[FIXED] Best way to implement `addValueChangeListener` for a complex Vaadin Component?

Issue

I have a rather complex Vaadin component with seven different inputs:

public class MyComponent extends VerticalLayout
    implements HasValue<ValueChangeEvent<MyPojo>, MyPojo> {

  private final ComboBox<String> _objectId = new ComboBox<>();
  private final TextField _accountId = new TextField();
  private final TextField _personId = new TextField();
  private final DatePicker _startDate = new DatePicker();
  private final DatePicker _endDate = new DatePicker();
  private final IntegerField _age = new IntegerField();
  private final NumberField _amount = new NumberField();

  private final Binder<MyPojo> _binder = new Binder<>();

  // more implementation ...
}

Because of the implemented interface I also need to implement Registration addValueChangeListener(ValueChangeListener<? super ValueChangeEvent<MyPojo>> listener) What is the best way to implement this? Is there some automation or do I need to do this by hand, e.g. linking my basic input fields method addValueChangeListener to the complex ValueChangeListener<? super ValueChangeEvent<MyPojo>>? Or could I somehow use the _binder for that?

Solution

Rather than directly implementing the HasValue interface, I would recommend one of the abstract classes that help you with all the nitty gritty details.

In your case, that might be either AbstractCompositeField if you want to have full control over the visual representation or CustomField if you Vaadin to handle things like an input label.

Answered By - Leif Åstrand