No way to know whether to create a room, or join one

[mvayngrib]

One of the current problems I'm experiencing with RTCMultiConnection-v1.2.js with the socketio-over-nodejs server is the lack of a proper way to establish a session. I'm currently using the hack that waits 5 seconds to see if it gets a session invite, otherwise it creates a new channel, but it's pretty unreliable, especially with a slow connection.

I feel like there should be a way to ask the server - "does this room exist?" - like you do with Firebase. Otherwise the two people who want to chat have to go in one at a time, which is not always practical. And a 5 second wait is quite long...especially when testing over and over :)

[imomin]

I am new to node.js and WebRTC and I started playing with it last night, I have similar thoughts, I was wondering if there is a way to remove dependency of Firebase.

I came up with this idea (not tested)
In signaler.js add var rooms = [];
and add

//expects query param id eg. http://localhost:8888/isRoomExists?id=blahblah
app.get('/isRoomExists', function (req, res) {
res.setHeader('Content-Type', 'application/json');
res.send(rooms.indexOf(req.query.id) > -1);
});
//expects query param id eg. http://localhost:8888/roomAdd?id=blahblah
app.get('/roomAdd', function (req, res) {
res.setHeader('Content-Type', 'application/json');
var roomId = req.query.id;
if(rooms.indexOf(roomId) == -1){
rooms.push(roomId);
res.send(roomId);
}
else {
//may be throw error
res.send(roomId);
}
});
//expects query param id eg. http://localhost:8888/roomRemove?id=blahblah
app.get('/roomRemove', function (req, res) {
res.setHeader('Content-Type', 'application/json');
var roomId = req.query.id;
if(rooms.indexOf(req.query.id) > -1){
rooms.splice(rooms.indexOf(req.query.id),1);
}
res.send(true);
});

[muaz-khan]

function testChannelPresence(channel) {
    var socket = io.connect('/');

    socket.on('presence', function (isChannelPresent) {
            console.log('is channel present', isChannelPresent);
            if (!isChannelPresent) playRoleOfSessionInitiator();
        });

    socket.emit('presence', channel);
}
testChannelPresence('default-channel');

[mvayngrib]

cool, thanks :)

I know I asked for this functionality...but thinking about it now, it would save a trip to the server if you could call 'new-channel' and have the server either
a) create a new channel IFF it doesn't already exist, or
b) connect to the channel if it already does

[kooler]

Is it possible to make such kind of trick for connections based on Firebase?

[muaz-khan]

Are you meant something like this?

channelToTest = 'default-channel';
new Firebase('https://chat.firebaseIO.com/' + channelToTest).once('value', function (data) {
    var isChannelPresent = data.val() != null;
    if (!isChannelPresent) playRoleOfSessionInitiator();

    console.log('is channel present', isChannelPresent);
});

[kooler]

Yep, exactly, works great. Thanks!

[zdfs]

The Firebase method doesn't seem to work with 1.3. Should it?

[muaz-khan]

@zdfs Are you meant "unable to detect presence of the channel".....or....?

Did you try something like this?

channelToTest = location.hash.substr(1) || 'another-channel';

new Firebase('https://chat.firebaseIO.com/' + channelToTest).once('value', function (data) {
    var isChannelPresent = data.val() != null;

    // if no channel present; open new session
    if (!isChannelPresent) connection.open('a-session-id');

    // else join existing session
    else connection.connect('a-session-id');
});

[zdfs]

Yeah. data.val() always returns null in 1.3. It works correctly in 1.2.

[muaz-khan]

It works; session-id must be same for all three cases:

1. For session initiator e.g. connection.open('session-id')
2. For session participants e.g. connection.connect('session-id')
3. And for detecting presence of the session e.g. new window.Firebase('https://chat.firebaseIO.com/' + sessionid)

var sessionid = 'session-id';
var connection = new RTCMultiConnection();

connection.session = {
    audio: true,
    video: true
};

connection.onstream = function (e) {
    document.body.appendChild(e.mediaElement);
};

new window.Firebase('https://chat.firebaseIO.com/' + sessionid).once('value', function (data) {
    var isRoomPresent = data.val() != null;
    if (!isRoomPresent) connection.open(sessionid);
    else connection.connect(sessionid);

    console.debug('room is present?', isRoomPresent);
});

By default, v1.3 uses chat.firebaseIO.com i.e. chat key. You can override it too:

// overriding for session initiation
connection.firebase = 'signaling';

// presence detection
new window.Firebase('https://signaling.firebaseIO.com/' + sessionid).once(....);

You can see that signaling key is used both for session initiation and presence detection.

[zdfs]

I'll take a look tomorrow. Thanks for your input!

[zdfs]

Turns out that https://rtcweb.firebaseIO.com doesn't behave like https://chat.firebaseIO.com. Once I switched the url, behavior returned to normal.

Will probably switch to my own socket IO implementation at some point, but will need the Firebase service for a bit longer. Thanks for your help!

[muaz-khan]

Do you know, firebase can behave like socket.io over node.js too!

new Firebase('https://YOURINSTANCE.firebaseio.com').on('value', function(snap) { 
     // here is the data transferred from the sender!
    var data = snap.val();

    // will never keep data on firebase servers!
    snap.ref().remove(); 
});

I'm using same technique in RTCMultiConnection-v1.4 and DataChannel-v1.1.

Their set function allow us overwrite existing data; however push seems better because we usually share different kinds of data e.g. ice candidates; session descriptions; presence/notifications etc. (simultaneously)

[ghost]

@muaz-khan Your proposed solution, which is working well with RTCMultiConnection-1.3, fails when using RTCMultiConnection-1.4. How can we then check whether to create or join a room?

[muaz-khan]

RTCMultiConnection-v1.4 working demos coming soon. E.g.

1. All-in-One test
2. Video Conferencing & File Sharing & Text Chat
3. Renegotiation
4. Auto Session Initiation (i.e. auto join/create rooms)

etc.

Following code works well with v1.4 too; to detect presence of the room; and create/join room accordingly:

new window.Firebase('https://chat.firebaseIO.com/' + sessionid).once('value', function (data) {
    var isRoomPresent = data.val() != null;
    if (!isRoomPresent) connection.open(sessionid);
    else connection.connect(sessionid);

    console.debug('room is present?', isRoomPresent);
});

[softi89]

can I replace Firebase('https://chat.firebaseIO.com/' + sessionid) with node.js signaling server