React how to use state in passed function - reactjs

Question

I am using React context to pass down state. When my state changes, it also changes in the child Component (console logs shows new value), but when this state is used in a function, it doesnt update there (console.log shows old value).
Do I need to rerender the function? How?
const {user, userInfo, ref} = useSession(); <-- wrapper for useContext
console.log(userInfo); <--- correct, updated value
const haalDataOp = async () => {
console.log(userInfo.enelogic); <--- old value displaying
...
}
I am using the function haalDataOp from a button (onClick)
As someone already mentioned, I could use useRef, but I dont understand why. Why does this simple example work (extracted from https://dev.to/anpos231/react-hooks-the-closure-hell-71m), and my code doesnt:
const [value, setValue] = useState(1);
const handleClick = useCallback(
() => {
setValue(value + 1)
},
[value],
);
I also tried using useCallback (with userInfo in the dep array) in my example but that doesnt do the trick.

Answer 1

const ... userInfo ... is a constant, so in a Component like following:
console.log('render', userInfo.enelogic) // different value in each render
const haalDataOp = async () => {
console.log('before', userInfo.enelogic) // correct old value
await update()
console.log('after', userInfo.enelogic) // still the same old value
}
return <button onClick={haalDataOp} />
...it would log:
render old
before old
after old
render new
...because the userInfo inside haalDataOp is a closure referencing to the value from the original render. If you need to access a mutable reference that would point to the up-to-date value from a future render instead, you can useRef:
const userInfoRef = useRef()
userInfoRef.current = userInfo
console.log('render', userInfo.enelogic) // different value in each render
const haalDataOp = async () => {
console.log('before', userInfoRef.current.enelogic) // old value
await update()
console.log('after', userInfoRef.current.enelogic) // should be new value
}
return <button onClick={haalDataOp} />
However, there might be a race condition and/or the execution of the 'after' code happens deterministically BEFORE the next render, in which case you will need to use some other trick...
I suspect that the const {ref} = useSession() is needed for exactly this situation, so please read the documentation.