React hooks: How to write variables in functional components that in class components were initialized in the constructor
Variables in functional components can be initialized using useRef
hook (read more here). Also since you only want to run the cleanup function on unmounting and not on every re-render, you should pass an empty []
as the second argument to useEffect
const MyComponent = () => {
const uppy = useRef(Uppy()
.use(Transloadit, {}))
useEffect(() => {
return () => uppy.current.close()
}, [])
return <StatusBar uppy={uppy.current} />
}