useControllable

The hook every salle form control is built on, and one you can reuse for your own controlled/uncontrolled components. Given the optional controlled value, a default, and an onChange, it returns a (current, set) pair that does the right thing in either mode:

val (current, set) = useControllable(value, default, onChange)

In controlled mode (value is Some) set only calls onChange — the next render’s Some carries the new value back. In uncontrolled mode (value is None) set updates internal state and calls onChange as a notification. Writing a component against this pair means its body is identical in both modes.