Using yiiActiveForm with safe validator

I have basic yii base model that only has 1 attribute and 1 rule with this attribute. That rule is ‘safe’.
The problem is - when I’m trying to access this form’s attributes‘yiiActiveForm’).attributes - there are none. When I’m changing attributes’s rule to string or something, it shows on the attributes list.
Can someone explain to me why this happens and is it possible to not have any rules for field and still access them from activeform attributes?