React: Handling State Updates in Nested Components with useReducer - advanced patterns
I've searched everywhere and can't find a clear answer. I'm working on a personal project and I'm currently building a complex form in React using `useReducer` to manage state... The form has multiple nested components, and I'm working with an scenario where updates in one nested component are not reflecting correctly in another. I have implemented the state management like this: ```javascript import React, { useReducer } from 'react'; const initialState = { user: { name: '', email: '', }, preferences: { notifications: true, theme: 'light', }, }; const reducer = (state, action) => { switch (action.type) { case 'UPDATE_USER': return { ...state, user: { ...state.user, ...action.payload } }; case 'TOGGLE_NOTIFICATIONS': return { ...state, preferences: { ...state.preferences, notifications: !state.preferences.notifications } }; default: return state; } }; const Form = () => { const [state, dispatch] = useReducer(reducer, initialState); return ( <div> <UserForm user={state.user} dispatch={dispatch} /> <Preferences preferences={state.preferences} dispatch={dispatch} /> </div> ); }; const UserForm = ({ user, dispatch }) => { const handleChange = (e) => { const { name, value } = e.target; dispatch({ type: 'UPDATE_USER', payload: { [name]: value } }); }; return ( <div> <input type='text' name='name' value={user.name} onChange={handleChange} /> <input type='email' name='email' value={user.email} onChange={handleChange} /> </div> ); }; const Preferences = ({ preferences, dispatch }) => { return ( <div> <label> Notifications: <input type='checkbox' checked={preferences.notifications} onChange={() => dispatch({ type: 'TOGGLE_NOTIFICATIONS' })} /> </label> </div> ); }; export default Form; ``` The question arises when I update the user’s name in the `UserForm`. The other nested component, `Preferences`, fails to re-render properly, and I notice that the state does not appear to update as expected. I checked the console for errors but only see this warning: `Warning: need to perform a React state update on an unmounted component` when I navigate away from the form before it completes updating. I attempted to debug by adding `console.log(state)` within the render method of both components, and the state is indeed updating, but the UI doesn’t reflect these changes immediately. I suspect there might be an scenario with how I'm passing the dispatch function or handling the state updates. Can anyone suggest what might be going wrong? Is there a best practice I might be missing when dealing with nested state updates in React? Is there a better approach? What am I doing wrong?