bifrost-wss

bifrost-wss

WebSocket Server & Client library for simple authorized publisher/subscriber communication with rooms/topics.
Also provides a simple request/response pattern (via command).

Provides full control over handlers and instances, with additional helpers for easy integration with WebSocket Server (WSS).

Installation

npm i bifrost-wss

Usage

Server side

import {WSSManager} from 'bifrost-wss'
 const server = new WSSManager( {
    port: 8095,
    host: "localhost",
});
server.createRoom('room-1')
server.createRoom('room-2')

server.addHandler('authorize', function open(peer, accessToken) {
    if(accessToken === process.env.ACCESS_TOKEN) {
        // Deal with Auth for instance, and modify the peer object
        peer.isAuth = true;
    }
})

// Allow a peer to send a command "increment" and get a response
server.addHandler('increment', function increment(peer, message) {
    if(message.requestId){
        peer.send({value: i++, requestId: message.requestId})
    }
});

await server.start()
setInterval(()=>{
    server.logger.level = 'trace';
    server.broadcastRoom('room-1', {type: 'hello', payload: 'room1'})
    server.broadcastRoom('room-2', {type: 'hello', payload: 'room2'})
    server.broadcastAll({type: 'hello', payload: 'all'})
},1000)

Client side

import {WSClient} from 'bifrost-wss'

const client = new WSClient({
    port: 8095,
    host: "localhost",
    headers: {
        access_token: process.env.ACCESS_TOKEN,
    }
});

client.addHandler('open', () => {
    client.authorize();
    setTimeout(() => client.subscribe('room-1'), 10);
    setTimeout(() => client.subscribe('room-2'), 5000);
});

// global handler for all messages, they are in JSON already
client.addHandler('message', (message) => {
    console.log(message);
});

// Will be called only for messages from room-1
client.addHandler('room-1', function message(message) {
    console.log('room-1 handler', message)
});

await client.open();

// Will send a command to the server and wait for a response
const req = client.send({
    cmd: 'increment',
})
const res = await req;
console.log('increment response', res)

Commands

When .send() is called with a cmd property, a requestId will be generated, and a listener associated with the requestId will be created. The response will be awaited and the listener removed.

{
    cmd: 'subscribe',
    room: 'time-beacon'
}

Events

{
    topic: 'time-beacon',
    payload: {time: 1234567890}
}

Features

• Room/Topic-Based Communication: Enables communication in specific channels.
• WebSocket Server and Client: Provides both server and client components.
• Reconnection: Reconnects automatically if the connection drops.
• Authorization: Pre-build authorization logic
• On-the-fly room management: Allows for the creation and removal of rooms on the fly.
• Extensible Event Handlers: Supports adding custom handlers for WebSocket events.
• Request/Response Pattern: Supports a simple request/response pattern.

API Reference

WSSManager (Server Component)

new WSSManager(options)

• Description: Initializes a new WebSocket server.
• Parameters:
  • options: Object containing configuration options.
    • port: (Number) The port number for the server.
    • host: (String) The host address for the server.
    • logger: (Object) Custom logger object.

start()

• Description: Starts the WebSocket server.

stop()

• Description: Stops the WebSocket server.

createRoom(roomName, force = false)

• Description: Creates a new room.
• Parameters:
  • roomName: (String) Name of the room to create.
  • force: (Boolean) Whether to force the creation of the room if it already exists.

removeRoom(roomName)

• Description: Removes an existing room.
• Parameters:
  • roomName: (String) Name of the room to remove.

broadcastRoom(roomName, message, sender = null, broadcastToSelf = false)

• Description: Broadcasts a message to all clients in a specified room.
• Parameters:
  • roomName: (String) Name of the room.
  • message: (Object) Message object to broadcast.
  • sender: (Object) Sender peer object. (Optional)
  • broadcastToSelf: (Boolean) Whether to broadcast to the sender. (Optional)

broadcastAll(message)

• Description: Broadcasts a message to all connected clients.
• Parameters:
  • message: (Object) Message object to broadcast.

addHandler(type, handler)

• Description: Adds a handler for a specific message type.
• Parameters:
  • type: (String) Type of message.
  • handler: (Function) Handler function.

WSClient (Client Component)

new WSClient(options)

• Description: Initializes a new WebSocket client.
• Parameters:
  • options: Object containing configuration options.
    • port: (Number) The port number of the server.
    • host: (String) The host address of the server.
    • headers: (Object) Headers for WebSocket connection.
    • isSecure: (Boolean) When true, use wss - defaults to false.

open()

• Description: Opens the WebSocket connection.

close()

• Description: Closes the WebSocket connection.

subscribe(room)

• Description: Subscribes to a specific room.
• Parameters:
  • room: (String) Name of the room to subscribe to.

authorize(accessToken)

• Description: Authorizes the client using an access token.
• Parameters:
  • accessToken: (String) Access token for authorization.

send(message)

• Description: Sends a message through the WebSocket.
• Parameters:
  • message: (Object/String) Message object or string to send.

addHandler(name, handler)

• Description: Adds a handler for specific client events.
• Parameters:
  • name: (String) Name of the event.
  • handler: (Function) Handler function.