index.html

<!DOCTYPE html>
<head>
    <meta charset="utf-8">
    <title>Simple local WebRTC example</title>
</head>
<body>
	<p>Get two chrome clients and open this file on both of them. Let's call the first one A and the second one B. Go to the console on both of them and run some commands.</p>

	<p>On both clients, create a new RTC instance with "var rtc = new RTC();". Then, in client A, run "rtc.init();"</p>

	<p>Copy the spd printed in the console and go to client B. There, paste the sdp in the textbox and make sure it ends with a newline.</p>

	<p>Then run "rtc.connect(textbox.value)". Copy the new sdp you got back and go back to client A again. Paste the new sdp in the textbox here and again make sure it ends with a newline. Then run the command "rtc.answer(textbox.value)".</p>

	<p>Now the connection is established and you can use the "rtc.send(string)" to send messages that will end up in the console on the other client.</p>

	<textarea id="textbox" style="width: 100%; height: 300px"></textarea>

	<script>
		// Creates rtc instance
		function RTC () {
			// Creates rtc connection with data channel
			this.connection = new RTCPeerConnection();
			this.channel = this.connection.createDataChannel("test", {negotiated: true, id: 0});

			// Displays sdp in console when it gets it
			this.connection.onicecandidate = (event) => {
				this.connection.onicecandidate = null;
				console.log(this.connection.localDescription.sdp);
			};

			// Displays messages from the other client in the console
			this.channel.onmessage = (event) => {
				console.log(event.data);
			};
		}

		// Creates new connection
		RTC.prototype.init = function () {
			this.connection.createOffer().then((session) => this.connection.setLocalDescription(session));
		};

		// Connects to a connection on another client
		RTC.prototype.connect = function (sdp) {
			this.connection.setRemoteDescription({type: "offer", sdp: sdp});
			this.connection.createAnswer().then((session) => this.connection.setLocalDescription(session));
		};

		// Answers a connection request from another client
		RTC.prototype.answer = function (sdp) {
			this.connection.setRemoteDescription({type: "answer", sdp: sdp});
		};

		// Sends a string to the other client
		RTC.prototype.send = function (str) {
			this.channel.send(str);
		};
	</script>
</body>
</html>