webrtc configration return null value - webrtc

Question

I am implementing webrtc for peerconnection but not working. when i debug this code then i saw it is not coming in
theirConnection.onaddstream = function (e) {
theirVideo.src = window.URL.createObjectURL(e.stream);
};
block. please let me know where i have done wrong? I am using this on my local system and with one webcam only.
function startPeerConnection(stream) {
var configuration = {
"iceServers": [{ "url": "stun:127.0.0.1:8080" }]
};
yourConnection = new mozRTCPeerConnection(configuration);
theirConnection = new mozRTCPeerConnection(configuration);
// Setup stream listening
theirConnection.onaddstream = function (e) {
theirVideo.src = window.URL.createObjectURL(e.stream);
};
// Setup ice handling
yourConnection.onicecandidate = function (event) {
if (event.candidate) {
theirConnection.addIceCandidate(new RTCIceCandidate(event.candidate));
}
};
theirConnection.onicecandidate = function (event) {
if (event.candidate) {
yourConnection.addIceCandidate(new RTCIceCandidate(event.candidate));
}
};
// Begin the offer
yourConnection.createOffer(function (offer) {
yourConnection.setLocalDescription(offer);
theirConnection.setRemoteDescription(offer);
theirConnection.createAnswer(function (offer) {
theirConnection.setLocalDescription(offer);
yourConnection.setRemoteDescription(offer);
});
});
}

Answer 1

You're calling the promise methods. The problem is literally that you're not checking for errors.
Specifically: The legacy callback methods you seek expect at least two arguments: a success callback, and a failure callback.
Without a failure callback, WebIDL name-overloading calls the newer promise methods instead, which take no callbacks and return a promise instead.
Either pass in the required error callbacks everywhere, e.g.:
yourConnection.createOffer(offer => { ... }, err => console.log(err));
Or better, avoid the legacy methods altogether:
function startPeerConnection(stream) {
var config = { iceServers: [{ urls: "stun:127.0.0.1:8080" }] };
yours = new RTCPeerConnection(config);
theirs = new RTCPeerConnection(config);
theirs.onaddstream = e => theirVideo.srcObject = e.stream;
yours.onicecandidate = e => theirs.addIceCandidate(e.candidate);
theirs.onicecandidate = e => yours.addIceCandidate(e.candidate);
yours.addStream(stream); // <-- don't forget
return yours.createOffer()
.then(offer => Promise.all([yours.setLocalDescription(offer),
theirs.setRemoteDescription(offer)]))
.then(() => theirs.createAnswer())
.then(answer => Promise.all([theirs.setLocalDescription(answer),
yours.setRemoteDescription(answer)]));
}
navigator.mediaDevices.getUserMedia({video: true, audio: true})
.then(stream => startPeerConnection(stream))
.catch(e => console.log(e));
<video id="theirVideo" height="120" width="160" autoplay></video>
<script src="https://webrtc.github.io/adapter/adapter-latest.js"></script>
And always check for errors. A createOffer error told me you'd forgotten .addStream(stream).
The promise API is available natively in Firefox, and through adapter.js in Chrome.