In a ComboBox initialized with values and with a value set can I do not permit null values?

what I mean is to not permit the user to delete the values in the combobox, still select one of the values in the list even when he is searching.

In practice be sure that getValue() is always != null


Well if you make the combo box required saving is not possible without a value.

you mean using a Binder ?


ok I will try, thanks

If I have for example a radio button that enabled/disabled some fields and some fields becomes required in one of the state of this radio button, how do you manage this with Binder ? You have to save the Binding object on the bean/component and use setAsRequiredEnabled(…) on this depending on the state?

some fields become required but in some state of the form, not always

I’m doing this with multiple binders that I’ve nested / stored in map and replace the sub binder everytime the “subform” changes (your radio button in this example opens a “subform”) or you can remove the bindings what you like more

what you mean with nested binders ?

Using multiple binders in a parent children relationship or just with the same hierarchy stored in a map

just to understand, you divide the bean to validate in multiple beans in a parent bean with every bean their own binder ?

You don’t have to, you can just use 1-2 properties in the bean for each binder