Build a Slack Clone with React and Pusher Chatkit
In this tutorial, you’ll learn how to build a chat app with React and Chatkit.
When we're done, we'll have a chat application complete with typing indicators, a "who's online" list, and message history:
If you think this sounds like a lot to tackle in one tutorial, you'd normally be right!
However, because we'll be using Chatkit, we can more or less focus exclusively on the front-end React code while Chatkit does the heavy lifting.
What is Chatkit?
Chatkit is a hosted API that helps you build impressive chat features into your applications with less code. Features like,
- Group chat
- One-to-one chat
- Private chat
- Typing indicators
- "Who's online" presence
- Read receipts
- Photo, video, and audio messages
Using our cross-platform SDKs, all chat data is sent to our hosted API where we manage chat state and broadcast it to your clients:
You'll never have to worry about scale or infrastructure, we take care of it all for you.
Perhaps the best way to learn Chatkit is to start building, so I highly recommend you follow along. Along the way, you'll learn best practices when using Chatkit with React.
Steps
This tutorial has been written so that you can follow along, step by step. There are 12 steps in total.
Here's a quick rundown so you know what to expect:
- Download the React starter template
- Create your own Chatkit instance
- Setup a basic Node server
- Identifying the user
- Render the chat screen
- Connect to your Chatkit instance
- Create a Chatkit room
- Create a basic UI layout
- Subscribe to new messages
- Sending messages
- Add realtime typing indicators
- Add a "Who's online" list
Alright, let's code!
Step 1. Download the React starter template
Rather than start from absolute scratch, this walkthrough is based on a minimal starter template:
As you can see, the starter template doesn't contain any interesting logic - just boilerplate we need to run a React application and a simple Node server.
"Server? No one mentioned a server!"
If you're not too familiar with Node, don't worry
😊 . After the next section, we won't need to touch the server.
To get started, download the starter template then run npm install
:
git clone https://github.com/pusher/build-a-slack-clone-with-react-and-pusher-chatkit chatkit-tutorial
cd chatkit-tutorial
npm install
(Note: To see the completed code, you can view the completed
branch or run git checkout complete
locally.)
(Also note: This tutorial assumes the use of npm
, but the equivalent yarn
commands will work as well.)
Step 2. Create your own Chatkit instance
Now you've downloaded the starter template, let's create a Chatkit instance.
To create your own Chatkit instance, head to the dashboard and hit Create new:
Give your instance any name (I called mine "React Chat Tutorial") then take note of your Instance Locator and Secret Key in the Keys tab. We'll need them both in the next section.
Step 3. Setup a basic Node server
While most interactions will happen on the client, Chatkit also needs a server counterpart to create and manage users securely:
We won't authenticate users in this tutorial, but we'll still need to define a route that, when called, creates a Chatkit user.
Start by installing @pusher/chatkit-server
:
npm install --save @pusher/chatkit-server
Then update ./server.js
:
const express = require('express')
const bodyParser = require('body-parser')
const cors = require('cors')
+const Chatkit = require('@pusher/chatkit-server')
const app = express()
+const chatkit = new Chatkit.default({
+ instanceLocator: 'YOUR INSTANCE LOCATOR',
+ key: 'YOUR KEY',
+})
app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())
app.use(cors())
+app.post('/users', (req, res) => {
+ const { username } = req.body
+ chatkit
+ .createUser({
+ id: username,
+ name: username
+ })
+ .then(() => res.sendStatus(201))
+ .catch(error => {
+ if (error.error === 'services/chatkit/user_already_exists') {
+ res.sendStatus(200)
+ } else {
+ res.status(error.status).json(error)
+ }
+ })
+})
+app.post('/authenticate', (req, res) => {
+ const authData = chatkit.authenticate({ userId: req.query.user_id })
+ res.status(authData.status).send(authData.body)
+})
const PORT = 3001
app.listen(PORT, err => {
if (err) {
console.error(err)
} else {
console.log(`Running on port ${PORT}`)
}
})
Remember to replace "YOUR INSTANCE LOCATOR" and "YOUR KEY" with your own respective values.
