mesa-js-client

A simple JavaScript client for connecting to Mesa servers.

Important: mesa-js-client is only recommended for use in non-Node.js environments. Please use the Client implementation in @cryb/mesa if you're attempting to connect to a Mesa server from a Node.js environment

Installation

Module

This module library is available on the NPM registry. To install, run:

npm i mesa-js-client --save

If you're using Yarn, run:

yarn add mesa-js-client

Browser

To install the browser library, copy dist/browser/client.js and refer to it in your .html file like so:

<script src="client.js"></script>

mesa-js-server is also offered via the jsdelivr CDN:

<script src="https://cdn.jsdelivr.net/npm/mesa-js-client@latest/dist/browser/client.js"></script>

Usage

The client API is more or less identical to the Client implementation in @cryb/mesa, with a few caveats:

• mesa-js-client does not use EventEmitter in order to inform the application of events. Instead, we use callbacks in the form of:
  • onConnected: () => void
  • onMessage: (message: Message) => void
  • onDisconnected: (code: number, reason: string) => void
  • onError: (error: Error) => void

The constructor for MesaClient also allows for options to be passed in:

const client = new MesaClient('ws://localhost:4000', { autoConnect: false })

// With autoConnect set to false, client.connect will now need to be called in order for the connected to begin
client.connect()

Authentication

mesa-js-client also supports authentication through the Mesa Authentication API. Once enabled on the server, client-side authentication material can be sent like this:

client.onConnected = async () => {
  const user = await client.authenticate({ token: fetchToken() }, { shouldSync: true })
}

The second parameter in the client.authenticate method is an optional configuration object that can be supplied with information such as shouldSync, which matches the Mesa usage of sending undelivered messages since the last disconnection

Example

Module

import MesaClient from 'mesa-js-client'

const client = new MesaClient('ws://localhost:4000')

client.onConnected = () => {
  console.log('Connected to Mesa server')
}

client.onMessage = ({ opcode, data, type }) => {
  console.log('Recieved', opcode, data, type)

  switch(type) {
    case 'PING':
    client.send(0, {}, 'PONG')
    break
  }
}

client.onDisconnected = (code, reason) => {
  console.log('Disconnected', code, reason)
}

client.onError = error => {
  console.log('Error', error)
}

Browser

<script src="js/mesa-js-client.js"></script>
<script>
  const client = new MesaClient("ws://localhost:4000")

  client.onConnected = function() {
    console.log("Connected to Mesa server")
  }

  client.onMessage = function({ opcode, data, type }) {
    console.log("Recieved", opcode, data, type)

    switch(type) {
      case "PING":
      client.send(0, {}, "PONG")
      break
    }
  }

  client.onDisconnected = function(code, reason) {
    console.log("Disconnected", code, reason)
  }

  client.onError = function(error) {
    console.log("Error", error)
  }

  client.connect()
</script>

Questions / Issues

If you have an issues with mesa-js-client, please either open a GitHub issue or contact a maintainer