How to validate Vaadin 8 PasswordField?

Question

In Vaadin 7 I have PasswordField and following code:-

  PasswordField passwordField =  new PasswordField((String) processConfig.get("name"));
  passwordField.setWidth("100%");
  passwordField.addValidator(new RegexpValidator("[^\\s]*", "Whitespace is not allowed for password field"));

Recently I upgraded to Vaadin 8. Now there is compiler error no addValidator method. I know there is new Validator + Binder. But is there any way to avoid Binder and try to have my own validation?

Answer 1

This is one of the differences between Vaadin 7 and Vaadin 8 and subsequent versions like Vaadin 14 for example. In Vaadin 8 Validators are not bound to Fields, but Binder. Hence if you want to validate single field without using Binder, the correct way is to use addValueChangeListener(..) and check the value in ValueChangeEvent.