Connection Class

Connection is an object returned by the connect method of the Client class, representing a bidirectional connection with the server. This guide will teach you to:

Send and receive messages
Listen for events
Manage connections

Properties

id

Each new connection is assigned a random 20-character identifier.

This identifier is synchronized with the server-side value.

type=note
This ID is regenerated each time a reconnection occurs.

// Client-side
connection.on("connect", () => {
    console.log(connection.id); // Example output: XBtqzsRMPh7MaVvaAAAB
});
connection.on("disconnect", () => {
    console.log(connection.id); // undefined
});

// Server-side
server.on("connect", ({ connection }) => {
    console.log(connection.id); // Example output: XBtqzsRMPh7MaVvaAAAB
});

roomId

The ID of the room to which the connection belongs.

console.log('connection.roomId'); // Example output: "room1"

connected

Indicates whether the connection is currently connected to the server.

connection.on("connect", () => {
    console.log(connection.connected); // true
});
connection.on("disconnect", () => {
    console.log(connection.connected); // false
});

Lifecycle

connection_class-lifecycle

Methods

send

Use the send method to send messages to the server.

connection.send('Hello, server!');
connection.send('Hello, server!', 'document');
connection.send({ userId: 'user1', active: true });
connection.send({ userId: 'user1', active: true }, 'my-presence');

Parameters

data: The data to be sent.
type (optional): The message type, used to identify the purpose or category of the message.

Example

// Send a document update
connection.send({ content: 'New paragraph' }, 'my-document');
// Send an online status
connection.send({ userId: 'user1', active: true }, 'my-presence');
// Receive and distinguish messages
connection.on('message', (data, type) => {
    if (type === 'my-document') {
        console.log('Document update:', data);
    } else if (type === 'my-presence') {
        console.log('Status update:', data);
    }
});

close

Use the close method to close the connection.

connection.close();

on

Add an event listener.

connection.on('connect', () => {
    console.log('Connected to the server');
});
connection.on('message', (data, type) => {
    console.log('Received message:', data, 'Type:', type);
});

once

Add a one-time listener that is automatically removed after being triggered.

connection.once('reconnect', (attempts) => {
    console.log(`Reconnection attempt #${attempts}`);
});

off

Remove an event listener.

const handler = () => console.log('Error occurred');
connection.on('error', handler);
connection.off('error', handler);

Events

Supported Events

Event Name	Description	Parameters
`connect`	Triggered when the connection is established	None
`message`	Triggered when a message is received	`data` (message content), `type` (message type)
`disconnect`	Triggered when the connection is disconnected	`reason` (disconnection reasons will be detailed in the table below)
`error`	Triggered when an error occurs	`error` (error object)
`reconnectAttempts`	Triggered during reconnection attempts	`attempts` (number of attempts)
`reconnect`	Triggered when reconnection is successful	`attempts` (number of retries)
`reconnectFailed`	Triggered when reconnection fails	None

Disconnection Reasons

The following table lists the disconnection reasons of the disconnect event.

Value	Description
`CLIENT_DISCONNECT`	Client actively disconnected
`SERVER_DISCONNECT`	Server actively disconnected
`PING_TIMEOUT`	Client failed to respond to ping in time
`TRANSPORT_CLOSE`	Transport layer connection closed
`TRANSPORT_ERROR`	Transport layer error occurred