@firebase/app-compat

What is @firebase/app-compat?

The @firebase/app-compat package is a compatibility layer for Firebase that allows developers to use the Firebase SDK with an API surface that is compatible with the older 'firebase' npm package (version 8 and below). It enables developers to upgrade to the modular Firebase SDK (version 9 and above) without having to refactor all of their existing code that was written using the older syntax.

What are @firebase/app-compat's main functionalities?

Initialization

This code initializes a Firebase app instance using the older, non-modular syntax. It is used to set up the Firebase context for further interactions with Firebase services.

const firebase = require('@firebase/app-compat');
const app = firebase.initializeApp({ apiKey: 'API_KEY', authDomain: 'PROJECT_ID.firebaseapp.com', projectId: 'PROJECT_ID' });

Authentication

This code demonstrates how to sign in a user with an email and password using Firebase Authentication. It uses the older syntax for ease of use with existing codebases.

const firebase = require('@firebase/app-compat');
const auth = firebase.auth();
auth.signInWithEmailAndPassword('[e-mail]', 'password').then((userCredential) => {
  // Handle successful authentication
}).catch((error) => {
  // Handle errors
});

Realtime Database

This code snippet shows how to listen for real-time updates from the Firebase Realtime Database at a specific path. It uses the traditional Firebase syntax.

const firebase = require('@firebase/app-compat');
const database = firebase.database();
database.ref('path/to/data').on('value', (snapshot) => {
  const data = snapshot.val();
  // Use the data
});

Firestore

This code sample demonstrates how to retrieve a document from a Firestore collection using the older Firebase syntax. It is useful for developers who have existing Firestore interactions written in the non-modular style.

const firebase = require('@firebase/app-compat');
const firestore = firebase.firestore();
firestore.collection('users').doc('user_id').get().then((doc) => {
  if (doc.exists) {
    const user = doc.data();
    // Use the user data
  }
}).catch((error) => {
  // Handle errors
});

Other packages similar to @firebase/app-compat

firebase

The 'firebase' package is the traditional, non-modular SDK for Firebase. It provides a similar API surface to @firebase/app-compat but is designed for use with Firebase SDK versions 8 and below. Developers using this package would not have access to the tree-shaking and modular features of the newer Firebase SDK.

react-firebase-hooks

The 'react-firebase-hooks' package provides a set of reusable React hooks for Firebase. It simplifies the process of connecting a React application to Firebase services. While it offers a different approach by leveraging React's hooks, it provides similar functionalities for authentication, database, and firestore interactions.

@angular/fire

The '@angular/fire' package is the official library for Firebase and Angular integration. It provides services and utilities to connect Angular applications with Firebase features. Like @firebase/app-compat, it abstracts Firebase interactions but is specifically tailored for Angular applications.

README

@firebase/app-compat

This is the compat package that recreates the v7 APIs.

This package is not intended for direct usage, and should only be used via the officially supported firebase package.