Enclose server message handling.

client/peer-exchange.js

@@ -13,7 +13,7 @@ export function createPeerExchange(address) {
             return;
         }
 
-        listeners.forEach(callback => callback(data));
+        listeners.forEach(callback => callback(data, send));
     }
 
     function listen(callback) {

client/peer.js

@@ -4,6 +4,26 @@ function errorHandler(error) {
 
 export function createPeer(peerExchange, peerConnectionConfig) {
     const conn = new RTCPeerConnection(peerConnectionConfig);
+    peerExchange.listen(createPeerExchangeMessageHandler(conn));
 
     return conn;
 }
+
+function createPeerExchangeMessageHandler(conn) {
+    return function gotMessageFromServer(signal, send) {
+        if(signal.sdp) {
+            conn.setRemoteDescription(new RTCSessionDescription(signal.sdp)).then(function() {
+                // Only create answers in response to offers
+                if(signal.sdp.type == 'offer') {
+                    conn.createAnswer()
+                    .then(desc => {
+                        conn.setLocalDescription(desc);
+                        send({'sdp': desc})
+                    }).catch(errorHandler);
+                }
+            }).catch(errorHandler);
+        } else if(signal.ice) {
+            conn.addIceCandidate(new RTCIceCandidate(signal.ice)).catch(errorHandler);
+        }
+    };
+}

client/webrtc.js

@@ -17,7 +17,6 @@ function pageReady() {
     remoteVideo = document.getElementById('remoteVideo');
 
     serverConnection = createPeerExchange('wss://' + window.location.hostname + ':8443');
-    serverConnection.listen(gotMessageFromServer);
 
     setup();
 }
@@ -28,7 +27,7 @@ function getUserMediaSuccess(stream) {
 }
 
 function setup() {
-    peerConnection = createPeer(null, peerConnectionConfig);
+    peerConnection = createPeer(serverConnection, peerConnectionConfig);
 
     peerConnection.addEventListener('icecandidate', gotIceCandidate);
     peerConnection.addEventListener('addstream', gotRemoteStream);
@@ -75,19 +74,6 @@ function extendOffer() {
     peerConnection.createOffer().then(createdDescription).catch(errorHandler);
 }
 
-function gotMessageFromServer(signal) {
-    if(signal.sdp) {
-        peerConnection.setRemoteDescription(new RTCSessionDescription(signal.sdp)).then(function() {
-            // Only create answers in response to offers
-            if(signal.sdp.type == 'offer') {
-                peerConnection.createAnswer().then(createdDescription).catch(errorHandler);
-            }
-        }).catch(errorHandler);
-    } else if(signal.ice) {
-        peerConnection.addIceCandidate(new RTCIceCandidate(signal.ice)).catch(errorHandler);
-    }
-}
-
 function gotIceCandidate(event) {
     if(event.candidate != null) {
         serverConnection.send({'ice': event.candidate});