Socket.IO Signaler Client

This package is intended to be used as the client component of the Socket.IO Signaler package. It was written in order to interface with a websockets based signaling server and wrap the WebRTC negotiation and GetUserMedia process, offering up a sensible event API.

An important difference between this package and similar WebRTC solutions is that it's built on an exposed Socket.IO socket. This allows you to use the same connection for both chat and webcams in instances where you would like to host your own signaling server.

I will mention that this package was written as an exploration into WebRTC by me. I make no promises as to lifespan or maintenance. I welcome any comments or critiques of the coding style.

For robust, actively-maintained WebRTC helper libraries, I recommend peer.js, rtc.io, and TemaSys SkyLink.

The Signaler Client is only compatible with recent versions of browsers that have implemented WebRTC - Chrome, Firefox, and Opera at time of writing.

Getting Started

The Socket.IO Signaler Client is compatible with vanilla JavaScript and Bower as well as AMD-style (RequireJS) and CommonJS-style (Browserify) module systems.

It is dependent on the Socket.IO client library and the excellent EventEmitter prototype. Both are packaged with the CommonJS include style and are loaded from CDN in the AMD-style include.

You can grab the minified file from the dist folder, or install the whole package with Bower or NPM. You should only use the packaged file if you are using Browserify or another CommonJS module loader:

Installation

//Install package with Bower
bower install --save socket-signaler-client

//Install package with NPM
npm install --save socket-signaler-client

Pure JavaScript

//Include dependencies
<script src="https://cdn.socket.io/socket.io-1.3.3.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/EventEmitter/4.2.11/EventEmitter.min.js"></script>

//Include client
<script src="libs/signaler-client.min.js"></script>

CommonJS (Browserify)

//Include constructor
//Dependencies are packaged
var PeerConnectionClient = require('socket-signaler-client');

AMD (RequireJS)

//Add path to module to your Require config
//Dependencies are loaded from CDN
require.config({
  ...
  paths: {
    ...
    PeerConnectionClient: 'libs/signaler-client',
  },
});

//Pass module into any modules where it is used
require(['PeerConnectionClient'], function (PeerConnectionClient) {
  //Constructor available here
}

Intitialization

var pc = new PeerConnectionClient(options);
//Can use pc to bind to connection lifecycle events here

Simple webcam call

pc.on('localStreamAdded', function (stream) {
  var local = $('#local')[0];
  local.src = URL.createObjectURL(stream);
});

pc.on('remoteStreamAdded', function (stream, peer) {
  var element = videoTemplate.clone();
  element.attr({
    'class': peer,
    'src': URL.createObjectURL(stream)
  });
  $('#remotes').append(element);
});

pc.on('localStreamRemoved', function () {
  var local = $('#local')[0];
  local.src = '';
});

pc.on('remoteStreamRemoved', function (peer) {
  var remote = $('.' + peer);
  remote.remove();
});

$('#show').on('click', function () {
  spc.addLocalStream();
});

$('#hide').on('click', function () {
  spc.removeLocalStream();
});

Options

These options can be passed in to the PeerConnectionClient constructor

server

Where the signaling WebSockets server is located. Default: Current host root. So if you run the PeerConnectionClient from http://localhost:3000/, the PeerConnectionClient will try to connect to the WS server there.

room

The room that will be the context for connecting to peers. Your client will connect to all other clients in this room. Default: default

debug

Whether to console log negotiation events. Acceptable values are false, true, or "verbose", which will log full ICE connections. Default: false

API

Events

The PeerConnectionClient is an EventEmitter, meaning that you can use on(), emit(), and trigger() to listen to and fire events. There are several default events used to listen to the negotiation cycle, as well as many signaling events used to communicate with the signaling server.

.on('localStreamAdded', function(stream){})

Triggered when the local user has successfully added a stream to their local PeerConnections. Called with the MediaStream object that was captured. This object can be added to <video> elements.

.on('remoteStreamAdded', function(stream, peer){})

Triggered when a peer has successfully added a stream to their PeerConnection. Called with the MediaStream object that was captured and the peer's unique ID.

.on('localStreamRemoved', function(){})

Triggered when the local stream has been removed.

.on('remoteStreamRemoved', function(peer){})

Triggered when a remote stream has been removed. Called with the peer's unique ID.

.on('peerConnected', function(peer){})

Triggered when a peer has established and negotiated a PeerConnection. Can be used to add DataChannels, or just keep a list of users. Called with the peer's unique ID.

.on('peerDisconnected', function(peer){})

Triggered when a peer has disconnected. Can be used to keep track of which users are currently conected. Called with the peer's unique ID.

... Coming soon: DataChannels!

Methods

The PeerConnectionClient exposes many methods for interacting with peers connected to the WebSockets room.

addLocalStream(options)

Calls GetUserMedia to capture the browser's webcam and microphone. Passes through all standard GetUserMedia options, so can be used to capture just audio or video if necessary. Will trigger a user prompt asking for permission to access webcam and microphone.

removeLocalStream()

Removes the local stream from all PeerConnections and revoke microphone and video access.

disconnectConnection(id)

Disconnects a peer with the given ID, closing and removing the PeerConnection. If the connection had a MediaStream, it will also close and remove the stream.

License

Copyright (c) 2015 Tom Lagier [email protected]

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.