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InvalidStateError on websocket object

I'm just starting learning websockets, andI get a strange error:
<script type="text/javascript">
window.onload = function(){
var service = new WebSocket("ws://localhost:8080/websocket/test");
service.onmessage = function(event){
alert("message");
}
service.onopen = function(){
service.send("hello!");
}
service.onclose = function(){
alert("closed");
}
service.onerror = function(){
alert("error");
}
service.send("test");
service.close();
}
</script>
on the line:
service.send("test");
I get:
InvalidStateError: An attempt was made to use an object that is not, or is no longer, usable
Am I missing something important?

The WebSocket.onopen property is an EventHandler that is called when the WebSocket connection's readyState changes to OPEN; this indicates that the connection is ready to send and receive data.
Once you've opened your connection, you can begin transmitting data to the server.
window.onload = function() {
var service = new WebSocket("wss://echo.websocket.org");
service.onmessage = function(event) {
alert("onmessage event: "+event.data);
}
service.onopen = function() {
service.send("test"); //Will work here!
//^^^^^^^^^^^^^^^^^
service.send("hello!");
}
service.onclose = function() {
alert("closed");
}
service.onerror = function() {
alert("error");
}
//Can't close while a connection is still being established.
//service.close();
}

If you use Websocket().send() outside your service.onopen(), you can still check the readyStatebefore sending message, like this:
websocket.sendmessage = async function(msg) {
while (this.readyState === 0) {
await sleep(200);
}
this.send(msg);
};

Windows Store Javascript background audio tassk close() method?

I have created a simple Windows 8.1 store app for just playing internet streaming radio. It looks and works good, but I can't upload my app to Windows Store! After validation a get the message like:
WinJS background task
Error Found:
The WinJS background tasks test encountered the
following errors:
App Radio Skovoroda did not call close() in the
background task JavaScript code found in file default.html.
Impact if not fixed: Apps with background tasks that do not call close() can result in draining the battery.
How to fix: Update the background
task to call close().
The point is I do not need to call close(), because it is a radio player, so, it must play in background for a long time! Any ideas? How to do my app pass the validator?
My script code:
(function () {
"use strict";
var app = WinJS.Application;
var activation = Windows.ApplicationModel.Activation;
app.onactivated = function (args) {
if (args.detail.kind === activation.ActivationKind.launch) {
if (args.detail.previousExecutionState !== activation.ApplicationExecutionState.terminated) {
// TODO: This application has been newly launched. Initialize
// your application here.
} else {
// TODO: This application was suspended and then terminated.
// To create a smooth user experience, restore application state here so that it looks like the app never stopped running.
}
args.setPromise(WinJS.UI.processAll());
var buttonMediaControl = document.getElementById("mediaControlButton");
buttonMediaControl.addEventListener("click", playAndStop, false);
//add variables for social buttons
//Facebook
var fbButton = document.getElementById("fbButton");
fbButton.addEventListener("click", goToFbPage, false);
//VKotakte
var vkButton = document.getElementById("vkButton");
vkButton.addEventListener("click", goToVkPage, false);
//Twitter
var twButton = document.getElementById("twButton");
twButton.addEventListener("click", goToTwPage, false);
//Instagram
var igButton = document.getElementById("igButton");
igButton.addEventListener("click", goToIgPage, false);
//YouTube
var ytButton = document.getElementById("ytButton");
ytButton.addEventListener("click", goToYtPage, false);
//TuneIn
var tiButton = document.getElementById("tiButton");
tiButton.addEventListener("click", goToTiPage, false)
// Assign the button object to MediaControls
var systemMediaControls = Windows.Media.SystemMediaTransportControls.getForCurrentView();
systemMediaControls.addEventListener("buttonpressed", systemMediaControlsButtonPressed, false);
systemMediaControls.isPlayEnabled = true;
systemMediaControls.isPauseEnabled = true;
systemMediaControls.isStopEnabled = true;
systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.closed;
}
};
app.oncheckpoint = function (args) {
};
// Plays the media.
function playMedia() {
var media = document.getElementById("skovorodaStreamingAudio");
media.play();
var statusIcon = document.getElementById("playStopImage");
statusIcon.src = "images/skovoroda_stop_button.png";
var systemMediaControls = Windows.Media.SystemMediaTransportControls.getForCurrentView();
systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.playing;
}
// Pauses the media.
function pauseMedia() {
var media = document.getElementById("skovorodaStreamingAudio");
media.pause();
var statusIcon = document.getElementById("playStopImage");
statusIcon.src = "images/skovoroda_play_button.png";
var systemMediaControls = Windows.Media.SystemMediaTransportControls.getForCurrentView();
systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.paused;
}
// Stops the media.
function stopMedia() {
var media = document.getElementById("skovorodaStreamingAudio");
media.pause();
media.currentTime = 0;
}
function playAndStop() {
var myAudio = document.getElementById("skovorodaStreamingAudio");
var statusIcon = document.getElementById("playStopImage");
if (myAudio.paused) {
var systemMediaControls = Windows.Media.SystemMediaTransportControls.getForCurrentView();
systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.playing;
myAudio.play();
statusIcon.src = "images/skovoroda_stop_button.png";
} else {
var systemMediaControls = Windows.Media.SystemMediaTransportControls.getForCurrentView();
systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.paused;
myAudio.pause();
statusIcon.src = "images/skovoroda_play_button.png";
}
}
// The media Play event handler.
function mediaPlaying() {
// Update the SystemMediaTransportControl state.
systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.playing;
}
// The media Pause event handler.
function mediaPaused() {
// Update the SystemMediaTransportControl state.
systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.paused;
}
// The media Ended event handler.
function mediaEnded() {
// Update the SystemMediaTransportControl state.
systemMediaControls.playbackStatus = Windows.Media.MediaPlaybackStatus.stopped;
}
function goToFbPage() {
window.open("https://www.facebook.com/radioskovoroda?__mref=message_bubble");
}
function goToVkPage() {
window.open("https://vk.com/radioskovoroda");
}
function goToTwPage() {
window.open("https://twitter.com/RadioSkovoroda");
}
function goToIgPage() {
window.open("https://instagram.com/radioskovoroda");
}
function goToYtPage() {
window.open("https://www.youtube.com/channel/UCSgkIdg5MztN_2z9q_8u3Nw")
}
function goToTiPage() {
window.open("http://tunein.com/radio/radio-skovoroda-s248591/")
}
// Event handler for SystemMediaTransportControls' buttonpressed event
function systemMediaControlsButtonPressed() {
if (Windows.Media.MediaControl.isPlaying === true) {
pauseMedia();
} else {
playMedia();
}
}
app.start();
})();

