Build a Multi-User Chat With JavaScript
In this guide, you will build a multi-user chat application with Directus’ WebSockets interface that authenticate users with an existing account, show historical messages stored in Directus, allow users to send new messages, and immediately update all connected chats.
Before You Start
Set Up Your Directus Project
You will need a Directus project. If you don’t already have one, the easiest way to get started is with our managed Directus Cloud service.
Create a new collection called messages, with date_created and user_created fields enabled in the Optional System Fields pane on collection creation. Create a text field called text.
Create a new Role called Users, and give Create and Read access to the Messages collection, and Read access to the Directus Users system collection. Create a new user with this role. Make note of the password you set.
Create an HTML Boilerplate
Create an index.html file and open it in your code editor:
<!DOCTYPE html>
<html>
<body>
<form id="login">
<label for="email">Email</label>
<input type="email" id="email" />
<label for="password">Password</label>
<input type="password" id="password" />
<input type="submit" />
</form>
<ol></ol>
<form id="new">
<label for="message">Message</label>
<input type="text" id="text" />
<input type="submit" />
</form>
<script></script>
</body>
</html><!DOCTYPE html>
<html>
<body>
<form id="login">
<label for="email">Email</label>
<input type="email" id="email" />
<label for="password">Password</label>
<input type="password" id="password" />
<input type="submit" />
</form>
<ol></ol>
<form id="new">
<label for="message">Message</label>
<input type="text" id="text" />
<input type="submit" />
</form>
<script></script>
</body>
</html>The first form will handle user login and the second will handle new message submissions. The empty <ol> will be populated with messages.
Inside of the <script>, create a url variable being sure to replace your-directus-url with your project’s URL:
const url = 'wss://your-directus-url/websocket';
let connection;const url = 'wss://your-directus-url/websocket';
let connection;The connection variable will later contain a WebSocket instance.
Finally, create event listeners which are triggered on the form submissions:
document.querySelector('#login').addEventListener('submit', function (event) {
event.preventDefault();
});
document.querySelector('#new').addEventListener('submit', function (event) {
event.preventDefault();
});document.querySelector('#login').addEventListener('submit', function (event) {
event.preventDefault();
});
document.querySelector('#new').addEventListener('submit', function (event) {
event.preventDefault();
});Establish WebSocket Connection
Within the #login form submit event handler, extract the email and password values from the form:
const email = event.target.elements.email.value;
const password = event.target.elements.password.value;const email = event.target.elements.email.value;
const password = event.target.elements.password.value;Create a new WebSocket, which will immediately attempt connection:
connection = new WebSocket(url);connection = new WebSocket(url);On connection, you must send an authentication message before the timeout. Add an event handler for the connection's open event:
connection.addEventListener('open', function () {
connection.send(
JSON.stringify({
type: 'auth',
email,
password,
})
);
});connection.addEventListener('open', function () {
connection.send(
JSON.stringify({
type: 'auth',
email,
password,
})
);
});Subscribe To Messages
In a WebSocket connection, all data sent from the server will trigger the connection’s message event. Underneath the open event handler, add the following:
connection.addEventListener('message', function (message) {
receiveMessage(message);
});connection.addEventListener('message', function (message) {
receiveMessage(message);
});At the bottom of your <script>, create the receiveMessage function:
function receiveMessage(message) {
const data = JSON.parse(message.data);
}function receiveMessage(message) {
const data = JSON.parse(message.data);
}As soon as you have successfully authenticated, a message will be sent. When this happens, subscribe to updates on the Messages collection. Add this inside of the receiveMessage function:
if (data.type == 'auth' && data.status == 'ok') {
connection.send(
JSON.stringify({
type: 'subscribe',
collection: 'messages',
query: {
fields: ['*', 'user_created.first_name'],
sort: 'date_created',
},
})
);
}if (data.type == 'auth' && data.status == 'ok') {
connection.send(
JSON.stringify({
type: 'subscribe',
collection: 'messages',
query: {
fields: ['*', 'user_created.first_name'],
sort: 'date_created',
},
})
);
}When a subscription is started, a message will be sent to confirm. Add this inside of the receiveMessage function:
if (data.type == 'subscription' && data.event == 'init') {
console.log('subscription started');
}if (data.type == 'subscription' && data.event == 'init') {
console.log('subscription started');
}Open your index.html file in your browser, enter your user’s email and password, submit, and check the browser console for this console log.
Create New Messages
Within the #new form submit event handler, send a new message to create the item in your Directus collection:
document.querySelector('#new').addEventListener('submit', function (event) {
event.preventDefault();
const text = event.target.elements.text.value;
connection.send(
JSON.stringify({
type: 'items',
collection: 'messages',
action: 'create',
data: { text },
})
);
document.querySelector('#text').value = '';
});document.querySelector('#new').addEventListener('submit', function (event) {
event.preventDefault();
const text = event.target.elements.text.value;
connection.send(
JSON.stringify({
type: 'items',
collection: 'messages',
action: 'create',
data: { text },
})
);
document.querySelector('#text').value = '';
});Refresh your browser, login, and submit a new message. Check the Messages collection in your Directus project and you should see a new item.
