Example of how to use Redux Final Form Listener OnChange

WhenFieldChanges.js

const WhenFieldChanges = ({ field, becomes, set, to }) => (
  <Field name={set} subscription={{}}>
    {(
      // No subscription. We only use Field to get to the change function
      { input: { onChange } }
    ) => (
      <OnChange name={field}>
        {value => {
          if (value === becomes) {
            onChange(to)
          }
        }}
      </OnChange>
    )}
  </Field>
)