WebSocket wrapper for Plumber.js https://github.com/ismasan/plumber.js

websocket_pipe.js

/**
 * WebSocket wrapper for Plumber.js
 *
 * https://github.com/ismasan/plumber.js
 *
 * Reconnect on close with 5 seconds delay
 *
 * Assumes WebSocket messages are JSON strings
 * 
 * Usage:
 * 
 *     // Instantiate
 *     var socket = new SocketRepository('ws://some.server.com')
 * 
 *     // Forward incoming messages to other pipes in your app
 *     socket.pipe(someOtherPlumberPipe)
 *     
 *     // Send data down the socket
 *     socket.add(someStruct)
 */
var SocketRepository = (function () {
  
  var reconnect_delay = 5000;
  
  /* Private stuff
  ------------------------------------*/
  function log() {
    console.log('socket:', arguments)
  }
  
  function logFor(evtName) {
    return function () {
      console.log('socket:', evtName, arguments)
    }
  }
  
  function onclose () {
    log('closed. Reconnect in ', reconnect_delay)
    setTimeout($.proxy(this.__connect, this), reconnect_delay)
  }
  
  function dispatch (evt) {
    var data = JSON.parse(evt.data)
    var struct = new Plumber.Struct(data)
    this.add(struct)
  }
  
  /* Socket repository constructor
  ---------------------------------------------------*/
  var SocketRepository = Plumber.Pipe.extend({
    
    initialize: function (host) {
      this.host = host;
      this.__connect()
    },
    /**
     * Sends a serialized struct down the websocket
     *
     * @param {Struct} struct The Struct instance being forwarded.
     * @param {$.Deferred} promise to be fulfilled on success (or immediatly for fire-and-forget behaviour)
     */
    _add: function (struct, promise) {
      // Insert your custom serialization here, or queue and wait for socket to connect, etc.
      this.ws.send(JSON.stringify(struct.attributes))
      // Do not resolve if you don't want this pipe to forward to other pipes.
      promise.resolve(struct)
    },
    
    __connect: function () {
      log('connecting')
      this.ws = new WebSocket(this.host)
      this.ws.onopen = logFor('open')
      this.ws.onclose = $.proxy(onclose, this)
      this.ws.onmessage = $.proxy(dispatch, this)
    }
  })

  return SocketRepository
})()