ReWebSocket: WebSocket with automatic reconnection

ReWebSocket is 99% API-compatible with WebSocket:

var WebSocket = require('ws');
var ReWebSocket = require('rewebsocket')(WebSocket);

var ws = new ReWebSocket("ws://127.0.0.1:3000");
ws.open();  // the only big difference: need to call open explicitly!

ws.onmessage = function(event) {
  console.log("Received %j", event.data);
};
ws.onopen = function(event) {
  console.log("Connected");
};
ws.onclose = function(event) {
  if (event.previousReadyState == WebSocket.OPEN)
    console.log("Disconnected");
  else
    console.log("Connection failed.");
};
ws.onerror = function(event) {
  // in most cases, you only want to handle this event for logging purposes
  // console.log("Error: %s", event.message);
};
ws.onconnecting = function(event) {
  console.log("Connecting...");
};

Installation

npm install rewebsocket

Also works as a client-side module via Browserify.

API differences from WebSocket

Method differences:

• You need to call open explicitly to start connection.
• You can call open and close multiple times; after you call open, ReWebSocket will try to keep the connection open until you call close.
• Additional reconnect method closes and reopens the connection.

Event differences:

• In onclose, readyState will be WebSocket.CONNECTING if a reconnection attempt is pending, and WebSocket.CLOSED after an explicit close call.
• In onclose, additional previousReadyState property is provided. You can use it to distinguish failed connection attempts from aborted connections, as demonstrated by the example above.
• Additional onconnecting event is fired before each connection attempt.

Properties:

• timeoutInterval — connectiont timeout in milliseconds, defaults to 10000.
• reconnectIntervals — array of delays between reconnection attempts, in milliseconds; defaults to [10, 100, 500, 1000, 2000, 3000, 5000, 8000, 13000, 21000, 34000, 55000, 60000]; use this to specify your preferred back-off scheme; after a successful connection, the first value is used again; the last value is the maximum interval.

Running the example

node example/example.js

For additional logging, try:

DEBUG=rewebsocket node example/example.js

License

© 2012 Andrey Tarantsov andrey@tarantsov.com.

Provided under the MIT license.