2

In Vaadin 8, the BinderBuilder::asRequired lets us define a Binder where a field is known to be required on a layout. If data is missing, the layout indicates to the user that the field needs to have data entered. This is great functionality, and smartly designed.

But using a Binder can be overkill for very small forms or dialog boxes. For one thing, we must define a data class to interact with the binder which can seem silly for a little form.

➙ Is there any other way to tap into Vaadin’s automatic handling of a required field without using a Binder?

In the Community Articles section of the manual, there is a page, Mark required fields as such. That page shows TextField as having setRequired and setRequiredError methods. But this seems incorrect. I can find no such methods on the latest TextField JavaDoc.

Basil Bourque
  • 303,325
  • 100
  • 852
  • 1,154

1 Answers1

3

But using a Binder can be overkill for very small forms or dialog boxes. For one thing, we must define a data class to interact with the binder which can seem silly for a little form.

Yes. This is somewhat true. Thus I implemented FieldBinder tool. Which makes possible to use similar validator - converter chain as with Binder (it replicates the same API for applicable parts) with single field without Bean. Also it has the same facilities to handle validation status changes, uses same way to show required value, or validation error as Binder.

https://vaadin.com/directory/component/fieldbinder

Tatu Lund
  • 9,949
  • 1
  • 12
  • 26