@rxtk/socketio

🚰 Hooks for RxJS Observables to interface with Socket.io (v4) servers

npm i @rxtk/socketio

yarn add @rxtk/socketio

Compatability

Platform	Support
node.js (>10.0)	✅
Browsers	✅
React Native	✅
Electron	✅

API

conduit()

Opens a two-way channel of communication with the server. Items sent into the operator will be sent to the server. By default, the output stream is the messages sent back from the server.

import {from} from 'rxjs';
import {conduit} from '@rxtk/socketio';

const messageIn$ = from([
  {topic: 'message', body: 'yarrr'},
  {topic: 'message', body: 'arrr matey'},
  {topic: 'message', body: 'Vitamin C? Never heard of it.'},
  {topic: 'message', body: 'Why is all the rum gone?'},
]);

const socketConfig = {
  url: 'http://localhost:9080/ws', // socket.io server
  topics: ['message'], // topics to subscribe to. (Defaults to ['message']).
  // the socket options get passed directly to the Socket.io instance, allowing
  // any customization that the socket.io client supports.
  socketOptions: {
    transports: ['websocket'],
    auth: {token: 'secretjwttoken'},
  },
}; 
// the conduit operator sends messages from messageIn$ and emits messages 
// from the server
const messageBack$ = messageIn$.pipe(conduit({...socketConfig}));
messageBack$.subscribe(console.log);
messageBack$.error$.subscribe(console.error); // optional: handle errors
// {topic: 'message', body: 'Welcome Matey.'}
// {topic: 'message', body: 'Yo ho. Yo ho. I am a message from the server.'}

You can also send binary data:

import {from} from 'rxjs';
import {conduit} from '@rxtk/socketio';

const messageIn$ = from([
  {topic: 'next-audio-chunk', index: 0, binary: Buffer.from('foobar', 'base64')},
  {topic: 'next-audio-chunk', index: 1, binary: Buffer.from('foobar', 'base64')},
]);
const socketConfig = {
  url: 'http://localhost:9080/ws',
  topics: ['message', 'audio-received'],
};
messageIn$.pipe(conduit({...socketConfig}));
// {topic: 'audio-received', index: 0}
// {topic: 'audio-received', index: 1}

Advanced configuration

The library also supports some advanced features commonly needed in real applications:

• sending binary
• verifying receipt of messages before sending the next
• customizing the socket.io client
• adding serializers/deserializers
• handling disconnections

See the the code (src/operators/conduit) for advanced configuration options. This is a pretty lightweight wrapper and the code should be pretty easy to read and understand.