import { useState, useEffect, useCallback } from 'react'; /** * Custom hook for persisting form state to localStorage * @param key - Unique key for localStorage * @param initialValue - Initial value for the state * @returns [state, setState, clearState] tuple */ export function useLocalStorage( key: string, initialValue: T ): [T, (value: T | ((prevValue: T) => T)) => void, () => void] { // State to store our value // Pass initial state function to useState so logic is only executed once const [storedValue, setStoredValue] = useState(() => { if (typeof window === 'undefined') { return initialValue; } try { // Get from local storage by key const item = window.localStorage.getItem(key); // Parse stored json or if none return initialValue return item ? JSON.parse(item) : initialValue; } catch (error) { // If error also return initialValue console.warn(`Error loading localStorage key "${key}":`, error); return initialValue; } }); // Return a wrapped version of useState's setter function that ... // ... persists the new value to localStorage. const setValue = useCallback( (value: T | ((prevValue: T) => T)) => { try { // Allow value to be a function so we have same API as useState const valueToStore = value instanceof Function ? value(storedValue) : value; // Save state setStoredValue(valueToStore); // Save to local storage if (typeof window !== 'undefined') { window.localStorage.setItem(key, JSON.stringify(valueToStore)); } } catch (error) { // A more advanced implementation would handle the error case console.error(`Error saving localStorage key "${key}":`, error); } }, [key, storedValue] ); // Function to clear the stored value const clearValue = useCallback(() => { try { setStoredValue(initialValue); if (typeof window !== 'undefined') { window.localStorage.removeItem(key); } } catch (error) { console.error(`Error clearing localStorage key "${key}":`, error); } }, [key, initialValue]); return [storedValue, setValue, clearValue]; } /** * Hook for auto-saving form state with debouncing * @param key - Unique key for localStorage * @param value - Current form value * @param delay - Debounce delay in milliseconds (default: 500ms) */ export function useAutoSave(key: string, value: T, delay = 500) { useEffect(() => { const timeoutId = setTimeout(() => { if (typeof window !== 'undefined') { try { window.localStorage.setItem(key, JSON.stringify(value)); } catch (error) { console.error(`Error auto-saving localStorage key "${key}":`, error); } } }, delay); return () => clearTimeout(timeoutId); }, [key, value, delay]); }