Firebase's Realtime Database is a cloud-hosted NoSQL database that lets you sync data between users in real time. This is extremely useful for applications that require real-time updates, such as online games, chat applications, and collaboration systems. In this chapter, we'll focus on authenticating users with Firebase.
User Authentication with Firebase
To create a secure, custom application, you will often need to authenticate your users. Firebase Authentication provides a complete and easy-to-use solution for managing user authentication. It supports a variety of authentication methods, including email/password authentication, phone authentication, Google authentication, Facebook authentication, and more.
Firebase Authentication Configuration
To get started with Firebase Authentication, you first need to create a Firebase project and connect your app to it. Once you've done that, you can enable your desired authentication methods in the Sign-in method section of the Firebase console.
Authentication by email/password
Email and password authentication is one of the most common authentication methods. To authenticate a user, you need to get the user's email address and password and pass them to the signInWithEmailAndPassword() function. If authentication succeeds, the user is authenticated and you can access the user's information through the returned User object.
Authentication by phone
Phone authentication allows users to authenticate to your application using their phone number. Firebase sends a verification code via SMS to the provided phone number. The user then enters this code into the app to authenticate. This authentication method is useful for apps that don't require a user's email address.
Google Authentication
Google authentication allows users to authenticate to your application using their Google account. To use this authentication method, you need to set up a project on Google Cloud Platform and obtain an API key. After that, you can use the signInWithGoogle() function to authenticate the user.
Facebook Authentication
Facebook authentication works similarly to Google authentication. You need to create an app on Facebook for Developers and get an App ID. You can then use the signInWithFacebook() function to authenticate the user.
Managing Authenticated Users
Once a user is authenticated, you can access the user's information through the User object. This includes user ID, email address, name and profile picture. You can also check if the user's email has been verified, change the user's password, send a verification email, and more.
Protecting data with security rules
Firebase security rules let you control who has access to your data. You can specify security rules in the Firebase console. For example, you can allow only authenticated users to read and write data, or you can allow everyone to read data but only authenticated users to write data.
Conclusion
Firebase Realtime Database and Firebase Authentication provide a powerful and flexible solution for managing real-time data and authenticating users. With these tools, you can build secure, custom applications without having to manage your own backend infrastructure.
