app.js

(function(document) {
  'use strict';
  // Initialise DataChannel.js
  var datachannel = new DataChannel();

  // Set the userid based on what has been defined by DataChannel
  // https://github.com/muaz-khan/WebRTC-Experiment/tree/master/DataChannel#use-custom-user-ids
  datachannel.userid = window.userid;

  // Open a connection to Pusher
  var pusher = new Pusher("df35e5b0764ce9459acb");

  // Storage of Pusher connection socket ID
  var socketId;

  Pusher.log = function(message) {
    if (window.console && window.console.log) {
      window.console.log(message);
    }
  };

  // Monitor Pusher connection state
  pusher.connection.bind("state_change", function(states) {
    switch (states.current) {
      case "connected":
        socketId = pusher.connection.socket_id;
        break;
      case "disconnected":
      case "failed":
      case "unavailable":
        break;
    }
  });

  // Set custom Pusher signalling channel
  // https://github.com/muaz-khan/WebRTC-Experiment/blob/master/Signaling.md
  datachannel.openSignalingChannel = function(config) {
    var channel = config.channel || this.channel || "default-channel";
    var xhrErrorCount = 0;
    
    var socket = {
      send: function(message) {
        $.ajax({
          type: "POST",
          url: "/message", // Node.js & Ruby (Sinatra)
          // url: "_servers/php/message.php", // PHP
          data: {
            socketId: socketId,
            channel: channel,
            message: message
          },
          timeout: 1000,
          success: function(data) {
            xhrErrorCount = 0;
          },
          error: function(xhr, type) {
            // Increase XHR error count
            xhrErrorCount++;

            // Stop sending signaller messages if it's down
            if (xhrErrorCount > 5) {
              console.log("Disabling signaller due to connection failure");
              datachannel.transmitRoomOnce = true;
            }
          }
        });
      },
      channel: channel
    };

    // Subscribe to Pusher signalling channel
    var pusherChannel = pusher.subscribe(channel);

    // Call callback on successful connection to Pusher signalling channel
    pusherChannel.bind("pusher:subscription_succeeded", function() {
      if (config.callback) config.callback(socket);
    });

    // Proxy Pusher signaller messages to DataChannel
    pusherChannel.bind("message", function(message) {
      config.onmessage(message);
    });

    return socket;
  };

  var onCreateChannel = function() {
    var channelName = cleanChannelName(channelInput.value);

    if (!channelName) {
      console.log("No channel name given");
      return;
    }

    disableConnectInput();

    datachannel.open(channelName);
  };

  var onJoinChannel = function() {
    var channelName = cleanChannelName(channelInput.value);

    if (!channelName) {
      console.log("No channel name given");
      return;
    }

    disableConnectInput();

    // Search for existing data channels
    datachannel.connect(channelName);
  };

  var cleanChannelName = function(channel) {
    return channel.replace(/(\W)+/g, "-").toLowerCase();
  };

  var onSendMessage = function() {
    var message = messageInput.value;

    if (!message) {
      console.log("No message given");
      return;
    }

    datachannel.send(message);
    addMessage(message, window.userid, true);

    messageInput.value = "";  
  };

  var onMessageKeyDown = function(event) {
    if (event.keyCode == 13){
      onSendMessage();
    }
  };

  var addMessage = function(message, userId, self) {
    var messages = messageList.getElementsByClassName("list-group-item");

    // Check for any messages that need to be removed
    var messageCount = messages.length;
    for (var i = 0; i < messageCount; i++) {
      var msg = messages[i];
      
      if (msg.dataset.remove === "true") {
        messageList.removeChild(msg);
      }
    };

    var newMessage = document.createElement("li");
    newMessage.classList.add("list-group-item");

    if (self) {
      newMessage.classList.add("self");
      newMessage.innerHTML = "<span class='badge'>You</span><p>" + message + "</p>";
    } else {
      newMessage.innerHTML = "<span class='badge'>" + userId + "</span><p>" + message + "</p>"
    }

    messageList.appendChild(newMessage);
  };

  var disableConnectInput = function() {
    channelInput.disabled = true;
    createChannelBtn.disabled = true;
    joinChannelBtn.disabled = true;
  };

  // Demo DOM elements
  var channelInput = document.querySelector(".demo-chat-channel-input");
  var createChannelBtn = document.querySelector(".demo-chat-create");
  var joinChannelBtn = document.querySelector(".demo-chat-join");
  var messageInput = document.querySelector(".demo-chat-message-input");
  var sendBtn = document.querySelector(".demo-chat-send");
  var messageList = document.querySelector(".demo-chat-messages");

  // Set up DOM listeners
  createChannelBtn.addEventListener("click", onCreateChannel);
  joinChannelBtn.addEventListener("click", onJoinChannel);
  sendBtn.addEventListener("click", onSendMessage);
  messageInput.addEventListener("keydown", onMessageKeyDown);

  // Set up DataChannel handlers
  datachannel.onopen = function (userId) {
    document.querySelector(".demo-connect").classList.add("inactive");
    document.querySelector(".demo-chat").classList.remove("inactive");
    messageInput.focus();
  };

  datachannel.onmessage = function (message, userId) {
    addMessage(message, userId);
  };

})(document);

server.go

package hello

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"

	"github.com/pusher/pusher-http-go"
)

var client pusher.Client

// init is run before the application starts serving.
func init() {
	client = pusher.Client{
		AppId:  "131030",
		Key:    "df35e5b0764ce9459acb",
		Secret: "a5f315edaab967e024ed",
	}

	// Handle all requests with path /hello with the helloHandler function.

	// http.HandleFunc("/pusher/auth", pusherAuth)

	http.HandleFunc("/message", messageHandler)
}

func messageHandler(w http.ResponseWriter, r *http.Request) {
	params, _ := ioutil.ReadAll(r.Body)
	u, _ := url.Parse(string(params))
	m, _ := url.ParseQuery(u.String())

	client.TriggerExclusive(m["channel"][0], "message", map[string]string{"roomToken": m["message[roomToken]"][0], "broadcaster": m["message[broadcaster]"][0]}, m["socketId"][0])

	fmt.Fprint(w, nil)
}

Hi - it's Jamie here from Pusher (who wrote the Go library). Is this on Google App Engine?

If so - see here: https://github.com/pusher/pusher-http-go#google-app-engine

Are there any error logs?

Hi Jamie - thanks for getting in touch with me. Yeah I figured out it was the GAE stuff - wasn't using the urlfetch. I think you guys wrote this go lib. Either way once I included all the GAE related stuff, everything began working as expected. Thanks for the quick reply - sorry I didn't see your comments until now. I need to hook up gist notifications or something.

Thanks again!

-Zach