Reliable Signaler

It is a node.js and socket.io based reliable signaling implementation. Remember, reliable doesn't mean "scalable"; reliable simply means that it auto reconnects in any kind of failure or internet disconnect. It is having following features:

Auto reconnects if node.js gets down out of any reason.
Auto reconnects if internet connection disconnects.
It provides custom-signaling for your RTCMultiConnection and DataChannel applications!

npm install reliable-signaler

How it works?

You can store a room-id on server using createNewRoomOnServer method.
You can get that room-id using getRoomFromServer method.

How to use?

In your Node.js server, invoke require('reliable-signaler') and pass HTTP-Server object.
In your HTML file, link this script: /reliable-signaler/signaler.js
In your <script> tag, invoke initReliableSignaler constructor.
Invoke createNewRoomOnServer method for room-moderator.
Invoke getRoomFromServer method from room-participants (multiple participants).

Demos

rtcmulticonnection-client:
datachannel-client:
videoconferencing-client:

# install rtcmulticonnection-client
npm install rtcmulticonnection-client
node ./node_modules/rtcmulticonnection-client/server.js

# or intall datachannel-client
npm install datachannel-client
node ./node_modules/datachannel-client/server.js

# or intall videoconferencing-client
npm install videoconferencing-client
node ./node_modules/videoconferencing-client/server.js

Now open localhost port:8080.

1st Step: Node.js Server-side code

To use it in your node.js code: (required)

javascript

var httpServer = require('http').createServer(callback);

require('reliable-signaler')(httpServer || expressServer || portNumber, {
    // for custom socket handlers
    socketCallback: function(socket) {
        socket.on('custom-handler', function(message) {
            socket.broadcast.emit('custom-handler', message);
        });
    }
});

Constructor of the module reliable-signaler takes an config object where you can pass socketCallback and other configurations:

javascript

var config = {
    socketCallback: function(socket) {}
};
require('reliable-signaler')(httpServer, config);

*. socketCallback: If you want to attach custom handlers over socket object.

2nd Step: Browser-side code

To use it in the browser: (required)

htm

<script src="/reliable-signaler/signaler.js"></script>

And your client-side javascript code:

javascript

var connection = new RTCMultiConnection();

// invoke "initReliableSignaler" and pass "connection" or "channel" object
var signaler = initReliableSignaler(connection, 'http://domain:port/');

Call createNewRoomOnServer method as soon as you'll call open method. You can even call createNewRoomOnServer earlier than open however it isn't suggested:

For RTCMultiConnection:

javascript

// for data-only sessions
connection.open();
signaler.createNewRoomOnServer(connection.sessionid);

// or (not recommended)
signaler.createNewRoomOnServer(connection.sessionid, function() {
    connection.open();
});

// or --- recommended.
connection.open({
    onMediaCaptured: function() {
        signaler.createNewRoomOnServer(connection.sessionid);
    }
});

For DataChannel:

javascript

channel.open('room-id');
signaler.createNewRoomOnServer('room-id', successCallback);

For participants, call getRoomFromServer method:

javascript

// RTCMultiConnection
signaler.getRoomFromServer('sessioin-id', function(roomid) {
    // invoke "join" in callback
    connection.join({
        sessionid: roomid,
        userid: roomid,
        extra: {},
        session: connection.session
    });
    
    // or simply
    connection.join(roomid);
    
    // or
    connection.connect(roomid);
});

// DataChannel
signaler.getRoomFromServer('sessioin-id', function(roomid) {
    channel.join({
        id: roomid,
        owner: roomid
    });
    
    // or
    channel.connect(roomid);
});

Complete Client-Side Example for RTCMultiConnection

html

<script src="/reliable-signaler/signaler.js"></script>
<script>
var connection = new RTCMultiConnection();

var signaler = initReliableSignaler(connection, '/');

btnOpenRoom.onclick = function() {
    connection.channel = connection.sessionid = connection.userid = sessionid;
    connection.open({
        onMediaCaptured: function() {
            signaler.createNewRoomOnServer(connection.sessionid);
        }
    });
};

btnJoinRoom.onclick = function() {
    signaler.getRoomFromServer(roomid, function(roomid){
        connection.channel = connection.sessionid = roomid;
        connection.join({
            sessionid: roomid,
            userid: roomid,
            extra: {},
            session: connection.session
        });
    });
};
</script>

Complete Client-Side Example for DataChannel

html

<script src="/reliable-signaler/signaler.js"></script>
<script>
var channel = new DataChannel();

var signaler = initReliableSignaler(channel, '/');

btnOpenRoom.onclick = function() {
    signaler.createNewRoomOnServer(roomid, function() {
        channel.channel = channel.userid = roomid;
        channel.open(roomid);
    });
};

btnJoinRoom.onclick = function() {
    signaler.getRoomFromServer(roomid, function(roomid){
        channel.channel = roomid;
        channel.join({
            id: roomid,
            owner: roomid
        });
    });
};
</script>

API Reference

Constructor takes either RTCMultiConnection instance or a config object:

javascript

# 1st option: Pass RTCMultiConnection object
var signaler = initReliableSignaler(connection);

# 2nd option: Pass "config" object
var signaler = initReliableSignaler(connection, '/');

initReliableSignaler global-function exposes/returns 3-objects:

socket
createNewRoomOnServer
getRoomFromServer

javascript

// "socket" object
signaler.socket.emit('message', 'hello');

// "createNewRoomOnServer" method
signaler.createNewRoomOnServer(connection.sessionid, successCallback);

// "getRoomFromServer" object
signaler.getRoomFromServer('sessioin-id', callback);

`createNewRoomOnServer`

This method simply takes sessioin-id and stores in node.js server. You can even pass successCallback.

javascript

signaler.createNewRoomOnServer(roomid, successCallback);

`getRoomFromServer`

This method looks for active sessioin-id in node.js server. Node.js server will fire callback only when session is found.

If session is absent, then node.js server will wait until someone opens that session; and node.js will fire getRoomFromServer-callback as soon a session is opened.

javascript

signaler.getRoomFromServer(roomid, successCallback);

License

Reliable-Signaler is released under MIT licence . Copyright (c) Muaz Khan.