Context API vs. Redux : Which One For your Next Project

In React, handling data between different parts of your app can get tricky, especially as your project grows. This is where state management tools like Context API and Redux step in to help. But which one should you use? Context API is like having a shared whiteboard in your kitchen where everyone can see and update the shopping list. It's simple and easy to use, great for smaller projects or when you don't need super detailed tracking of changes. On the other hand, Redux is like a high-tech shopping list organizer that not only shows the list but also tracks every single change and who made it. It's perfect for big projects with lots of complex data and where you need to keep a close eye on everything.

In this article, we'll break down Context API and Redux in simple terms, so even if you're new to React, you'll understand how they work and which one might be best for your project. Let's dive in and make state management in React a breeze!

What is Redux?

Redux is an open-source JavaScript library for managing and centralizing application state. Modern web applications are represented as a complex tree of components that produce and share data called state. Redux is a pattern and library that helps developers implement complex state requirements at scale. It was developed by Dan Abramov and Andrew Clark at Facebook in 2015. Redux is written in Typescript and has cross-platform compatibility.

Components of Redux

There are three main components of Redux; Store, Actions, and Reducers.

1. Store - Store is a Javascript object that holds the state of the application.
2. Actions - Actions are the events defining the changes to the state and sending data to the Redux store.
3. Reducers - Reducers are pure functions that take a state and actions input and return a state as an output.

Features of Redux

• Single Source of Truth - The global state of the application is stored in a single store in an object tree. This feature makes debugging easier and helps persist the application’s state in development.
• State is read-only - State can only be changed by emitting an action which is a plain Javascript object describing what happened. This centralized change chain keeps the race condition problem out of sight.
• Changes are made with pure functions - To specify how the state tree is transformed by actions, you write pure reducers which are just pure functions that take the previous state and action and return a new state.

Limitations of Redux

• Boilerplate Code - Setting up stores, actions, and reducers requires a lot of boilerplate code which may pose as time-consuming for beginners.
• Performance Overhead - The performance of Redux applications reduces with applications with large data due to the necessity to copy the state each time it is updated.
• Complexity - The complexity of Redux with React increases due to the difficult learning curve of Redux for beginners.

To get started, install a React app,

1. Install Redux toolkit.

npm install @reduxjs/toolkit react-redux

2. Create Slice

import { createSlice, PayloadAction } from '@reduxjs/toolkit';

const initialState: State = {
  toppings: [‘corn’]
};

const pizzaSlice = createSlice({
  name: 'pizza',
  initialState,
  reducers: {
    addTopping: (state, action) => {
      state.toppings = [...state.toppings, action.toppings];
    },
    
  }
});

export const { addTopping } = pizzaSlice.actions;
export default pizzaSlice.reducer;

3. Create a Redux Store with the Slice

import { configureStore } from '@reduxjs/toolkit';
import pizzaReducer from './pizzaSlice';
const store = configureStore({
  reducer: {
    pizza: pizzaReducer
  }
});
export default store;

4. Create a Store for your react components and wrap your component with a Provider from the Redux Library.

import React from 'react';
import { Provider } from 'react-redux';
import store from './store';
import Pizza from './Pizza';
const App = () => {
  return (
    <Provider store={store}>
      <Pizza />
    </Provider>
  );
}
export default App;

Use Cases

Redux is a suitable choice when:

• Your application has many states that are accessed by many components.
• State management requirements are complex and require a centralized approach.
• The state of the application is updated frequently.
• The logic behind the application state is complex.

What is Context API?

The React Context API allows a React app to effectively produce global variables that can be passed around. It is a state management solution provided by React. Using it we can create what is known as a context and the context provides values like states and functions. It can be consumed by a group of components that are wrapped around the context.

Components of Context API

There are two main components of React Context; Provider and Consumer.

1. Provider - Providers are used to define and keep track of specific pieces of state. This component is responsible for providing the data that is shared across the components.
2. Consumer - Consumers are responsible for modifying the state provided by the provider.

Advantages of Context API

• Data Sharing - Ease in data sharing is one of the major advantages of Context API. You can easily share data across components without having to pass the data through each level of the component tree. Thus, a global data flow is maintained while reducing bugs.
• Alternatives for Prop Drilling - Prop drilling occurs when a component needs to access data several levels deep into the component tree. This method becomes difficult and unmanageable with a large component tree. Thus, React Context API provides a mechanism to directly pass data across components without the need to pass down the props.
• Reduced Coupling - With an alternate provided to prop drilling, data can be passed across various components thus reducing coupling and dependence of components on one another making the application more efficient.
• Centralization - Using the global state flow, data can be stored centrally and updates on this data can be done more efficiently.

Limitations of Context API

• Low Performance - With large component trees, constant updates in context value can cause unnecessary re-renders and lower the performance of the application.
• Testing - Testing for context components is more difficult as compared to components with props-based state management. Providing correct context values during testing is a difficult task and requires additional initial setup.
• No Type-Safety - The context values are not type checked thus wrong values go undetected by the compiler and may lead to runtime errors.

To get started with Context API,

1. Create a Context.

import { createContext } from 'react';

export const AppContext = createContext(“”);

2. Create a Provider for the Context.

import { useState, React } from "react";
import { AppContext } from "./AppContext";
import AppComponent from "./AppComponent";
function App() {
  const [text, setText] = useState("");
  return (
    <div>
      <AppContext.Provider value={{ text, setText }}>
        <AppComponent />
      </AppContext.Provider>
    </div>
  );
}
export default App;

3. Using Context in React Component.

import { useContext } from 'react';
import { AppContext } from './AppContext';
function AppComponent() {
  const { text, setText } = useContext(AppContext);
  return (
    <div>
      <h1>{text}</h1>
      <button onClick={() => setText('Geeks for Geeks')}>
        Click me
      </button>
    </div>
  );
}
export default AppComponent;

Use Cases

Context API is a suitable choice when:

• You want to share data or state across different components of your application and need a centralized way to access and manage data.
• Your application has nested components. In this type of application, you can avoid prop drilling using Context API.
• The state of your application needs to be changed or updated dynamically.
• The components in your application that are required to have communication are not related to the component tree.

Redux vs Context API

Conclusion

In conclusion, in this article, we went through what Redux and Context APIs are, their components, advantages, limitations, and use cases. On drawing a comparison between the two, it can be concluded that Redux can be used by experienced professionals and is more suitable with large applications for better performance. On the other hand, Context API can be used by beginners and is more suitable for small and medium-sized applications for better performance. The main difference between the two is the approach to state management. Redux uses a centralized approach with store, actions, and producers as its components, and Context API uses a decentralized approach with providers and consumers as its components.