React Firebase Hooks

React Firebase Hooks are a set of hooks that allow developers to easily use Firebase services in their React applications. These hooks provide an easy-to-use interface for services such as Firebase Authentication, Realtime Database, Cloud Firestore, and Cloud Functions. This allows developers to focus on writing their application logic rather than worrying about the intricacies of Firebase.

Installation

To use React Firebase Hooks, you must first install it using npm:

npm install react-firebase-hooks

Authentication

One of the most common use cases for Firebase is authentication. React Firebase Hooks provides a set of hooks for Firebase Authentication:

useFirebaseAuth

This hook provides the user object from Firebase Authentication. It can be used to conditionally render components based on whether or not a user is logged in:

import { useFirebaseAuth } from 'react-firebase-hooks/auth';
import firebase from 'firebase/app';

const auth = firebase.auth();

function MyComponent() {
  const [user, loading] = useFirebaseAuth(auth);

  if (loading) {
    return <div>Loading...</div>;
  }

  return user ? (
    <div>Welcome {user.displayName}!</div>
  ) : (
    <div>Please log in.</div>
  );
}

useFirebaseAuthState

This hook provides a boolean indicating whether or not a user is logged in. This can be used to conditionally render components based on the user's authentication state:

import { useFirebaseAuthState } from 'react-firebase-hooks/auth';
import firebase from 'firebase/app';

const auth = firebase.auth();

function MyComponent() {
  const [isSignedIn, loading] = useFirebaseAuthState(auth);

  if (loading) {
    return <div>Loading...</div>;
  }

  return isSignedIn ? (
    <div>Welcome user!</div>
  ) : (
    <div>Please log in.</div>
  );
}

Realtime Database

Firebase Realtime Database allows applications to maintain real-time synchronization of data between clients. React Firebase Hooks provides a set of hooks for Realtime Database:

useFirebaseDatabase

This hook returns a reference to the Realtime Database service. It can be used to read and write data to the database:

import { useFirebaseDatabase } from 'react-firebase-hooks/database';
import firebase from 'firebase/app';

const database = firebase.database();

function MyComponent() {
  const [data, loading, error] = useFirebaseDatabase(database.ref('/path/to/data'));

  if (error) {
    return <div>Error: {error.message}</div>;
  }

  if (loading) {
    return <div>Loading...</div>;
  }

  return <div>{data}</div>;
}

useFirebaseObject

This hook returns an object representing a snapshot of a Realtime Database location. It can be used to read and write data to the database:

import { useFirebaseObject } from 'react-firebase-hooks/database';
import firebase from 'firebase/app';

const database = firebase.database();

function MyComponent() {
  const [data, loading, error] = useFirebaseObject(database.ref('/path/to/data'));

  if (error) {
    return <div>Error: {error.message}</div>;
  }

  if (loading) {
    return <div>Loading...</div>;
  }

  return <div>{data}</div>;
}

Cloud Firestore

Cloud Firestore is a NoSQL document database that provides realtime updates. React Firebase Hooks provides a set of hooks for Cloud Firestore:

useFirebaseCollection

This hook returns a query snapshot of a collection in Cloud Firestore. It can be used to read and write data to the collection:

import { useFirebaseCollection } from 'react-firebase-hooks/firestore';
import firebase from 'firebase/app';

const firestore = firebase.firestore();

function MyComponent() {
  const [data, loading, error] = useFirebaseCollection(firestore.collection('/path/to/collection'));

  if (error) {
    return <div>Error: {error.message}</div>;
  }

  if (loading) {
    return <div>Loading...</div>;
  }

  return <div>{data}</div>;
}

useFirebaseDocument

This hook returns a document snapshot from a document in Cloud Firestore. It can be used to read and write data to the document:

import { useFirebaseDocument } from 'react-firebase-hooks/firestore';
import firebase from 'firebase/app';

const firestore = firebase.firestore();

function MyComponent() {
  const [data, loading, error] = useFirebaseDocument(firestore.doc('/path/to/document'));

  if (error) {
    return <div>Error: {error.message}</div>;
  }

  if (loading) {
    return <div>Loading...</div>;
  }

  return <div>{data}</div>;
}

Cloud Functions

Cloud Functions is a serverless function platform by Firebase. React Firebase Hooks provides a set of hooks for Cloud Functions:

useFirebaseFunction

This hook returns a callable function reference. It can be used to call Cloud Functions:

import { useFirebaseFunction } from 'react-firebase-hooks/functions';
import firebase from 'firebase/app';

const functions = firebase.functions();

function MyComponent() {
  const sampleFunction = useFirebaseFunction(functions.httpsCallable('sampleFunction'));

  async function handleClick() {
    const result = await sampleFunction({ data: 'example' });
    console.log(result.data);
  }

  return <button onClick={handleClick}>Click me</button>;
}

Conclusion

React Firebase Hooks provide an easy-to-use interface for Firebase services in React applications. With these hooks, developers can more easily build applications that rely on Firebase services, while focusing on their application logic.