There's a lot to unpack here, starting from the top:
- First, we import
Chatkit
from@pusher/chatkit-server
- Then, instantiate our own
chatkit
instance using the Instance Locator and Key we noted in the previous step - In the
/users
route, we take ausername
and create a Chatkit user through ourchatkit
instance - Authentication is the action of proving a user is who she says she is. When someone first connects to Chatkit, a request will be sent to
/authenticate
to authenticate them. The server needs to respond with a token (returned bychatkit.authenticate
) if the request is valid. In our case, we'll - naïvely - assume that everyone is who they say they are, and return a token fromchatkit.authenticate
no matter what.
Boom
Step 4. Identifying the user
When someone loads the app, we want to ask them who they are.
Once they hit Submit, we'll send their username to the server (to the /users
route we just defined) and create a Chatkit user if one doesn't exist.
To collect the user's name, create a component called UsernameForm.js
in in ./src/components/
:
+import React, { Component } from 'react'
+class UsernameForm extends Component {
+ constructor(props) {
+ super(props)
+ this.state = {
+ username: '',
+ }
+ this.onSubmit = this.onSubmit.bind(this)
+ this.onChange = this.onChange.bind(this)
+ }
+ onSubmit(e) {
+ e.preventDefault()
+ this.props.onSubmit(this.state.username)
+ }
+ onChange(e) {
+ this.setState({ username: e.target.value })
+ }
+
+ render() {
+ return (
+ <div>
+ <div>
+ <h2>What is your username?</h2>
+ <form onSubmit={this.onSubmit}>
+ <input
+ type="text"
+ placeholder="Your full name"
+ onChange={this.onChange}
+ />
+ <input type="submit" />
+ </form>
+ </div>
+ </div>
+ )
+ }
+}
+
+ export default UsernameForm
Then update App.js
:
import React, { Component } from 'react'
+import UsernameForm from './components/UsernameForm'
class App extends Component {
+ constructor() {
+ super()
+ this.state = {
+ currentUsername: '',
+ }
+ this.onUsernameSubmitted = this.onUsernameSubmitted.bind(this)
+ }
+ onUsernameSubmitted(username) {
+ fetch('http://localhost:3001/users', {
+ method: 'POST',
+ headers: {
+ 'Content-Type': 'application/json',
+ },
+ body: JSON.stringify({ username }),
+ })
+ .then(response => {
+ this.setState({
+ currentUsername: username
+ })
+ })
+ .catch(error => console.error('error', error))
+ }
render() {
- return <h1>Chatly</h1>
+ return <UsernameForm onSubmit={this.onUsernameSubmitted} />
}
}
export default App
Run the application using npm start
and you'll see that the screen is rendered:
Starting from the top of App.js
:
- First, we import the
UsernameForm
component. It probably looks familiar to you because it uses a common React pattern called controlled components. You can read more about React forms here - In the
render
function we render theUsernameForm
and hook up theonUsernameSubmitted
event handler - When
onUsernameSubmitted
is called, we send a POST request to the/users
route we just defined. If the request is successful, we updatethis.state.currentUsername
so we can reference it later; otherwise, weconsole.error
the error
Step 5. Render the chat screen
At the moment, we render the UsernameForm
and it occupies the entire screen (see the above screenshot).
Once the username has been submitted, we'll want to transition to a different screen - namely, the chat screen.
To do that, we first need to create a ChatScreen.js
component in ./src
:
+import React, { Component } from 'react'
+
+class ChatScreen extends Component {
+ render() {
+ return (
+ <div>
+ <h1>Chat</h1>
+ </div>
+ )
+ }
+}
+
+export default ChatScreen
Then update App.js
:
import React, { Component } from 'react'
import UsernameForm from './components/UsernameForm'
+import ChatScreen from './ChatScreen'
class App extends Component {
constructor() {
super()
this.state = {
currentUsername: '',
+ currentScreen: 'WhatIsYourUsernameScreen'
}
this.onUsernameSubmitted = this.onUsernameSubmitted.bind(this)
}
onUsernameSubmitted(username) {
fetch('http://localhost:3001/users', {
method: 'POST',
headers: {
'Content-Type': 'application/json',
},
body: JSON.stringify({ username }),
})
.then(response => {
this.setState({
currentUsername: username,
+ currentScreen: 'ChatScreen'
})
})
.catch(error => console.error('error', error))
}
render() {
+ if (this.state.currentScreen === 'WhatIsYourUsernameScreen') {
return <UsernameForm onSubmit={this.onUsernameSubmitted} />
+ }
+ if (this.state.currentScreen === 'ChatScreen') {
+ return <ChatScreen currentUsername={this.state.currentUsername} />
+ }
}
}
export default App
Rather than use a router, we conditionally render the screen based on this.state.currentScreen
.
