longwebsocket

longwebsocket v1.0.1-beta

Reconnecting wrapper around native WebSocket

While browsers' native WebSocket object simply stops functioning when the connection is lost, this module takes care of reviving the connection and keeping handlers active. It also makes sure to randomize progressively longer delays up to 30 seconds between retries to avoid flooding a server as it comes back online.

Installation & Usage

Client-side, stand-alone using Bower

bower install longwebsocket --save

You can then integrate bowe_components/longwebsocket/longwebsocket.min.js to your build as needed. (The non-minified version is a CommonJS module, not suitable for direct browser use.) This was generated using browserify --standalone and is thus safe as-is or with various module systems. Stand-alone example:

<script src="longwebsocket.min.js"></script>
...
<script type="text/javascript"><!--
  var ws = new LongWebSocket();
  ...
// --></script> 

Node.JS and client-side (CommonJS)

npm install longwebsocket --save

In Node.JS or if you're using Browserify to bundle CommonJS modules together for client-side use, you can choose whichever name you'd like, although in this document we'll assume LongWebSocket. For example:

var LongWebSocket = require('longwebsocket');
var ws = new LongWebSocket();
...

Usage example

var ws = new LongWebSocket({
  onmessage: function(msg) {
    console.log('Received: ' + msg);
    ws.send(msg);  // Simple echo
  },
  onopen: function() {
    console.log("There we go, we're online now, we can send!");
  },
  onclose: function() {
    console.log("Offline! Not for long, I'm sure...");
  }
});

API

ws = new LongWebSocket([options])

If supplied, the options is an object which may include any combination of:

url: If omitted, a WebSocket will be attempted at the current location's host and port. HTTPS will also correctly yield a WSS socket.

protocols: Passed directly to WebSocket.

onmessage: Callback for you to receive messages as they arrive. It will be given a single argument containing the message itself.

onopen: Called each time the WebSocket becomes available for sending, if specified.

onclose: Called each time the WebSocket gets closed (including by you).

All arguments are optional, but only a specific set of combinations are allowed: a single argument must be onmsg. If there are more than one argument, there may be up to 2 strings left of onmsg which will be processed as either (protocols) or (url, protocols) according to count. To the right of onmsg the immediate next is considered onopen, then onclose.

ws.send(msg)

Send message msg to the other end. Any error would bubble up from the underlying WebSocket.

ws.close([code[, reason]])

Close the WebSocket and do not attempt to reconnect it. Arguments are passed directly to WebSocket.

ws.open()

Re-open a closed LongWebSocket. Previously defined options are retained.

MIT License

Copyright (c) 2016 Stephane Lavergne https://github.com/vphantom

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.