import { useState, useEffect } from 'react' // See: https://usehooks.com/useLocalStorage/ function useLocalStorage(key, initialValue) { const prefix = 'fs_' const [storedValue, setStoredValue] = useState(initialValue); // use this to track whether it's mounted. useful for doing other effects outside this hook const [ready, setReady] = useState(false); const setValue = (value) => { if (!ready) return null try { const valueToStore = value instanceof Function ? value(storedValue) : value setStoredValue(valueToStore) window.localStorage.setItem(prefix + key, JSON.stringify(valueToStore)) } catch (error) { console.log(error) } } // get the item from localstorage after the component has mounted. empty brackets mean it runs one time useEffect(() => { const item = window.localStorage.getItem(prefix + key) if (item) { setValue(item ? JSON.parse(item) : initialValue); } setReady(true); }, []) return [storedValue, setValue, ready] } export default useLocalStorage