How to Build a Real-time Chat App with ReactJS and Firebase

How to Build a Real-time Chat App with ReactJS and Firebase

In this article, I'm going to show you how to build a real-time chat app using React.js and Firebase.

In this app, we will allow the user to log in with their Google account using Firebase's Google sign-in Authentication. We will also store and retrieve all the chatroom messages using Firebase's Cloud Firestore.

Prerequisites

You should have Node.js installed on your system. You should also have intermediate knowledge of CSS, JavaScript, and Reactjs. Finally, you should know how to use the command terminal. You do not need to know how to use Firebase.

What is Firebase?

Firebase is a Backend-as-a-Service (Baas). It is a Google-backed app development platform that allows developers to build iOS, Android, and web apps.

It provides tools for tracking analytics, reporting and fixing app crashes, and creating marketing and product experiments. These help developers develop quality apps, grow their user base, and make a profit.

We will be using two of their tools: Firebase Authentication and Cloud Firestore.

Firebase Authentication

Firebase Authentication (SDK) is a Firebase tool that supports different authentication methods like passwords, phone numbers, Google, Facebook, Twitter, Github, and more. In this app, we will be using Google sign-in Authentication.

Cloud Firestore

Cloud Firestore is a cloud-based NoSQL database server for storing and syncing data. It stores data in documents as key-value pairs, and the documents are organized into collections.

The documents can also have sub-collections, allowing you to nest collections within collections. The data is also synchronized automatically among all devices listening for them.

Now that you have an idea of how Firebase and Cloud Firestore work, let's build our app

How to Create Our React App

You can create your React app by running the code in your terminal,?npx create-react-app react-chat, to create it. Here,?react-chat?is the name of the app. Then you can run?npm install firebase react-firebase-hooks?to install?firebase?and?react-firebase-hooks.


Your?src?folder now contains the following:

  • a components folder with a?NavBar?component having the?Google sign-in?and?Sign Out?button,
  • a?Welcome?component that will be visible to the user not signed in,
  • a?Chatbox?component that will be visible only when the user is signed in,
  • the?Message?component for displaying a user’s message, and
  • a?SendMessage?component so the user can input and send in their messages.

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It also has:

  • an?img?folder where the Google Sign-in image for the Sign-in button is stored,
  • an?App.css?file with the prewritten CSS codes,
  • the new?App.js?file with all our components imported into it,
  • and the?index.js?file.

Run?npm start?to view the app in the browser. Our app should look like this:

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Our React app

Now let's create a Firebase account and set up our Firebase project.

How to Set Up the Firebase Project

If you do not have a?Firebase?account already, you can open one using your Gmail (you can only use?google mail). On the landing page, click on?Get started?and then,?Add project.

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How to setup a Firebase project

Fill out the?Create a project?form by providing a project name. If you want Google Analytics enabled for your project, leave it enabled. Otherwise, disable it. After that, click on?Create project.

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Create a project

Once created, click on?Continue.

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What you'll see while Firebase is creating your project.

Choose the type of app where you want to add Firebase. For this article, we chose the code icon because we are building a web app.

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Choose the type of app to which you want to add Firestore

Enter a nickname for your app and click on?Register app.

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Register your app

Then select?npm,?copy the code snippet below it (we will be using it later), and click?Continue to console.

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Code snippet


How to Set Up Firebase Authentication

To set up Firebase Authentication, go to the menu on the left side of the screen, click on?Build, and select?Authentication?from the dropdown.

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Select authentication from the dropdown

Click on?Get started?and select?Google?in the?Sign-in method's?tab.

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Choose your authentication sign-in method

Enable?Google, choose your?Project support email, and click?Save.

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How to Set Up Cloud Firestore

Again, go to the menu on the left side of the screen. Click on?Build?and select?Firestore Database?from the dropdown. Then click on?Create database?and fill out the form.

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Setting up Cloud Firestore

Select which mode you want your database to run, production or test.

