rtc-quickconnect

This is a high level helper module designed to help you get up
an running with WebRTC really, really quickly. By using this module you
are trading off some flexibility, so if you need a more flexible
configuration you should drill down into lower level components of the
rtc.io suite. In particular you should check out
rtc.


 

Example Usage

In the simplest case you simply call quickconnect with a single string
argument which tells quickconnect which server to use for signaling:

``js
var quickconnect = require('rtc-quickconnect');

quickconnect('https://switchboard.rtc.io/', { room: 'qc-simple-demo' })
.on('call:started', function(id, pc, data) {
console.log('we have a new connection to: ' + id);
});

`

The first argument to quickconnect is the URL of the signalling server, the second is a set of options given as a JSON object.
Valid options are described below.

Events

The following events are emitted from the signalling object created by calling quickconnect(). Additionally, any of the underlying signaller events can also be used.

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The peer level events provided in quickconnect provide you the ability to tap into the various stages of the lifecycle for connecting with a peer, before the connection actually migrates to the status of a connected "call".

- peer:connect => function(id, peerconnection, data)

The peer:connect event is emitted when we first create a connection to a discovered peer. The peerconnection argument is a standard RTCPeerConnection instance.

- peer:couple => funtion(id, peerconnection, data, monitor)

The peer:couple event is emitted when once quickconnect has coupled to its remote counterpart.

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A "call" in quickconnect is equivalent to an established RTCPeerConnection between this quickconnect instance a remote peer.

- call:started => function(id, peerconnection, data)

Triggered once a peer connection has been established been established between this quickconnect instance and another.

- call:ended => function(id)

Triggered when a peer connection has been closed. This may be due to the peer connection itself indicating that it has been closed, or we may have lost connection with the remote signaller and the connection has timed out.

- call:expired => function(id)

Triggered when a peer connection is timed out due to the expiry of the heartbeat to the remote peer. Note that this event is thrown before (and in addition to) the more generic call:ended event.

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- channel:opened => function(id, datachannel, data)

The channel:opened event is triggered whenever an RTCDataChannel has been opened (it's ready to send data) to a remote peer.

- channel:opened:%label% => function(id, datachannel, data)

This is equivalent of the channel:opened event, but only triggered for a channel with label %label%. For example:

`js
quickconnect('https://switchboard.rtc.io/', { room: 'test' })
.createDataChannel('foo')
.createDataChannel('bar')
.on('channel:opened:foo', function(id, dc) {
console.log('channel foo opened for peer: ' + id);
});
`

In the case above the console message would only be displayed for the foo channel once open, and when the bar channel is opened no handler would be invoked.

- channel:closed => function(id, datachannel, label)

Emitted when the channel has been closed, works when a connection has been closed or the channel itself has been closed.

- channel:closed:%label% => function(id, datachannel, label)

The label specific equivalent of channel:closed.

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- stream:added => function(id, stream, data)

The stream:added event is triggered when an RTCPeerConnection has successfully been established to another peer that contains remote streams. Additionally, if you are using quickconnect in its "reactive" mode then you will also receive stream:added events as streams are dynamically added to the connection by the remote peer.

- stream:removed => function(id)

As per the stream:added event but triggered when a stream has been removed.

Example Usage (using data channels)

When working with WebRTC data channels, you can call the createDataChannel function helper that is attached to the object returned from the quickconnect call. The createDataChannel function signature matches the signature of the RTCPeerConnection createDataChannel function.

At the minimum it requires a label for the channel, but you can also pass through a dictionary of options that can be used to fine tune the data channel behaviour. For more information on these options, I'd recommend having a quick look at the WebRTC spec:

If in doubt, I'd recommend not passing through options.

`js
var freeice = require('freeice');
var quickconnect = require('rtc-quickconnect');
var opts = {
room: 'qcexample-dctest',
// debug: true,
iceServers: freeice()
};

quickconnect('https://switchboard.rtc.io/', opts)
// tell quickconnect we want a datachannel called test
.createDataChannel('test')
// when the test channel is open, let us know
.on('channel:opened:test', function(id, dc) {
dc.onmessage = function(evt) {
console.log('peer ' + id + ' says: ' + evt.data);
};

console.log('test dc open for peer: ' + id);
dc.send('hi');
});

`

Example Usage (using captured media)

Another example is displayed below, and this example demonstrates how to use rtc-quickconnect to create a simple video conferencing application:

`js
var quickconnect = require('rtc-quickconnect');
var crel = require('crel');
var capture = require('rtc-capture');
var attach = require('rtc-attach');
var qsa = require('fdom/qsa');
var plugins = [
require('rtc-plugin-temasys')
];

// create containers for our local and remote video
var local = crel('div', { class: 'local' });
var remote = crel('div', { class: 'remote' });
var peerMedia = {};

// once media is captured, connect
capture({ audio: true, video: true }, { plugins: plugins }, function(err, localStream) {
if (err) {
return console.error('could not capture media: ', err);
}

// render the local media
attach(localStream, { plugins: plugins }, function(err, el) {
local.appendChild(el);
});

// initiate connection
quickconnect('https://switchboard.rtc.io/', { room: 'conftest', plugins: plugins })
// broadcast our captured media to other participants in the room
.addStream(localStream)
// when a peer is connected (and active) pass it to us for use
.on('call:started', function(id, pc, data) {
attach(pc.getRemoteStreams()[0], { plugins: plugins }, function(err, el) {
if (err) return;

el.dataset.peer = id;
remote.appendChild(el);
});
})
// when a peer leaves, remove teh media
.on('call:ended', function(id) {
qsa('*[data-peer="' + id + '"]', remote).forEach(function(el) {
el.parentNode.removeChild(el);
});
});
});

