Unlock the Power of React Native: A Step-by-Step Guide to User Authentication
React Native has revolutionized the world of mobile app development, allowing developers to create complex applications without requiring in-depth knowledge of Android or iOS. One of the most critical aspects of app development is user authentication, and React Native provides a unique opportunity to reuse web app code to build a mobile app. But how do you implement authentication in React Native?
The Challenge of Custom Authentication Systems
Many organizations have custom authentication systems that require integration with mobile apps. React Native, like React, is unopinionated, leaving developers with numerous decisions to make when implementing complex functionality. To overcome this challenge, we’ll build a demo application that showcases user authentication using JSON Web Tokens (JWT).
What is a JSON Web Token (JWT)?
In simple terms, a JWT is a secure way to exchange information between parties using the JSON format. After successful authentication, we receive two tokens: an access token and a refresh token. The access token is sent with every authenticated request, while the refresh token is used to obtain a new access token when the existing one expires.
The Demo Application
Our demo app has a single feature: displaying a random picture of a cat. To access this feature, users must be authenticated. We’ll use a backend implemented with Express and MongoDB, which exposes four API endpoints: register, login, refreshToken, and cat.
Implementing Authentication in React Native
To manage the authentication state, we’ll use the Context API and react-native-keychain to persist tokens securely. We’ll also use axios to make HTTP requests and interceptors to send the access token in the Authorization header. The axios-auth-refresh package will handle token refreshment and retry failed requests.
The Authentication Flow
When the app launches, we’ll check for tokens in the Keychain. If none exist, we’ll render the Login screen. Otherwise, we’ll display the Dashboard. The Login component will call the API with the public instance of Axios, and upon successful login, we’ll save the access and refresh tokens into the Keychain.
Taking it to the Next Level
While our demo app provides a solid foundation for user authentication, there are many ways to improve it. We can add navigation, enhance error handling, and optimize API requests. With React Native, the possibilities are endless.
Streamline Your Development Process with LogRocket
LogRocket is a powerful monitoring solution that helps you recreate issues instantly, prioritize bugs, and understand performance in your React Native apps. Try LogRocket for free and take your development process to the next level.