Test mode means that any client will have read/write access to your database for 30 days. Production mode means that no one will have read/write access to your database. You will have to edit your rules to grant access to specific clients.

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Chose test mode or production mode (we choose production mode).

Select?production mode?and click?Next.

Select a location where you want your Firestore to be stored and click?Enable. It will default to the location closest to you.

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Set a location (default is the location closest to you)

Next up, we edit our rules. Click on the?Rules?tab and edit the rules,

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Edit the rules through the Rules tab
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Rule to be replaced

Replace the current rule with the code below and click on?Publish.

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read: if true;
      allow create, update, delete, write: if request.auth != null;
    }
  }
}        

They?allow read: if true;?means that anyone can read your database. They?allow create, update, delete, write: if request.auth != null;?means only authenticated clients can create, update, delete, and write to your database.

You can either start to add/create a collection in your database or create one automatically in your React app, which we will do later. If you want to create a collection in Cloud Firestore, go back to the data tab by clicking?Data?beside?Rules?and then click on?Add Collection.

Enter the collection’s name, for example “messages”, and click?Next.

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Start a collection in Firestore

Now create a?document?for the Collection.

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Creating a document for the collection

You can either click?Auto_ID?to generate an id for the doc or enter one yourself.

After that, create the key-value pairs of the Document. The?Field?input represents the key name, the?Type?defines what type of data it is (string, number, timesStamp, and so on), and the?Value?is the value of the key.

You can also add more documents by clicking the plus sign, otherwise, click?Save?to save your collection.

Our Firebase project is set. Let's go back to our React app.

How to Configure Firebase in React

In our?src?folder, create a file called?firebase.js?and paste the code we had copied into it.

Let's also import the?getAuth?and?getFirestore?services from Firebase's?auth?and?firestore?libraries, respectively, and export them. You can learn more about Firebase's available libraries from their?documentation.

Our Firebase config should look like this:

// Import the functions you need from the SDKs you need
import { initializeApp } from "firebase/app";
// TODO: Add SDKs for Firebase products that you want to use
// https://firebase.google.com/docs/web/setup#available-libraries
import { getAuth } from "firebase/auth";
import { getFirestore } from "firebase/firestore";

// Your web app's Firebase configuration
// For Firebase JS SDK v7.20.0 and later, measurementId is optional
const firebaseConfig = {
  apiKey: REACT_APP_API_KEY_GOES_HERE,
  authDomain: REACT_APP_AUTH_DOMAIN_GOES_HERE,
  projectId: REACT_APP_PROJECT_ID_GOES_HERE,
  storageBucket: REACT_APP_STORAGE_BUCKET_GOES_HERE,
  messagingSenderId: REACT_APP_MESSSAGING_SENDER_ID_GOES_HERE,
  appId: REACT_APP_APP_ID_GOES_HERE,
};

// Initialize Firebase
const app = initializeApp(firebaseConfig);
export const auth = getAuth(app);
export const db = getFirestore(app);        

How to Implement Firebase into our React App

How to Authenticate Users with Their Google Account

We want our users to have access to the chatroom and send messages if logged in. They should see the welcome page if they are not. They should also see the Sign Out button if logged in and the Google Sign-in button if not.

This authentication will be handed within our NavBar component, which holds our sign-in and sign-out buttons.

In our?NavBar?component, we currently import our Google sign-in image and store it as a const called?GoogleSignin. We also have a state called?user?set to false, a?googleSignIn?function which sets the user state to?true, and a?signOut?function which sets the user state to?false.

