ValueChangeLister of TextField

Hi
I want to update one textField when another textField is updated with some manipulation. I didn’t find much info about ValueChange event of TextField. The code will be something as follows but is is returning null pointer exception at the line yearFromAdd…, any suggestions?


@Override
    public void init(Map<String, Object> params) {
        yearFrom.addValueChangeListener((ValueChangeListener) ( value) -> {
       
                showNotification("set", NotificationType.HUMANIZED);
 
        });
    }