How to set flash message in Yii2 after denied access to controller

Question

How to set flash message in Yii2 after denied access to controller? Here is how deny access http://www.yiiframework.com/doc-2.0/yii-filters-accesscontrol.html :

public function behaviors()
{
    return [
        'access' => [
            'class' => \yii\filters\AccessControl::className(),
            'only' => ['create', 'update'],
            'rules' => [
                // deny all POST requests
                [
                    'allow' => false,
                    'verbs' => ['POST']
                ],
                // allow authenticated users
                [
                    'allow' => true,
                    'roles' => ['@'],
                ],
                // everything else is denied
            ],
        ],
    ];
}

after this it redirects to site/login. how can I make flash message there like "This section is only for registered users"?

Answer 1

Could you try adding a callback for denial? I hope this works:

public function behaviors()
{
    return [
        'access' => [
            'class' => \yii\filters\AccessControl::className(),
            'only' => ['create', 'update'],
            'rules' => [
                // deny all POST requests
                [
                    'allow' => false,
                    'verbs' => ['POST']
                ],
                // allow authenticated users
                [
                    'allow' => true,
                    'roles' => ['@'],
                ],
                // everything else is denied
            ],
            'denyCallback'  => function ($rule, $action) {
                Yii::$app->session->setFlash('error', 'This section is only for registered users.');
                Yii::$app->user->loginRequired();
            },
        ],
    ];
}

Answer 2

Also you can add denyCallback to each rule:

    [
      'allow' => false,
      'roles' => ['@'],
      'denyCallback' => function($rule, $action) {
         // callback logic
       }
    ]