     * If update is successful, the browser will be redirected to the 'view' page.
     * @param integer $id
     * @return mixed
     */
    public function actionUpdate($id)
    {
        $model = $this->findModel($id);

        if ($model->load(Yii::$app->request->post()) && $model->save()) {
            return $this->redirect(['view', 'id' => $model->id]);
        } else {
            return $this->render('update', [
                'model' => $model,
            ]);
        }
    }