Step 6. Connect to your Chatkit instance
Earlier, we installed @pusher/chatkit-server
. Now we're in client-land, you'll need to install @pusher/chatkit-client
as well:
npm install --save @pusher/chatkit-client
Then update ChatScreen.js
:
import React, { Component } from 'react'
+import Chatkit from '@pusher/chatkit-client'
class ChatScreen extends Component {
+ constructor(props) {
+ super(props)
+ this.state = {
+ currentUser: {}
+ }
+ }
+ componentDidMount () {
+ const chatManager = new Chatkit.ChatManager({
+ instanceLocator: 'YOUR INSTANCE LOCATOR',
+ userId: this.props.currentUsername,
+ tokenProvider: new Chatkit.TokenProvider({
+ url: 'http://localhost:3001/authenticate',
+ }),
+ })
+
+ chatManager
+ .connect()
+ .then(currentUser => {
+ this.setState({ currentUser })
+ })
+ .catch(error => console.error('error', error))
+ }
render() {
return (
<div>
<h1>Chat</h1>
</div>
)
}
}
export default ChatScreen
Remember to replace "YOUR INSTANCE LOCATOR" with yours that you noted earlier.
Again, starting from the top:
- First, we import
Chatkit
- Then, instantiate our Chatkit
ChatManager
with ourinstanceLocator
,userId
(fromthis.props.currentUsername
), and a customTokenProvider
. TheTokenProvider
points to the/authenticate
route we defined earlier - Once
ChatManager
has been initialised, we can callconnect
.connect
happens asynchronously and aPromise
is returned. If you've followed these steps exactly, you will connect. That being said, watch out for anyconsole.error
s in case you missed something
Step 7. Create a Chatkit room
When using Chatkit, all messages are sent to a Chatkit room.
Rooms can be created programmatically (on the server or client using createRoom
), or in the dashboard Inspector.
Creating rooms from the Inspector isn't really a good practice (it's mainly intended for testing) but for the purpose of this walkthrough, we'll do it anyway.
In the dashboard, head to the Console tab, where you'll find the Inspector and create a user with any name. I will call mine "Admin".
Then, create a room called "General":
It is really important to note the unique Room id highlighted above.
Step 8. Create a basic UI layout
This step marks a significant point in the walkthrough.
Now we have our boilerplate in place, we can rapidly start to build out chat features.
Going forward, we'll break down each feature into independent (reusable, if you want!) React components:
We will create each component as we go along, but to make the tutorial a bit easier to follow, let's set out the basic component UI layout now:
import React, { Component } from 'react'
import Chatkit from '@pusher/chatkit-client'
class ChatScreen extends Component {
constructor(props) {
super(props)
this.state = {
currentUser: {}
}
}
componentDidMount () {
const chatManager = new Chatkit.ChatManager({
instanceLocator: 'YOUR INSTANCE LOCATOR',
userId: this.props.currentUsername,
tokenProvider: new Chatkit.TokenProvider({
url: 'http://localhost:3001/authenticate',
}),
})
chatManager
.connect()
.then(currentUser => {
this.setState({ currentUser })
})
.catch(error => console.error('error', error))
}
render() {
- return (
- <div>
- <h1>Chat</h1>
- </div>
- )
+ const styles = {
+ container: {
+ height: '100vh',
+ display: 'flex',
+ flexDirection: 'column',
+ },
+ chatContainer: {
+ display: 'flex',
+ flex: 1,
+ },
+ whosOnlineListContainer: {
+ width: '300px',
+ flex: 'none',
+ padding: 20,
+ backgroundColor: '#2c303b',
+ color: 'white',
+ },
+ chatListContainer: {
+ padding: 20,
+ width: '85%',
+ display: 'flex',
+ flexDirection: 'column',
+ },
+ }
+ return (
+ <div style={styles.container}>
+ <div style={styles.chatContainer}>
+ <aside style={styles.whosOnlineListContainer}>
+ <h2>Who's online PLACEHOLDER</h2>
+ </aside>
+ <section style={styles.chatListContainer}>
+ <h2>Chat PLACEHOLDER</h2>
+ </section>
+ </div>
+ </div>
+ )
}
}
export default ChatScreen
If you run the app now, you'll see the basic layout take place:
Awesome!