We also have a?nav?element with an?h1?tag representing our app's title and two buttons rendered conditionally based on the user's state.

import React, { useState } from "react";
import GoogleSignin from "../img/btn_google_signin_dark_pressed_web.png";

const NavBar = () => {
  const [user, setUser] = useState(false);
  const googleSignIn = () => {
    setUser(true);
  };
  const signOut = () => {
    setUser(false);
  };
  return (
    <nav className="nav-bar">
      <h1>React Chat</h1>
      {user ? (
        <button onClick ={signOut} className="sign-out" type="button">
          Sign Out
        </button>
      ) : (
        <button className="sign-in">
          <img
            onClick ={googleSignIn}
            src={GoogleSignin}
            alt="sign in with google"
            type="button"
          />
        </button>
      )}
    </nav>
  );
};
export default NavBar;        

Let's make changes to the?NavBar?component. Import the following:

import { auth } from "../firebase";
import { useAuthState } from "react-firebase-hooks/auth";
import { GoogleAuthProvider, signInWithRedirect } from "firebase/auth";        

Replace the user state with the code below:

const [user] = useAuthState(auth);

And edit the googleSignIn and signOut functions:

const googleSignIn = () => {
  const provider = new GoogleAuthProvider();
  signInWithRedirect(auth, provider);
};
const signOut = () => {
  auth.signOut();
};        

The?useAuthState?function gets triggered when the user signs in or out, allowing us access to the user’s details. Currently, the user state is?null. Once they are logged in, the user state will change to the data provided by the authentication method – in this case, Google.

In the?googleSignIn?function, we let Firebase know that the user wants to sign in with Google using the?GoogleAuthProvider(). It also redirects them to Google’s sign-in page.

After the user successfully signs in, their data is saved in?auth, and the user is redirected to our app. The?signOut?function clears the auth data, returning it to?null. The new user state also determines which authentication buttons are rendered to the user.

Let's also add authentication to our?App.js?file. Import the following:

import { auth } from "./firebase";
import { useAuthState } from "react-firebase-hooks/auth";        

Add the new user state so we can use it to render the?Welcome?component if the user is not logged in or the?Chatbox?component if the user is logged in.

const [user] = useAuthState(auth);        

The final code looks like this:

import { auth } from "./firebase";
import { useAuthState } from "react-firebase-hooks/auth";
import "./App.css";
import NavBar from "./components/NavBar";
import ChatBox from "./components/ChatBox";
import Welcome from "./components/Welcome";

function App() {
  const [user] = useAuthState(auth);
  return (
    <div className="App">
      <NavBar />
      {!user ? <Welcome /> : <ChatBox />}
    </div>
  );
}
export default App;        

Testing our new sign-in and sign-out functions, we see the following:

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App demo

Now let's do the same for our?Welcome?Component, which currently has the following code:

import React from "react";
import GoogleSignin from "../img/btn_google_signin_dark_pressed_web.png";

const Welcome = () => {
  const googleSignIn = () => {};

  return (
    <main className="welcome">
      <h2>Welcome to React Chat.</h2>
      <img src="/logo512.png" alt="ReactJs logo" width={50} height={50} />
      <p>Sign in with Google to chat with with your fellow React Developers.</p>
      <button className="sign-in">
        <img
          onClick ={googleSignIn}
          src={GoogleSignin}
          alt="sign in with google"
          type="button"
        />
      </button>
    </main>
  );
};
export default Welcome;        

We import the following:

import { auth } from "../firebase";
import { GoogleAuthProvider, signInWithRedirect } from "firebase/auth";        

and also edit the googleSignIn function:

const googleSignIn = () => {
    const provider = new GoogleAuthProvider();
    signInWithRedirect(auth, provider);
};        

Now we can also log in from the second Sign in button:

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Updated app demo

How to Send and Store Messages in Firebase

Currently, we are displaying a dummy message from our?Message?Component, and the?Send?button also does not perform any action. When the user inputs a message and hit the?Send?button, we want the message to be seen immediately in the chatroom.

