#Socket.io-Peer

This module provides an easy and reliable way to setup a WebRTC connection between peers and communicate using events (the socket.io-protocol). It is a fork of the socket.io-p2p package.

Socket.IO is used to transport signalling data and as a fallback for clients where WebRTC PeerConnection is not supported.

How to use

Create a socket connection, pass it to Peer. On the Client:

var Peer = require('socket.io-peer');
var io = require('socket.io-client');
var socket = io();

var peer = new Peer(socket);

peer.on('ready', function(){
  peer.usePeerConnection = true;
  peer.emit('peer-obj', { peerId: peerId });
})

// this event will be triggered over the socket transport
// until `usePeerConnection` is set to `true`
peer.on('peer-msg', function(data){
  console.log(data);
});

If you're not using browserify, then use the included standalone file socketiopeer.min.js. This exports a Peer constructor on window.

On the server, use the socket.io-peer-server to take care of signalling. All clients who support WebRTC data connections will exchange signalling data via the default / namespace.

var server = require('http').createServer();
var io = require('socket.io')(server);
var peer = require('socket.io-peer-server').Server;
io.use(peer);
server.listen(3030);

WebRTC Peer connections can also be established by exchanging signalling data within a socket.io room. Do this by calling the peer server within the connection callback:

var server = require('http').createServer();
var io = require('socket.io')(server);
var peer = require('socket.io-peer-server').Server;
server.listen(3030);

io.on('connection', function(socket){
  clients[socket.id] = socket;
  socket.join(roomName);
  peer(socket, null, room);
});

See chat app for full example.

API

peer = new Peer(socket, opts, cb)

Create a new socket.io-peer connection.

The opts object can include options for setup of the overall socket.io-peer connection as well as options for the individual peers - specified using peerOpts.

• numClients - max number of peers each client can connect to; 5 by default.
• autoUpgrade - upgrade to a peer connection (from a socket.io one) when peers are ready; true by default
• peerOpts - object of options to be passed to underlying peers. See here for currently supported options. See here for an example.

cb is an optional callback. Called when connection is upgraded to a WebRTC connection.

peersocket.on('upgrade', function (data) {})

Triggered when Peer connection is converted to a WebRTC one.

peersocket.on('peer-error', function (data) {})

Triggered when a PeerConnection object errors during signalling.

Roadmap of development

• Support for packets containing multiple binary blobs - packets can only contain one blob in this version
• Allow a peer to act as a relay between peers that don't support PeerConnection and those that do.

PRs and issue reports are most welcome.