Step 9. Subscribe to new messages
I am really excited to show you this!
Now we have a Chatkit
connection, building chat features become as simple as hooking up Chatkit events to UI components. Here, let me show you.
First, create a stateless MessageList.js
component in ./src/components
:
+ import React, { Component } from 'react'
+
+ class MessagesList extends Component {
+ render() {
+ const styles = {
+ container: {
+ overflowY: 'scroll',
+ flex: 1,
+ },
+ ul: {
+ listStyle: 'none',
+ },
+ li: {
+ marginTop: 13,
+ marginBottom: 13,
+ },
+ senderUsername: {
+ fontWeight: 'bold',
+ },
+ message: { fontSize: 15 },
+ }
+ return (
+ <div
+ style={{
+ ...this.props.style,
+ ...styles.container,
+ }}
+ >
+ <ul style={styles.ul}>
+ {this.props.messages.map((message, index) => (
+ <li key={index} style={styles.li}>
+ <div>
+ <span style={styles.senderUsername}>{message.senderId}</span>{' '}
+ </div>
+ <p style={styles.message}>{message.text}</p>
+ </li>
+ ))}
+ </ul>
+ </div>
+ )
+ }
+ }
+
+ export default MessagesList
Then update ChatScreen.js
:
import React, { Component } from 'react'
import Chatkit from '@pusher/chatkit-client'
+import MessageList from './components/MessageList'
class ChatScreen extends Component {
constructor(props) {
super(props)
this.state = {
currentUser: {},
+ currentRoom: {},
+ messages: []
}
}
componentDidMount () {
const chatManager = new Chatkit.ChatManager({
instanceLocator: 'YOUR INSTANCE LOCATOR',
userId: this.props.currentUsername,
tokenProvider: new Chatkit.TokenProvider({
url: 'http://localhost:3001/authenticate',
}),
})
chatManager
.connect()
.then(currentUser => {
this.setState({ currentUser })
+ return currentUser.subscribeToRoom({
+ roomId: "YOUR ROOM ID",
+ messageLimit: 100,
+ hooks: {
+ onMessage: message => {
+ this.setState({
+ messages: [...this.state.messages, message],
+ })
+ },
+ },
+ })
+ })
+ .then(currentRoom => {
+ this.setState({ currentRoom })
+ })
.catch(error => console.error('error', error))
}
render() {
const styles = {
...
}
return (
<div style={styles.container}>
<div style={styles.chatContainer}>
<aside style={styles.whosOnlineListContainer}>
<h2>Who's online PLACEHOLDER</h2>
</aside>
<section style={styles.chatListContainer}>
- <h2>Chat PLACEHOLDER</h2>
+ <MessageList
+ messages={this.state.messages}
+ style={styles.chatList}
+ />
</section>
</div>
</div>
)
}
}
export default ChatScreen
Remember to replace YOUR ROOM ID with your own room ID that you noted earlier.
Let's break it down:
- Once you connect to Chatkit you get a
currentUser
object that represents the current connected user - Chatkit is "user-driven" meaning that most if not all interactions happen on the
currentUser
- In this case, we call
subscribeToRoom
on thecurrentUser
(currentUser.subscribeToRoom
) subscribeToRoom
takes an event handler calledonMessage
that is called in real-time each time a new message arrives- Because we specified the
messageLimit
to be100
,onMessage
is also called retroactively for up to100
most recent messages. In practice, this means if you refresh the page you'll see up to100
of the most recent chat messages - There is a fair amount of code here but once you break it down, all we're doing is taking new messages and updating the React state - the significant chat-related code couldn't be more minimal
Step 10. Sending messages
We're on a roll!