With our current?SendMessage?component having the code below, let's edit it:

import React from "react";

const SendMessage = () => {
  return (
    <form className="send-message">
      <label htmlFor="messageInput" hidden>
        Enter Message
      </label>
      <input
        id="messageInput"
        name="messageInput"
        type="text"
        className="form-input__input"
        placeholder="type message..."
      />
      <button type="submit">Send</button>
    </form>
  );
};
export default SendMessage;        

First, we import?useState?from React,?auth?and?db?from our firebase configuration file, and?addDoc,?collection?and?serverTimestamp?from the Firestore library.

import React, { useState } from "react";
import { auth, db } from "../firebase";
import { addDoc, collection, serverTimestamp } from "firebase/firestore";        

We create a state called?message?which is initially set to an empty string and passed as a value to the?input?tag. An?onChange?function is also added to the input, which sets the?message?state to whatever the user types in.

const SendMessage = () => {
  const [message, setMessage] = useState("");
    
  return (
    <form className="send-message">
      <input
        ...
        value={message}
        onChange ={(e) => setMessage(e.target.value)}
      />
      <button type="submit">Send</button>
    </form>
  );
};        

We also create a function called?sendMessage, and we add an?onSubmit?attribute to our form, which runs the?sendMessage?function when the user clicks on?Send. Note that the button must have?type="submit"?for the?onSubmit?attribute to work.

 const sendMessage = async (event) => {
    event.preventDefault();
    if (message.trim() === "") {
      alert("Enter valid message");
      return;
    }
    const { uid, displayName, photoURL } = auth.currentUser;
    await addDoc(collection(db, "messages"), {
      text: message,
      name: displayName,
      avatar: photoURL,
      createdAt: serverTimestamp(),
      uid,
    });
    setMessage("");
  };
  
  return (
    <form onSubmit ={(event) => sendMessage(event)} className="send-message">
...        

The?sendMessage?function is an async function. It first checks if the user is trying to send an empty string or whitespace as a message and alerts the user.

If the message is not an empty string, it gets the user’s?uid,?displayName, and?photoURL?from the?auth?data provided when they log in. This corresponds to the user’s?unique id,?full name, and?photo URL, respectively.

Once that is done,?it then uses the?addDoc()?to create a?document?inside a?collection?called?messages?in our?database, which we have access to via the?db?import. If the?collection?doesn't exist, it will create it for us.

It also creates?key-value pairs, storing our?message?in?text,?displayName?in?name, storing the?time?the message was saved in our database in?createdAt, and then the user’s?uid.

These key-value pairs are what make up the data for our document. After this is done, it then resets the message state to an empty string.

How to Retrieve Messages from Our Database

After sending the user's message, we need to display it on the screen to the user. Going into our?ChatBox?component, we import the following:

import { useEffect, useRef, useState } from "react";
import {
  query,
  collection,
  orderBy,
  onSnapshot,
  limit,
} from "firebase/firestore";
import { db } from "../firebase";        

We create a?useEffect?hook that will run anytime changes are made in the chatroom, like sending or deleting a message.

useEffect(() => {
  const q = query(
    collection(db, "messages"),
    orderBy("createdAt"),
    limit(50)
  );
  const unsubscribe = onSnapshot(q, (QuerySnapshot) => {
    let messages = [];
    QuerySnapshot.forEach((doc) => {
      messages.push({ ...doc.data(), id: doc.id });
    });
    setMessages(messages);
  });
  return () => unsubscribe;
}, []);        

In this?useEffect?hook, we have a const?q, a Firebase query that queries our database looking for a?message?collection. It then?orders?the documents in the collection based on the?createdAt?key, and returns a maximum of?50?documents (messages saved).

The?unsubscribe?const represents the?onSnapshot?function which listens to changes in the document. It has an empty array called?messages.

The?forEach?loop loops through all the?documents?from the?collection?and saves the data in the new array. It then sets the initial messages array to the new messages array.

We also use a?map function?on our messages array to render each message/document data in our?Message?component.