Display New Messages
At the bottom of your <script>, create an addMessageToList function:
function addMessageToList(message) {
const li = document.createElement('li');
li.setAttribute('id', message.id);
li.textContent = `${message.user_created.first_name}: ${message.text}`;
document.querySelector('ol').appendChild(li);
}function addMessageToList(message) {
const li = document.createElement('li');
li.setAttribute('id', message.id);
li.textContent = `${message.user_created.first_name}: ${message.text}`;
document.querySelector('ol').appendChild(li);
}In your receiveMessage function, listen for new create events on the Messages collection:
if (data.type == 'subscription' && data.event == 'create') {
addMessageToList(data.data[0]);
}if (data.type == 'subscription' && data.event == 'create') {
addMessageToList(data.data[0]);
}Refresh your browser, login, and submit a new message. The result should be shown on the page. Open a second browser and navigate to your index.html file, login and submit a message there and both pages should immediately update
Display Historical Messages
Replace the console.log() you created when the subscription is initialized:
if (data.type == 'subscription' && data.event == 'init') {
console.log('subscription started');
for (const message of data.data) {
addMessageToList(message);
}
}if (data.type == 'subscription' && data.event == 'init') {
console.log('subscription started');
for (const message of data.data) {
addMessageToList(message);
}
}Refresh your browser, login, and you should see the existing messages shown in your browser.
Next Steps
This guide covers authentication, item creation, and subscription using WebSockets. You may consider:
- Hiding the login form and only showing the new message form once authenticated.
- Handling reconnection logic if the client disconnects or a refresh token is needed.
- Locking down permissions so users can only see user first names.
- Allow for editing and deletion of messages by the author or by an admin.
Full Code Sample
<!DOCTYPE html>
<html>
<body>
<form id="login">
<label for="email">Email</label>
<input type="email" id="email" />
<label for="password">Password</label>
<input type="password" id="password" />
<input type="submit" />
</form>
<ol></ol>
<form id="new">
<label for="message">Message</label>
<input type="text" id="text" />
<input type="submit" />
</form>
<script>
const url = 'wss://your-directus-url/websocket';
let connection;
document.querySelector('#login').addEventListener('submit', function (event) {
event.preventDefault();
const email = event.target.elements.email.value;
const password = event.target.elements.password.value;
connection = new WebSocket(url);
connection.addEventListener('open', function () {
connection.send(
JSON.stringify({
type: 'auth',
email,
password,
})
);
});
connection.addEventListener('message', function (message) {
receiveMessage(message);
});
});
document.querySelector('#new').addEventListener('submit', function (event) {
event.preventDefault();
const text = event.target.elements.text.value;
connection.send(
JSON.stringify({
type: 'items',
collection: 'messages',
action: 'create',
data: { text },
})
);
document.querySelector('#text').value = '';
});
function receiveMessage(message) {
const data = JSON.parse(message.data);
if (data.type == 'auth' && data.status == 'ok') {
connection.send(
JSON.stringify({
type: 'subscribe',
collection: 'messages',
query: {
fields: ['*', 'user_created.first_name'],
sort: 'date_created',
},
})
);
}
if (data.type == 'subscription' && data.event == 'init') {
for (const message of data.data) {
addMessageToList(message);
}
}
if (data.type == 'subscription' && data.event == 'create') {
addMessageToList(data.data[0]);
}
}
function addMessageToList(message) {
const li = document.createElement('li');
li.setAttribute('id', message.id);
li.textContent = `${message.user_created.first_name}: ${message.text}`;
document.querySelector('ol').appendChild(li);
}
</script>
</body>
</html><!DOCTYPE html>
<html>
<body>
<form id="login">
<label for="email">Email</label>
<input type="email" id="email" />
<label for="password">Password</label>
<input type="password" id="password" />
<input type="submit" />
</form>
<ol></ol>
<form id="new">
<label for="message">Message</label>
<input type="text" id="text" />
<input type="submit" />
</form>
<script>
const url = 'wss://your-directus-url/websocket';
let connection;
document.querySelector('#login').addEventListener('submit', function (event) {
event.preventDefault();
const email = event.target.elements.email.value;
const password = event.target.elements.password.value;
connection = new WebSocket(url);
connection.addEventListener('open', function () {
connection.send(
JSON.stringify({
type: 'auth',
email,
password,
})
);
});
connection.addEventListener('message', function (message) {
receiveMessage(message);
});
});
document.querySelector('#new').addEventListener('submit', function (event) {
event.preventDefault();
const text = event.target.elements.text.value;
connection.send(
JSON.stringify({
type: 'items',
collection: 'messages',
action: 'create',
data: { text },
})
);
document.querySelector('#text').value = '';
});
function receiveMessage(message) {
const data = JSON.parse(message.data);
if (data.type == 'auth' && data.status == 'ok') {
connection.send(
JSON.stringify({
type: 'subscribe',
collection: 'messages',
query: {
fields: ['*', 'user_created.first_name'],
sort: 'date_created',
},
})
);
}
if (data.type == 'subscription' && data.event == 'init') {
for (const message of data.data) {
addMessageToList(message);
}
}
if (data.type == 'subscription' && data.event == 'create') {
addMessageToList(data.data[0]);
}
}
function addMessageToList(message) {
const li = document.createElement('li');
li.setAttribute('id', message.id);
li.textContent = `${message.user_created.first_name}: ${message.text}`;
document.querySelector('ol').appendChild(li);
}
</script>
</body>
</html>