How to prevent “null” text in Binder using withConverter method on Vaadin

Question

How to prevent show text "null" when using Binder withConverter method

    TextField id = new TextField("Id");
    TextField name = new TextField("Name");

        Binder<Customer> b = new Binder<>();

        b.forField(id)
                .withConverter(Integer::valueOf, String::valueOf, "Invalid")
                .bind(Customer::getId, Customer::setId);
        b.forField(name)
                .bind(Customer::getName, Customer::setName);
        b.readBean(customer);

And the result is it:

How do the conversion without losing the validation type?

You could do `id -> id == null ? "" : String.valueOf(id)` instead of just `String::valueOf`. — Steffen Harbich, Sep 28 '17 at 17:10
Oh, you need to exchange the lambda parameter name because you already have a variable named "id". So try: `cid -> cid == null ? "" : String.valueOf(cid) ` — Steffen Harbich, Sep 29 '17 at 06:26
The problem doing this `cid -> cid == null ? "" : String.valueOf(cid)` is I'm lost my validation type. — Carlos Laspina, Sep 30 '17 at 02:50
@Shirkam using `TextField#setNullRepresentation` works in conjuntion with `.withValidator(new IntegerRangeValidator("Value must be greater than 0", 1, null))` because with `null` value in `maxValue` means for no limit — Carlos Laspina, Sep 30 '17 at 02:56

Carlos Laspina · Accepted Answer · 2017-09-30T03:03:04.033

Finally, I found a solution using the vaadin API, thanks for the help @Shirkam

    b.forField(id)
            .withConverter(Integer::valueOf, String::valueOf, "Invalid")
            .withNullRepresentation(0)
            .withValidator(new IntegerRangeValidator("Value must be greater than 0 ", 1, null))
            .bind(Customer::getId, Customer::setId);
    b.forField(name)
            .bind(Customer::getName, Customer::setName);
    b.readBean(customer);

How to prevent “null” text in Binder using withConverter method on Vaadin

1 Answers1