example: data-channels-create

examples/data-channels-create/jsfiddle/demo.js

@@ -5,38 +5,50 @@ let log = msg => {
   document.getElementById('logs').innerHTML += msg + '<br>'
 }
 
-let sendChannel = pc.createDataChannel()
+// let sendChannel = pc.createDataChannel('foo')
-console.log(sendChannel.id)
+// sendChannel.onclose = () => console.log('sendChannel has closed')
-sendChannel.onclose = () => console.log('sendChannel has closed')
+// sendChannel.onopen = () => console.log('sendChannel has opened')
-sendChannel.onopen = () => console.log('sendChannel has opened')
+// sendChannel.onmessage = e => log(`sendChannel got '${e.data}'`)
-sendChannel.onmessage = e => log(`sendChannel got '${e.data}'`)
 
+pc.onsignalingstatechange = e => log(pc.signalingState)
 pc.oniceconnectionstatechange = e => log(pc.iceConnectionState)
-
+pc.onicecandidate = event => {
-pc.onnegotiationneeded = e =>
+  if (event.candidate === null) {
-  pc.createOffer({ }).then(d => {
+    document.getElementById('localSessionDescription').value = btoa(pc.localDescription.sdp)
-    document.getElementById('localSessionDescription').value = btoa(d.sdp)
-    return pc.setLocalDescription(d)
-  }).catch(log)
-
-window.sendMessage = () => {
-  let message = document.getElementById('message').value
-  if (message === '') {
-    return alert('Message must not be empty')
   }
-
-  sendChannel.send(message)
 }
 
+pc.ondatachannel = e => {
+  log('got dc')
+  dc = e.channel
+  dc.onclose = () => console.log('dc has closed')
+  dc.onopen = () => console.log('dc has opened')
+  dc.onmessage = e => log(`dc got '${e.data}'`)
+  window.sendMessage = () => {
+    let message = document.getElementById('message').value
+    if (message === '') {
+      return alert('Message must not be empty')
+    }
+
+    dc.send(message)
+  }
+}
+
+// pc.onnegotiationneeded = e =>
+//   pc.createOffer().then(d => pc.setLocalDescription(d)).catch(log)
+
+
+
 window.startSession = () => {
   let sd = document.getElementById('remoteSessionDescription').value
   if (sd === '') {
     return alert('Session Description must not be empty')
   }
 
-  try {
+  log(atob(sd))
-    pc.setRemoteDescription(new RTCSessionDescription({type: 'answer', sdp: atob(sd)}))
+  pc.setRemoteDescription(new RTCSessionDescription({type: 'offer', sdp: atob(sd)})).catch(log)
-  } catch (e) {
+
-    alert(e)
+  log("ss", pc.signalingState)
-  }
+  pc.createAnswer().then(d => pc.setLocalDescription(d)).catch(log)
+
 }

examples/data-channels-create/main.go

@@ -25,20 +25,6 @@ func randSeq(n int) string {
 }
 
 func main() {
-	reader := bufio.NewReader(os.Stdin)
-	rawSd, err := reader.ReadString('\n')
-	if err != nil && err != io.EOF {
-		panic(err)
-	}
-
-	fmt.Println("")
-	sd, err := base64.StdEncoding.DecodeString(rawSd)
-	if err != nil {
-		panic(err)
-	}
-
-	/* Everything below is the pion-WebRTC API, thanks for using it! */
-
 	// Create a new RTCPeerConnection
 	peerConnection, err := webrtc.New(webrtc.RTCConfiguration{
 		ICEServers: []webrtc.RTCICEServer{
@@ -57,8 +43,6 @@ func main() {
 		fmt.Printf("Connection State has changed %s \n", connectionState.String())
 	}
 
-	// TODO: We have to send the offer otherwise it's empty.
-
 	d, err := peerConnection.CreateDataChannel("data", nil)
 	if err != nil {
 		panic(err)
@@ -79,23 +63,28 @@ func main() {
 	}
 	d.Unlock()
 
-	// Set the remote SessionDescription
+	offer, err := peerConnection.CreateOffer(nil)
-	offer := webrtc.RTCSessionDescription{
-		Type: webrtc.RTCSdpTypeOffer,
-		Sdp:  string(sd),
-	}
-	if err := peerConnection.SetRemoteDescription(offer); err != nil {
-		panic(err)
-	}
-
-	// Sets the LocalDescription, and starts our UDP listeners
-	answer, err := peerConnection.CreateAnswer(nil)
 	if err != nil {
 		panic(err)
 	}
 
+	/* Signaling via STDIN */
+
 	// Get the LocalDescription and take it to base64 so we can paste in browser
-	fmt.Println(base64.StdEncoding.EncodeToString([]byte(answer.Sdp)))
+	fmt.Println(base64.StdEncoding.EncodeToString([]byte(offer.Sdp)))
+	sd := mustReadStdin()
+
+	/* --- */
+
+	// Set the remote SessionDescription
+	answer := webrtc.RTCSessionDescription{
+		Type: webrtc.RTCSdpTypeAnswer,
+		Sdp:  sd,
+	}
+	if err := peerConnection.SetRemoteDescription(answer); err != nil {
+		panic(err)
+	}
+
 	fmt.Println("Random messages will now be sent to any connected DataChannels every 5 seconds")
 	for {
 		time.Sleep(5 * time.Second)
@@ -108,3 +97,18 @@ func main() {
 		}
 	}
 }
+
+func mustReadStdin() string {
+	reader := bufio.NewReader(os.Stdin)
+	rawSd, err := reader.ReadString('\n')
+	if err != nil && err != io.EOF {
+		panic(err)
+	}
+
+	fmt.Println("")
+	sd, err := base64.StdEncoding.DecodeString(rawSd)
+	if err != nil {
+		panic(err)
+	}
+	return string(sd)
+}

signaling.go

@@ -254,7 +254,6 @@ func localDirection(weSend bool, peerDirection RTCRtpTransceiverDirection) RTCRt
 }
 
 func (r *RTCPeerConnection) addRTPMediaSection(d *sdp.SessionDescription, codecType RTCRtpCodecType, midValue string, peerDirection RTCRtpTransceiverDirection, candidates []string) {
-
 	media := sdp.NewJSEPMediaDescription(codecType.String(), []string{}).
 		WithValueAttribute(sdp.AttrKeyConnectionSetup, sdp.ConnectionRoleActive.String()). // TODO: Support other connection types
 		WithValueAttribute(sdp.AttrKeyMID, midValue).