React 17: implementing Context API and Updating State in Deeply Nested Components
I'm working on a project and hit a roadblock. I'm working with a question with the React Context API when trying to update state in deeply nested components. I have a context that holds user preferences, and I want to allow components at different nesting levels to update this state. However, when I call the update function, it seems like the change is not triggering a re-render in the components that are consuming the context, especially if they are deeply nested. I'm using React 17 and the `useContext` hook. Here’s a simplified version of my context provider: ```javascript import React, { createContext, useState } from 'react'; const UserPreferencesContext = createContext(); const UserPreferencesProvider = ({ children }) => { const [preferences, setPreferences] = useState({ theme: 'light', notifications: true }); const updatePreference = (key, value) => { setPreferences(prev => ({ ...prev, [key]: value })); }; return ( <UserPreferencesContext.Provider value={{ preferences, updatePreference }}> {children} </UserPreferencesContext.Provider> ); }; export { UserPreferencesContext, UserPreferencesProvider }; ``` In a child component, I’m trying to update the theme: ```javascript import React, { useContext } from 'react'; import { UserPreferencesContext } from './UserPreferencesContext'; const ThemeSwitcher = () => { const { preferences, updatePreference } = useContext(UserPreferencesContext); const toggleTheme = () => { updatePreference('theme', preferences.theme === 'light' ? 'dark' : 'light'); }; return ( <button onClick={toggleTheme}>Switch to {preferences.theme === 'light' ? 'Dark' : 'Light'} Mode</button> ); }; export default ThemeSwitcher; ``` When I click the button to toggle the theme, the context updates, but the component does not re-render as expected. I'm not receiving any errors, but the UI does not reflect the updated preference. I've verified that the `updatePreference` function is being called and that the state in the provider is updating correctly. I've tried wrapping the tree in `React.memo` to prevent unnecessary renders, but that doesn't seem to help either. What could I be missing here? Is there a best practice for using the Context API with deep nesting that I’m overlooking? For context: I'm using Javascript on Windows. Is there a better approach?