Next, let's allow users to send messages by first creating a SendMessageForm.js
component in ./src/components
:
+ import React, { Component } from 'react'
+
+ class SendMessageForm extends Component {
+ constructor(props) {
+ super(props)
+ this.state = {
+ text: '',
+ }
+ this.onSubmit = this.onSubmit.bind(this)
+ this.onChange = this.onChange.bind(this)
+ }
+
+ onSubmit(e) {
+ e.preventDefault()
+ this.props.onSubmit(this.state.text)
+ this.setState({ text: '' })
+ }
+
+ onChange(e) {
+ this.setState({ text: e.target.value })
+ if (this.props.onChange) {
+ this.props.onChange()
+ }
+ }
+
+ render() {
+ const styles = {
+ container: {
+ padding: 20,
+ borderTop: '1px #4C758F solid',
+ marginBottom: 20,
+ },
+ form: {
+ display: 'flex',
+ },
+ input: {
+ color: 'inherit',
+ background: 'none',
+ outline: 'none',
+ border: 'none',
+ flex: 1,
+ fontSize: 16,
+ },
+ }
+ return (
+ <div style={styles.container}>
+ <div>
+ <form onSubmit={this.onSubmit} style={styles.form}>
+ <input
+ type="text"
+ placeholder="Type a message here then hit ENTER"
+ onChange={this.onChange}
+ value={this.state.text}
+ style={styles.input}
+ />
+ </form>
+ </div>
+ </div>
+ )
+ }
+ }
+
+ export default SendMessageForm
Then - you guessed it - update ChatScreen.js
:
import React, { Component } from 'react'
import Chatkit from '@pusher/chatkit-client'
import MessageList from './components/MessageList'
+ import SendMessageForm from './components/SendMessageForm'
class ChatScreen extends Component {
constructor(props) {
super(props)
this.state = {
currentUser: {},
currentRoom: {},
messages: []
}
+ this.sendMessage = this.sendMessage.bind(this)
}
+ sendMessage(text) {
+ this.state.currentUser.sendMessage({
+ text,
+ roomId: this.state.currentRoom.id,
+ })
+ }
componentDidMount () {
const chatManager = new Chatkit.ChatManager({
instanceLocator: 'YOUR INSTANCE LOCATOR',
userId: this.props.currentUsername,
tokenProvider: new Chatkit.TokenProvider({
url: 'http://localhost:3001/authenticate',
}),
})
chatManager
.connect()
.then(currentUser => {
this.setState({ currentUser })
return currentUser.subscribeToRoom({
roomId: YOUR ROOM ID,
messageLimit: 100,
hooks: {
onMessage: message => {
this.setState({
messages: [...this.state.messages, message],
})
},
},
})
})
.then(currentRoom => {
this.setState({ currentRoom })
})
.catch(error => console.error('error', error))
}
render() {
const styles = {
...
}
return (
<div style={styles.container}>
<div style={styles.chatContainer}>
<aside style={styles.whosOnlineListContainer}>
<h2>Who's online PLACEHOLDER</h2>
</aside>
<section style={styles.chatListContainer}>
<MessageList
messages={this.state.messages}
style={styles.chatList}
/>
+ <SendMessageForm onSubmit={this.sendMessage} />
</section>
</div>
</div>
)
}
}
export default ChatScreen
The SendMessageForm
component is essentially the same as theWhatIsYourUsernameForm
component we defined earlier.
When the SendMessageForm
is submitted, we access this.state.currentUser
and call sendMessage
(remember, most interactions happen on currentUser
)
You can probably see a pattern emerging...
ChatScreen
is a container component that manages our application state and renders the UI using presentational - normally stateless - components. Most of our code involves hooking up Chatkit events and their associated data to React UI components.
Step 11. Add realtime typing indicators
If you've ever attempted to implement your own typing indicators, you'll know it can be tricky. In general, more real-time features means more data and more connections to manage.
With Chatkit, you can add typing indicators with little effort.
