Add error events

Readme.md

@@ -33,6 +33,7 @@ gclient.connect("ws://localhost:8001/gaze");
 |---|---|---|---|
 | ConnectionOpenedEvent  | connectionclosed  | Invoked when client successfully connected to server.  | - |
 | ConnectionClosedEvent  | connectionclosed  | Invoked when client lost connection to server. | - |
+| ConnectionErrorEvent  | erroroccurred  | Invoked when an error occurred during server client communication. | - |
 | DataEvent | dataavailable  | Invoked when new gaze data from eye-tracker is available.  | On-display (x,y) coordinates for both eyes |
 
 ## Build

lib/com/Events.js

@@ -25,4 +25,10 @@ class ConnectionClosedEvent extends Event {
   }
 }
 
-export {DataEvent, ConnectionOpenedEvent, ConnectionClosedEvent};
\ No newline at end of file
+class ConnectionErrorEvent extends Event {
+  constructor() {
+    super("erroroccurred");
+  }
+}
+
+export {DataEvent, ConnectionOpenedEvent, ConnectionClosedEvent, ConnectionErrorEvent};
\ No newline at end of file

lib/com/WebSocketClient.js

 import Observable from "../utils/Observable.js";
-import { ConnectionOpenedEvent, DataEvent } from "./Events.js";
+import { ConnectionOpenedEvent, ConnectionClosedEvent, ConnectionErrorEvent, DataEvent } from "./Events.js";
 
 class WebSocketClient extends Observable {
 
@@ -10,6 +10,8 @@ class WebSocketClient extends Observable {
   connect(url) {
     this.ws = new WebSocket(url);
     this.ws.onopen = onOpen.bind(this);
+    this.ws.onclose = onClose.bind(this);
+    this.ws.onerror = onError.bind(this);
     this.ws.onmessage = onMessage.bind(this);
   }
 
@@ -20,6 +22,16 @@ function onOpen() {
   this.notifyAll(connectionEvent);
 }
 
+function onClose() {
+  let connectionEvent = new ConnectionClosedEvent();
+  this.notifyAll(connectionEvent);
+}
+
+function onError() {
+  let connectionEvent = new ConnectionErrorEvent();
+  this.notifyAll(connectionEvent);
+}
+
 function onMessage(event) {
   let dataEvent = new DataEvent(event.data);
   this.notifyAll(dataEvent);

lib/index.js

@@ -12,6 +12,7 @@ class GazeClient extends Observable {
     this.client = new WebSocketClient();
     this.client.addEventListener("connectionopened", this.onConnected.bind(this));
     this.client.addEventListener("connectionclosed", this.onDisconnected.bind(this));
+    this.client.addEventListener("erroroccurred", this.onDisconnected.bind(this));
     this.client.addEventListener("dataAvailable", this.onDataAvailable
       .bind(this));
     this.client.connect(url);
@@ -25,6 +26,10 @@ class GazeClient extends Observable {
     this.notifyAll(event);
   }
 
+  onError(event) {
+    this.notifyAll(event);
+  }
+
   onDataAvailable(event) {
     this.notifyAll(event);
   }