/**
* The list of DataChannel states that would be trigged.
* @attribute DATA_CHANNEL_STATE
* @type JSON
* @param {String} CONNECTING The DataChannel is attempting to establish a connection.
* @param {String} OPEN The DataChannel connection is established.
* @param {String} CLOSING The DataChannel is closing the connection.
* @param {String} CLOSED The DataChannel connection is closed.
* @param {String} ERROR The DataChannel is thrown with an exception during connection.
* @readOnly
* @component DataChannel
* @for Skylink
* @since 0.1.0
*/
Skylink.prototype.DATA_CHANNEL_STATE = {
CONNECTING: 'connecting',
OPEN: 'open',
CLOSING: 'closing',
CLOSED: 'closed',
ERROR: 'error'
};
/**
* The flag that indicates if DataChannel should be enabled.
* @attribute _enableDataChannel
* @type Boolean
* @default true
* @private
* @required
* @component DataChannel
* @for Skylink
* @since 0.3.0
*/
Skylink.prototype._enableDataChannel = true;
/**
* Stores the DataChannel received or created with peers.
* @attribute _dataChannels
* @param {Object} <peerId> The DataChannel associated with peer.
* @type JSON
* @private
* @required
* @component DataChannel
* @for Skylink
* @since 0.2.0
*/
Skylink.prototype._dataChannels = {};
/**
* Creates and binds events to a SCTP DataChannel.
* @method _createDataChannel
* @param {String} peerId The peerId to tie the DataChannel to.
* @param {Object} [dataChannel] The datachannel object received.
* @trigger dataChannelState
* @return {Object} New DataChannel with events.
* @private
* @component DataChannel
* @for Skylink
* @since 0.5.5
*/
Skylink.prototype._createDataChannel = function(peerId, dc) {
var self = this;
var channelName = (dc) ? dc.label : peerId;
var pc = self._peerConnections[peerId];
if (window.webrtcDetectedDCSupport !== 'SCTP' &&
window.webrtcDetectedDCSupport !== 'plugin') {
log.warn([peerId, 'RTCDataChannel', channelName, 'SCTP not supported']);
return;
}
var dcHasOpened = function () {
log.log([peerId, 'RTCDataChannel', channelName, 'Datachannel state ->'], 'open');
log.log([peerId, 'RTCDataChannel', channelName, 'Binary type support ->'], dc.binaryType);
self._dataChannels[peerId] = dc;
self._trigger('dataChannelState', dc.readyState, peerId);
};
if (!dc) {
try {
dc = pc.createDataChannel(channelName);
self._trigger('dataChannelState', dc.readyState, peerId);
self._checkDataChannelReadyState(dc, dcHasOpened, self.DATA_CHANNEL_STATE.OPEN);
} catch (error) {
log.error([peerId, 'RTCDataChannel', channelName,
'Exception occurred in datachannel:'], error);
self._trigger('dataChannelState', self.DATA_CHANNEL_STATE.ERROR, peerId, error);
return;
}
} else {
if (dc.readyState === self.DATA_CHANNEL_STATE.OPEN) {
dcHasOpened();
} else {
dc.onopen = dcHasOpened;
}
}
dc.onerror = function(error) {
log.error([peerId, 'RTCDataChannel', channelName, 'Exception occurred in datachannel:'], error);
self._trigger('dataChannelState', self.DATA_CHANNEL_STATE.ERROR, peerId, error);
};
dc.onclose = function() {
log.debug([peerId, 'RTCDataChannel', channelName, 'Datachannel state ->'], 'closed');
dc.hasFiredClosed = true;
// give it some time to set the variable before actually closing and checking.
setTimeout(function () {
// if closes because of firefox, reopen it again
// if it is closed because of a restart, ignore
if (pc ? !pc.dataChannelClosed : false) {
log.debug([peerId, 'RTCDataChannel', channelName, 'Re-opening closed datachannel in ' +
'on-going connection']);
self._dataChannels[peerId] = self._createDataChannel(peerId);
} else {
self._closeDataChannel(peerId);
self._trigger('dataChannelState', self.DATA_CHANNEL_STATE.CLOSED, peerId);
}
}, 100);
};
dc.onmessage = function(event) {
self._dataChannelProtocolHandler(event.data, peerId, channelName);
};
return dc;
};
/**
* Checks and triggers provided callback when the current DataChannel readyState
* is the same as the readyState provided.
* @method _checkDataChannelReadyState
* @param {Object} dataChannel The DataChannel readyState to check on.
* @param {Function} callback The callback to be fired when DataChannel readyState
* matches the readyState provided.
* @param {String} readyState The DataChannel readystate to match. [Rel: DATA_CHANNEL_STATE]
* @private
* @component DataChannel
* @for Skylink
* @since 0.5.5
*/
Skylink.prototype._checkDataChannelReadyState = function(dc, callback, state) {
var self = this;
if (!self._enableDataChannel) {
log.debug('Datachannel not enabled. Returning callback');
callback();
return;
}
// fix for safari showing datachannel as function
if (typeof dc !== 'object' && (window.webrtcDetectedBrowser === 'safari' ?
typeof dc !== 'object' && typeof dc !== 'function' : true)) {
log.error('Datachannel not provided');
return;
}
if (typeof callback !== 'function'){
log.error('Callback not provided');
return;
}
if (!state){
log.error('State undefined');
return;
}
self._wait(function () {
log.log([null, 'RTCDataChannel', dc.label, 'Firing callback. ' +
'Datachannel state has met provided state ->'], state);
callback();
}, function () {
return dc.readyState === state;
});
};
/**
* Sends a Message via the peer's DataChannel based on the peerId provided.
* @method _sendDataChannelMessage
* @param {String} peerId The peerId associated with the DataChannel to send from.
* @param {JSON} data The Message data to send.
* @trigger dataChannelState
* @private
* @component DataChannel
* @for Skylink
* @since 0.5.2
*/
Skylink.prototype._sendDataChannelMessage = function(peerId, data) {
var dc = this._dataChannels[peerId];
if (!dc) {
log.error([peerId, 'RTCDataChannel', null, 'Datachannel connection ' +
'to peer does not exist']);
return;
} else {
if (dc.readyState === this.DATA_CHANNEL_STATE.OPEN) {
var dataString = (typeof data === 'object') ? JSON.stringify(data) : data;
log.debug([peerId, 'RTCDataChannel', dc.label, 'Sending to peer ->'],
(data.type || 'DATA'));
dc.send(dataString);
} else {
log.error([peerId, 'RTCDataChannel', dc.label, 'Datachannel is not opened'],
'State: ' + dc.readyState);
this._trigger('dataChannelState', this.DATA_CHANNEL_STATE.ERROR,
peerId, 'Datachannel is not ready.\nState is: ' + dc.readyState);
}
}
};
/**
* Closes the peer's DataChannel based on the peerId provided.
* @method _closeDataChannel
* @param {String} peerId The peerId associated with the DataChannel to be closed.
* @private
* @component DataChannel
* @for Skylink
* @since 0.1.0
*/
Skylink.prototype._closeDataChannel = function(peerId) {
var self = this;
var dc = self._dataChannels[peerId];
if (dc) {
if (dc.readyState !== self.DATA_CHANNEL_STATE.CLOSED) {
dc.close();
} else {
if (!dc.hasFiredClosed && window.webrtcDetectedBrowser === 'firefox') {
self._trigger('dataChannelState', self.DATA_CHANNEL_STATE.CLOSED, peerId);
}
}
delete self._dataChannels[peerId];
log.log([peerId, 'RTCDataChannel', dc.label, 'Sucessfully removed datachannel']);
}
};