Start by creating a TypingIndicator.js
component in ./src/components
:
+import React, { Component } from 'react'
+
+class TypingIndicator extends Component {
+ render() {
+ if (this.props.usersWhoAreTyping.length > 0) {
+ return (
+ <div>
+ {`${this.props.usersWhoAreTyping
+ .slice(0, 2)
+ .join(' and ')} is typing`}
+ </div>
+ )
+ }
+ return <div />
+ }
+}
+
+export default TypingIndicator
Then update ChatScreen.js
:
import React, { Component } from 'react'
import Chatkit from '@pusher/chatkit-client'
import MessageList from './components/MessageList'
import SendMessageForm from './components/SendMessageForm'
+import TypingIndicator from './components/TypingIndicator'
class ChatScreen extends Component {
constructor(props) {
super(props)
this.state = {
currentUser: {},
currentRoom: {},
messages: [],
+ usersWhoAreTyping: [],
}
this.sendMessage = this.sendMessage.bind(this)
+ this.sendTypingEvent = this.sendTypingEvent.bind(this)
}
+ sendTypingEvent() {
+ this.state.currentUser
+ .isTypingIn({ roomId: this.state.currentRoom.id })
+ .catch(error => console.error('error', error))
+ }
sendMessage(text) {
this.state.currentUser.sendMessage({
text,
roomId: this.state.currentRoom.id,
})
}
componentDidMount() {
const chatManager = new Chatkit.ChatManager({
instanceLocator: 'YOUR INSTANCE LOCATOR',
userId: this.props.currentUsername,
tokenProvider: new Chatkit.TokenProvider({
url: 'http://localhost:3001/authenticate',
}),
})
chatManager
.connect()
.then(currentUser => {
this.setState({ currentUser })
return currentUser.subscribeToRoom({
roomId: YOUR ROOM ID,
messageLimit: 100,
hooks: {
onMessage: message => {
this.setState({
messages: [...this.state.messages, message],
})
},
+ onUserStartedTyping: user => {
+ this.setState({
+ usersWhoAreTyping: [...this.state.usersWhoAreTyping, user.name],
+ })
+ },
+ onUserStoppedTyping: user => {
+ this.setState({
+ usersWhoAreTyping: this.state.usersWhoAreTyping.filter(
+ username => username !== user.name
+ ),
+ })
+ },
},
})
})
.then(currentRoom => {
this.setState({ currentRoom })
})
.catch(error => console.error('error', error))
}
render() {
const styles = {
...
}
return (
<div style={styles.container}>>
<div style={styles.chatContainer}>
<aside style={styles.whosOnlineListContainer}>
<h2>Who's online PLACEHOLDER</h2>
</aside>
<section style={styles.chatListContainer}>
<MessageList
messages={this.state.messages}
style={styles.chatList}
/>
+ <TypingIndicator usersWhoAreTyping={this.state.usersWhoAreTyping} />
<SendMessageForm
onSubmit={this.sendMessage}
+ onChange={this.sendTypingEvent}
/>
</section>
</div>
</div>
)
}
}
export default ChatScreen
When using Chatkit, typing indicators boil down to two fundamental actions:
- Calling
currentUser.userIsTyping
when the current user starts typing; then, - listening to
userStartedTyping
anduserStoppedTyping
events
And that is pretty much it.
"But Alex, what about when the user stops typing?"
That is a very good question.
Chatkit is intelligent like that. If the service doesn't receive a userIsTyping
event after a few seconds, it assumes the currentUser
has stopped typing. Therefore, there is no need to manually raise an event when someone stops typing. Pretty slick, right?
Step 12. Add a "Who's online" list
Can you feel the momentum? Almost done now
To finish up the chat app, let's use Chatkit's "who's online" feature to render a list of users and their real-time online status.
Start by creating a WhosOnlineList.js
component in /src/components
:
+import React, { Component } from 'react'
+
+class WhosOnlineList extends Component {
+ renderUsers() {
+ return (
+ <ul>
+ {this.props.users.map((user, index) => {
+ if (user.id === this.props.currentUser.id) {
+ return (
+ <WhosOnlineListItem key={index} presenceState="online">
+ {user.name} (You)
+ </WhosOnlineListItem>
+ )
+ }
+ return (
+ <WhosOnlineListItem key={index} presenceState={user.presence.state}>
+ {user.name}
+ </WhosOnlineListItem>
+ )
+ })}
+ </ul>
+ )
+ }
+
+ render() {
+ if (this.props.users) {
+ return this.renderUsers()
+ } else {
+ return <p>Loading...</p>
+ }
+ }
+}
+
+class WhosOnlineListItem extends Component {
+ render() {
+ const styles = {
+ li: {
+ display: 'flex',
+ alignItems: 'center',
+ marginTop: 5,
+ marginBottom: 5,
+ paddingTop: 2,
+ paddingBottom: 2,
+ },
+ div: {
+ borderRadius: '50%',
+ width: 11,
+ height: 11,
+ marginRight: 10,