/ extra code to handle dynamic html and css creation /

// add some basic styling
document.head.appendChild(crel('style', [
'.local { position: absolute; right: 10px; }',
'.local video { max-width: 200px; }'
].join('\n')));

// add the local and remote elements
document.body.appendChild(local);
document.body.appendChild(remote);

`

Regarding Signalling and a Signalling Server

Signaling is an important part of setting up a WebRTC connection and for
our examples we use our own test instance of the
rtc-switchboard. For your
testing and development you are more than welcome to use this also, but
just be aware that we use this for our testing so it may go up and down
a little. If you need something more stable, why not consider deploying
an instance of the switchboard yourself - it's pretty easy :)

Reference

`
quickconnect(signalhost, opts?) => rtc-sigaller instance (+ helpers)
`

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The options provided to the rtc-quickconnect module function influence the
behaviour of some of the underlying components used from the rtc.io suite.

Listed below are some of the commonly used options:

- ns (default: '')

An optional namespace for your signalling room. While quickconnect
will generate a unique hash for the room, this can be made to be more
unique by providing a namespace. Using a namespace means two demos
that have generated the same hash but use a different namespace will be
in different rooms.

- room (default: null) _added 0.6_

Rather than use the internal hash generation
(plus optional namespace) for room name generation, simply use this room
name instead. __NOTE:__ Use of the room option takes precendence over
ns.

- debug (default: false)

- plugins (default: '')

An optional array of rtc-plugins to add, e.g. add Temasys plugin as list
item plugins = [ require('rtc-plugin-temasys')];


Write rtc.io suite debug output to the browser console.

- expectedLocalStreams (default: not specified) _added 3.0_

By providing a positive integer value for this option will mean that
the created quickconnect instance will wait until the specified number of
streams have been added to the quickconnect "template" before announcing
to the signaling server.

- manualJoin (default: false)

Set this value to true if you would prefer to call the join function
to connecting to the signalling server, rather than having that happen
automatically as soon as quickconnect is ready to.

#### Options for Peer Connection Creation

Options that are passed onto the
rtc.createConnection
function:

- iceServers

This provides a list of ice servers that can be used to help negotiate a
connection between peers.

- constraints (default: '')

An optional RTCConstraints object that is handed to the RTCPeerConnection call, e.g.
constraints: {"optional": [ {'googIPv6': 'false'} ] } or
constraints: {"optional": [ {RtpDataChannels: true} ] }

- sdpfilter (default '')

An optional function to provide for sdp munging, e.g.
sdpfilter: function(sdp) { console.log('filtering sdp'); return limitBandwidthSDP(sdp);}


#### Options for P2P negotiation

Under the hood, quickconnect uses the
rtc/couple logic, and the options
passed to quickconnect are also passed onto this function.

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The following are functions that are patched into the rtc-signaller
instance that make working with and creating functional WebRTC applications
a lot simpler.

#### addStream

`
addStream(stream:MediaStream) => qc
`

Add the stream to active calls and also save the stream so that it
can be added to future calls.


#### addTrack

The addTrack function terminates do the pure WebRTC addTrack logic.


#### replaceTrack

The replaceTrack function call web WebRTC API for replaceTrack (sender)
replaceTrack(newTrack, oldTrackId)


#### endCall

The endCall function terminates the active call with the given ID.
If a call with the call ID does not exist it will do nothing.


#### endCalls()

The endCalls function terminates all the active calls that have been
created in this quickconnect instance. Calling endCalls does not
kill the connection with the signalling server.


#### close()

The close function provides a convenient way of closing all associated
peer connections. This function simply uses the endCalls function and
the underlying leave function of the signaller to do a "full cleanup"
of all connections.

#### createDataChannel(label, config)

Request that a data channel with the specified label is created on
the peer connection. When the data channel is open and available, an
event will be triggered using the label of the data channel.

For example, if a new data channel was requested using the following
call:

`js
var qc = quickconnect('https://switchboard.rtc.io/').createDataChannel('test');
`

Then when the data channel is ready for use, a test:open event would
be emitted by qc.

#### join()

The join function is used when manualJoin is set to true when creating
a quickconnect instance. Call the join function once you are ready to
join the signalling server and initiate connections with other people.

#### get(name)

The get function returns the property value for the specified property name.

#### getLocalStreams()

Return a copy of the local streams that have currently been configured

#### reactive()

Flag that this session will be a reactive connection.

#### removeStream

`
removeStream(stream:MediaStream)
`

Remove the specified stream from both the local streams that are to
be connected to new peers, and also from any active calls.

#### requestChannel

`
requestChannel(targetId, label, callback)
`

This is a function that can be used to respond to remote peers supplying
a data channel as part of their configuration. As per the receiveStream
function this function will either fire the callback immediately if the
channel is already available, or once the channel has been discovered on
the call.

#### requestStream

`
requestStream(targetId, idx, callback)
`

Used to request a remote stream from a quickconnect instance. If the
stream is already available in the calls remote streams, then the callback
will be triggered immediately, otherwise this function will monitor
stream:added events and wait for a match.

In the case that an unknown target is requested, then an exception will
be thrown.

#### profile(data)

Update the profile data with the attached information, so when
the signaller announces it includes this data in addition to any
room and id information.

#### waitForCall

`
waitForCall(targetId, callback)
`

Wait for a call from the specified targetId. If the call is already
active the callback will be fired immediately, otherwise we will wait
for a call:started event that matches the requested targetId`

License(s)

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Copyright 2015 National ICT Australia Limited (NICTA)

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.