Implementing a Real-Time Chat Feature in React Native

Muhammad Aamir Yameen

April 21, 2025

165 mint

Table of Content

Prerequisites Step 1: Setting Up the React Native Project Step 2: Configuring Firebase Step 3: Setting Up Navigation Step 5: Building the Chat Screen Step 6: Firestore Security Rules Step 7: Running the App Additional Considerations Conclusion

React Native

Real-time chat is a critical feature for modern mobile applications, enabling seamless communication between users. This article explores how to build a real-time chat feature in a React Native application using Firebase as the backend for real-time messaging.

Prerequisites

Basic knowledge of React Native and JavaScript.
Node.js and npm installed.
A Firebase account for backend services.
React Native CLI or Expo CLI set up.

Step 1: Setting Up the React Native Project

First, create a new React Native project if you don’t already have one:

npx react-native init ChatApp

cd ChatApp
Install the necessary dependencies for Firebase and navigation:

npm install @react-navigation/native @react-navigation/stack react-native-gifted-chat firebase

npx pod-install ios

Step 2: Configuring Firebase

Go to the Firebase Console and create a new project.
Add an app to your Firebase project (select iOS or Android) and follow the setup instructions to download the configuration file (GoogleService-Info.plist for iOS or google-services.json for Android).
Place the configuration file in the appropriate directory of your React Native project.
Enable Firestore in the Firebase Console under "Build > Firestore Database" and create a new database.

In your project, initialize Firebase by creating a firebaseConfig.js file:

import firebase from 'firebase/app';

import 'firebase/firestore';

import 'firebase/auth';

const firebaseConfig = {

apiKey: 'YOUR_API_KEY',

authDomain: 'YOUR_AUTH_DOMAIN',

projectId: 'YOUR_PROJECT_ID',

storageBucket: 'YOUR_STORAGE_BUCKET',

messagingSenderId: 'YOUR_MESSAGING_SENDER_ID',

appId: 'YOUR_APP_ID',

};

if (!firebase.apps.length) {

firebase.initializeApp(firebaseConfig);

}

export const db = firebase.firestore();

export const auth = firebase.auth();

export default firebase;

Replace the placeholders with your Firebase project’s configuration details.

Step 3: Setting Up Navigation

Set up navigation to switch between a login screen and the chat screen. Create a navigation folder and add a AppNavigator.js file:

import React from 'react';

import { NavigationContainer } from '@react-navigation/native';

import { createStackNavigator } from '@react-navigation/stack';

import LoginScreen from '../screens/LoginScreen';

import ChatScreen from '../screens/ChatScreen';

const Stack = createStackNavigator();

const AppNavigator = () => (

<Stack.Navigator initialRouteName="Login">

<Stack.Screen name="Login" component={LoginScreen} />

<Stack.Screen name="Chat" component={ChatScreen} />

</Stack.Navigator>

</NavigationContainer>

);

export default AppNavigator;

Update App.js to use the navigator:

import React from 'react';

import AppNavigator from './navigation/AppNavigator';

export default function App() {

return <AppNavigator />;

}

Step 4: Creating the Login Screen

Create a screens folder and add LoginScreen.js to handle user authentication:

import React, { useState } from 'react';

import { View, TextInput, Button, StyleSheet } from 'react-native';

import { auth } from '../firebaseConfig';

const LoginScreen = ({ navigation }) => {

const [email, setEmail] = useState('');

const [password, setPassword] = useState('');

const handleLogin = async () => {

try {

await auth.signInWithEmailAndPassword(email, password);

navigation.navigate('Chat');

} catch (error) {

console.error(error);

}

};

const handleSignUp = async () => {

try {

await auth.createUserWithEmailAndPassword(email, password);

navigation.navigate('Chat');

} catch (error) {

console.error(error);

}

};

return (

<TextInput

style={styles.input}

placeholder="Email"

value={email}

onChangeText={setEmail}

<TextInput

style={styles.input}

placeholder="Password"

value={password}

onChangeText={setPassword}

secureTextEntry

</View>

);

};

const styles = StyleSheet.create({

container: { flex: 1, justifyContent: 'center', padding: 16 },

input: { borderWidth: 1, padding: 8, marginBottom: 16 },

});

export default LoginScreen;

Step 5: Building the Chat Screen

Use the react-native-gifted-chat library to create a polished chat UI. Create ChatScreen.js in the screens folder:

import React, { useState, useEffect, useCallback } from 'react';

import { GiftedChat } from 'react-native-gifted-chat';

import { db, auth } from '../firebaseConfig';

const ChatScreen = () => {

const [messages, setMessages] = useState([]);

useEffect(() => {

const unsubscribe = db

.collection('messages')

.orderBy('createdAt', 'desc')

.onSnapshot((snapshot) => {

const messageList = snapshot.docs.map((doc) => ({

_id: doc.id,

text: doc.data().text,

createdAt: doc.data().createdAt.toDate(),

user: doc.data().user,

}));

setMessages(messageList);

});

return () => unsubscribe();

}, []);

const onSend = useCallback((newMessages = []) => {

const message = newMessages[0];

db.collection('messages').add({

text: message.text,

createdAt: new Date(),

user: {

_id: auth.currentUser.uid,

name: auth.currentUser.email,

});

}, []);

return (

<GiftedChat

messages={messages}

onSend={(newMessages) => onSend(newMessages)}

user={{

_id: auth.currentUser.uid,

name: auth.currentUser.email,

}}

);

};

export default ChatScreen;

Step 6: Firestore Security Rules

To ensure only authenticated users can read and write messages, update your Firestore security rules in the Firebase Console:

rules_version = '2';

service cloud.firestore {

match /databases/{database}/documents {

match /messages/{messageId} {

allow read, write: if request.auth != null;

}

Step 7: Running the App

Start the Metro bundler and run the app:

npx react-native run-android

# or

npx react-native run-ios

Additional Considerations

Performance: For large chat applications, consider paginating messages to reduce load times.
Security: Ensure all sensitive data is encrypted and validate user inputs to prevent injection attacks.
UI Customization: Customize the GiftedChat component’s appearance using its props to match your app’s design.
Push Notifications: Integrate Firebase Cloud Messaging (FCM) to notify users of new messages when the app is in the background.

Conclusion

By leveraging Firebase Firestore and react-native-gifted-chat, you can quickly implement a robust real-time chat feature in your React Native application. This setup provides a scalable foundation that you can extend with additional features like media sharing, typing indicators, or group chats.