+ },
+ }
+ return (
+ <li style={styles.li}>
+ <div
+ style={{
+ ...styles.div,
+ backgroundColor:
+ this.props.presenceState === 'online' ? '#539eff' : '#414756',
+ }}
+ />
+ {this.props.children}
+ </li>
+ )
+ }
+}
+
+export default WhosOnlineList
Then - for the last time ChatScreen.js
:
import React, { Component } from 'react'
import Chatkit from '@pusher/chatkit-client'
import MessageList from './components/MessageList'
import SendMessageForm from './components/SendMessageForm'
import TypingIndicator from './components/TypingIndicator'
+import WhosOnlineList from './components/WhosOnlineList'
class ChatScreen extends Component {
constructor(props) {
super(props)
this.state = {
currentUser: {},
currentRoom: {},
messages: [],
usersWhoAreTyping: [],
}
this.sendMessage = this.sendMessage.bind(this)
this.sendTypingEvent = this.sendTypingEvent.bind(this)
}
sendTypingEvent() {
this.state.currentUser
.isTypingIn(this.state.currentRoom.id)
.catch(error => console.error('error', error))
}
sendMessage(text) {
this.state.currentUser.sendMessage({
text,
roomId: this.state.currentRoom.id,
})
}
comonentDidMount() {
const chatManager = new Chatkit.ChatManager({
instanceLocator: 'YOUR INSTANCE LOCATOR',
userId: this.props.currentUsername,
tokenProvider: new Chatkit.TokenProvider({
url: 'http://localhost:3001/authenticate',
}),
})
chatManager
.connect()
.then(currentUser => {
this.setState({ currentUser })
return currentUser.subscribeToRoom({
roomId: YOUR ROOM ID,
messageLimit: 100,
hooks: {
newMessage: message => {
this.setState({
messages: [...this.state.messages, message],
})
},
userStartedTyping: user => {
this.setState({
usersWhoAreTyping: [...this.state.usersWhoAreTyping, user.name],
})
},
userStoppedTyping: user => {
this.setState({
usersWhoAreTyping: this.state.usersWhoAreTyping.filter(
username => username !== user.name
),
})
},
+ onPresenceChange: () => this.forceUpdate(),
},
})
})
.then(currentRoom => {
this.setState({ currentRoom })
})
.catch(error => console.error('error', error))
}
render() {
const styles = {
...
}
return (
<div style={styles.container}>
<header style={styles.header}>
<h2>Chatly</h2>
</header>
<div style={styles.chatContainer}>
<aside style={styles.whosOnlineListContainer}>
- <h2>Who's online PLACEHOLDER</h2>
+ <WhosOnlineList
+ currentUser={this.state.currentUser}
+ users={this.state.currentRoom.users}
+ />
</aside>
<section style={styles.chatListContainer}>
<MessageList
messages={this.state.messages}
style={styles.chatList}
/>
<TypingIndicator usersWhoAreTyping={this.state.usersWhoAreTyping} />
<SendMessageForm
onSubmit={this.sendMessage}
onChange={this.sendTypingEvent}
/>
</section>
</div>
</div>
)
}
}
export default ChatScreen
Managing the state of your users in React state can be a bit tricky so we manage it for you in currentRoom.users
.
As users connect and disconnect, this property is dynamically updated. In other words, currentRoom.users
should always refelect the current state of your chat app.
Therefore, when users come online or go offline (onPresenceChange
), or new users join (onUserAdded
) all we have to do is call forceUpdate
which tells React to evaluate currentRoom.users
and update the UI.
Again, it really boils down to wiring some simple data and events to React components and that's all, folks!
Conclusion
In this walkthrough, you built a complete chat application with
- group chat;
- a “Who’s online” list; and,
- typing indicators
Because we used Chatkit, we also get some bonus features for free:
- message history (refresh the page and you’ll see up to 100 of the most recent messages);
- reliability in the case that the client temporarily loses connection (Chatkit handles disconnects gracefully); and,
- the ability to scale without needing to worry about infrastructure
We wrote a fair amount of code, but none of it was particularly complicated.
Chatkit has a minimal but powerful API that manages all our chat data for us. All we had to do is take that data and render it for the user.
Want to keep building? Why not add rich media support and read receipts? Chatkit supports both:
You may also be interested in checking out our powerful Chatkit Slack demo (250+ stars
What will you build with Chatkit? We'd love to see! Your feedback guides us in improving Chatkit. Let us know what helps you reach your goals, what’s getting in your way, or what’s missing.