reconnecting-simple-websocket

State machine for reconnecting simple-websockets. Subclass of reconnecting-socket.

npm install reconnecting-simple-websocket

Usage

const RSWS = require('reconnecting-simple-websocket')

const rsws = new RSWS('ws://localhost:8085', {
  onopen (socket, firstOpen) {
    // What gets called wheny you have a live socket
    console.log('onopen')
    this.pinger = setInterval(() => socket.write('ping'), 1000)
    socket.on('data', buf => console.log(buf.toString('utf8')))
  },

  onclose (socket) {
    // what to do when the socket is closed
    console.log('onclose')
    clearInterval(this.pinger)
  },

  onfail (err) {
    // handle the final error that caused the fail
    console.log('onfail')
    console.error(err)
  }
})

rsws.on('state', (st) => console.log(`state: ${st}`))
rsws.on('info', (st) => console.log(`info: ${st}`))
rsws.on('error', (err) => console.error(`error: ${err}`))

rsws.start() // start it

RSWS can also be subclassed:

const RSWS = require('reconnecting-simple-websocket')

class MySWS extends RSWS {
  constructor (opts) {
    super(opts)

    this.someHandler = this.someHandler.bind(this)
  }

  someHandler (buf) {
    // whatever
  }

  onopen (socket, firstOpen) {
    this.pinger = setInterval(() => socket.write('ping'), 1000)
    socket.on('data', this.someHandler)
  }

  onclose (socket) {
    socket.removeListener('data', this.someHandler)
    clearInterval(this.pinger)
  }

  onfail (err) {
    console.error(err)
  }
}

module.exports = MySWS

API

const RSWS = require('reconnecting-simple-websocket')

Import the RSWS class.

rsws = new ReconnectingSocket(opts)

Create a new reconnecting simple websocket instance. The opts object can receive the user implemented methods listed below as well as the following optional options:

{
  backoff: {
    strategy: 'fibonacci', // the backoff strategey to use
    failAfter: null, // the number of consecutive times to attemt a reconnect before failing
    ...backoffOptions // all the options from the backoff module
  }
}

See full set of backoff options here: MathieuTurcotte/node-backoff

rsws Events

An instance of rsws inherets the same events as reconnecting-socket.

• state: The state emmits the following state strings:
  • stopped
  • opening
  • opened
  • closing
  • closed
  • reopening
  • fail
• info: Messages that can be used for debugging.
• error: Errors emitted by the socket or internally. For an error handling path, see reconnectingSocket.onfail(err).

rsws.start()

Start the reconnecting simple websocket.

rsws.stop()

Stop the reconnecting simple websocket.

User Implemented Methods

rsws.onopen(socket, firstOpen)

This method is called whenever a new socket is created and the this.open() method has been called, so the socket should be live and ready for data. It receives the socket as well as firstOpen boolean which indicates if this is the first successful connection since calling reconnectingSocket.start(). Interact with the socket in this function body.

rsws.onclose(socket)

This method is called when the this.close() method is called. Use this to clean up any event listeners or intervals used on the socket.

rsws.onfail(err)

This method is called when the reconnectignSocket fails to connect after failAfter concecutive attempts. It receives the last error emitted by the various moving parts.

See also

• reconnecting-socket
• simple-websocket
• ws

License

MIT