Add data-channels jsfiddle to git

examples/data-channels/jsfiddle/demo.js

@@ -0,0 +1,41 @@
+/* eslint-env browser */
+
+let pc = new RTCPeerConnection()
+let log = msg => {
+  document.getElementById('logs').innerHTML += msg + '<br>'
+}
+
+let sendChannel = pc.createDataChannel('foo')
+sendChannel.onclose = () => console.log('sendChannel has closed')
+sendChannel.onopen = () => console.log('sendChannel has opened')
+sendChannel.onmessage = e => console.log(`sendChannel got ${e.data}`)
+
+pc.oniceconnectionstatechange = e => log(pc.iceConnectionState)
+
+pc.onnegotiationneeded = e =>
+  pc.createOffer({ }).then(d => {
+    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)
+}
+
+window.startSession = () => {
+  let sd = document.getElementById('remoteSessionDescription').value
+  if (sd === '') {
+    return alert('Session Description must not be empty')
+  }
+
+  try {
+    pc.setRemoteDescription(new RTCSessionDescription({type: 'answer', sdp: atob(sd)}))
+  } catch (e) {
+    alert(e)
+  }
+}