{messages?.map((message) => (
  <Message key={message.id} message={message} />
))}        

The final code looks like this:

import React, { useEffect, useState } from "react";
import {
  query,
  collection,
  orderBy,
  onSnapshot,
  limit,
} from "firebase/firestore";
import { db } from "../firebase";
import Message from "./Message";
import SendMessage from "./SendMessage";

const ChatBox = () => {
  const [messages, setMessages] = useState([]);
  
  useEffect(() => {
    const q = query(
      collection(db, "messages"),
      orderBy("createdAt"),
      limit(50)
    );
    const unsubscribe = onSnapshot(q, (QuerySnapshot) => {
      let messages = [];
      QuerySnapshot.forEach((doc) => {
        messages.push({ ...doc.data(), id: doc.id });
      });
      setMessages(messages);
    });
    return () => unsubscribe;
  }, []);

  return (
    <main className="chat-box">
      <div className="messages-wrapper">
        {messages?.map((message) => (
          <Message key={message.id} message={message} />
        ))}
      </div>
      <SendMessage />
    </main>
  );
};
export default ChatBox;        

Going into our?Message?component, let's render the data passed into it in our browser.

import React from "react";
import { auth } from "../firebase";
import { useAuthState } from "react-firebase-hooks/auth";
const Message = ({ message }) => {
  const [user] = useAuthState(auth);

  return (
    <div
      className={`chat-bubble ${message.uid === user.uid ? "right" : ""}`}>
      <img
        className="chat-bubble__left"
        src={message.avatar}
        alt="user avatar"
      />
      <div className="chat-bubble__right">
        <p className="user-name">{message.name}</p>
        <p className="user-message">{message.text}</p>
      </div>
    </div>
  );
};
export default Message;        

We imported?auth?and?useAuthState and stored the user details in?user. We deconstructed the messages prop and passed the avatar into the img src attribute. We also replaced the dummy name and message with the one gotten from the message data.

We also conditioned a CSS style to take effect based on the uid of the message's author. So if the message’s author uid is the same as the uid of the person logged in, then the CSS styles stored in the selector?right?should be added to the div. Otherwise, no new style should be added.

Currently, all messages are positioned to the left, so if the logged user is the message’s author, their message should be positioned to the right. Let's view these changes in our browser:

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Updated app demo

The message is sent and stored in our database. Then all the messages are retrieved, and the chatroom is updated in real-time with the new messages.

The name and avatar of the user are also present on the message card. But we can also see that the chat doesn't scroll to the bottom when a new message enters. Let's fix that.

How to Add Scroll to the Bottom

Going into our?ChatBox.js, we import the?useRef?hook and create a const called?scroll:

import React, { useEffect, useRef, useState } from "react";
...
const scroll = useRef();        

We then create a?span?element with a?ref?attribute whose value is?scroll, and also pass the?scroll?into our?Messages?component:

<main className="chat-box">
   ...
   {/* when a new message enters the chat, the screen scrolls dowwn to the scroll div */}
   <span ref={scroll}></span>
   <SendMessage scroll={scroll} />
</main>        

We then go into the?Messages?component, access the scroll const, and add?scroll.current.scrollIntoView({ behavior: "smooth" })?to the bottom of our?sendMessage?function.

This code tells the browser to let the scroll span be in view in the browser after sending a message. That is why the span tag was placed at the bottom of all the messages.

const SendMessage = ({ scroll }) => {

  const sendMessage = async (event) => {
   ...
    setMessage("");
    scroll.current.scrollIntoView({ behavior: "smooth" });
  };
  ...
};        

Going back to the browser, we should see the chat scroll to the bottom when the user sends in a new message.

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Demo shows chat scrolling to the bottom with a new message

Wrapping Up

And that's it on building a real-time chat app. Congrats!

In this tutorial, we learned how to use Firebase and React to build a real-time chat app. We also authenticated the users using Firebase Authentication’s Google sign-in method and stored the chat room messages in a database using Cloud Firestore. We also learned how to use some of Firebase’s services and libraries.

If you enjoyed this article, consider sharing it to help other developers. You could also visit?my Linkedin Profile?to read more articles from me and you can connect with me on??LinkedIn.

Till next time guys, byeeeeee!

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