Search code examples
react-final-form

Accessing a field value in FinalForm, useField vs useFormState

I need to access a field value to trigger special logic when it changes.

I can do:

const { input: { value: myField }} = useField("myField");

// do some stuff with myField

const state = useFormState();
const myField = state.values.myField;

// do some stuff with myField

What is the preferable way ? They are not exactly equivalent, for instance, when myField is not defined, useField will return '' while useFormState will return undefined.

Solution

  • If you just want the value of one (or maybe up to 3) field(s), use useField.

    Yes, useField() gives you ''. This is to ensure that the input is controlled.