cordova download plugin showing package name on notification bar

I am new to cordova and plugins..
I have created a webappp, in my app i need to download files from server..
so i have used cordova background download plugin.. and i m using intel xdk.. so i have impoted plugin there..
cordova plugin github
now.. when i download file, on notification bar its showing downloading file.. BUT ITS SHOWING PLUGIN PACKAGE NAME WHILE DOWNLOADING.... but file save as its original name.... here it is my code..
var app = {
fileName: "tera hone.mp3",
uriString: "https://api.soundcloud.com/tracks/133667943/stream?client_id=67739332564a7130c3a05f90f2d02d2e", // 38.3 MB
// Application Constructor
initialize: function() {
this.bindEvents();
},
downloadFile: function(uriString, targetFile) {
var lblProgress = document.getElementById('lblProgress');
var complete = function() {
lblProgress.innerHTML = 'Done';
};
var error = function (err) {
console.log('Error: ' + err);
lblProgress.innerHTML = 'Error: ' + err;
};
var progress = function(progress) {
lblProgress.innerHTML = (100 * progress.bytesReceived / progress.totalBytesToReceive) + '%';
};
try{
var downloader = new BackgroundTransfer.BackgroundDownloader();
// Create a new download operation.
var download = downloader.createDownload(uriString, targetFile);
// Start the download and persist the promise to be able to cancel the download.
app.downloadPromise = download.startAsync().then(complete, error, progress);
} catch(err) {
console.log('Error: ' + err);
}
},
// Bind Event Listeners
//
// Bind any events that are required on startup. Common events are:
// 'load', 'deviceready', 'offline', and 'online'.
bindEvents: function() {
document.addEventListener('deviceready', this.onDeviceReady, false);
document.getElementById('btnStart').addEventListener('click', this.startDownload);
document.getElementById('btnStop').addEventListener('click', this.stopDownload);
document.getElementById('btnFileInfo').addEventListener('click', this.getFileInfo);
},
// deviceready Event Handler
//
// The scope of 'this' is the event. In order to call the 'receivedEvent'
// function, we must explicity call 'app.receivedEvent(...);'
onDeviceReady: function() {
app.receivedEvent('deviceready');
app.startDownload();
},
startDownload: function () {
window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function(fileSystem) {
fileSystem.root.getFile(app.fileName, { create: true }, function (newFile) {
app.downloadFile(app.uriString, newFile);
});
});
},
stopDownload: function () {
app.downloadPromise && app.downloadPromise.cancel();
},
getFileInfo: function () {
window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, function (fileSystem) {
fileSystem.root.getFile(app.fileName, { create: true }, function (fileEntry) {
fileEntry.file(function (meta) {
document.getElementById('lblFileInfo').innerHTML =
"Modified: " + meta.lastModifiedDate + "<br/>" +
"size: " + meta.size;
});
}, function(error) {
document.getElementById('lblFileInfo').innerHTML = "error: " + error;
});
});
},
// Update DOM on a Received Event
receivedEvent: function(id) {
var parentElement = document.getElementById(id);
var listeningElement = parentElement.querySelector('.listening');
var receivedElement = parentElement.querySelector('.received');
listeningElement.setAttribute('style', 'display:none;');
receivedElement.setAttribute('style', 'display:block;');
console.log('Received Event: ' + id);
}
};
this is my javascript file invoke from my html file.. from cordova plugin..
also when i stop downloading.. it stops but app suddenly crashed everytime....
sorry for my bad english..

Not able to receive regid from GCM (phonegap app android)

I'm trying to test a Push Notification app with Phonegap. I registered my project at GCM and added my Project Number at the SenderID var. Here's the code:
var app = {
initialize: function() {
this.bindEvents();
},
bindEvents: function() {
document.addEventListener('deviceready', this.onDeviceReady, false);
},
onDeviceReady: function() {
app.receivedEvent('deviceready');
},
receivedEvent: function(id) {
var parentElement = document.getElementById(id);
var listeningElement = parentElement.querySelector('.listening');
var receivedElement = parentElement.querySelector('.received');
listeningElement.setAttribute('style', 'display:none;');
receivedElement.setAttribute('style', 'display:block;');
console.log('Received Event: ' + id);
var pushNotification = window.plugins.pushNotification;
alert("Register called");
pushNotification.register(this.successHandler, this.errorHandler,{"senderID":"543180841340","ecb":"app.onNotificationGCM"});
},
successHandler: function(result) {
alert('Callback Success! Result = '+result)
},
errorHandler:function(error) {
alert(error);
},
onNotificationGCM: function(e) {
switch( e.event )
{
case 'registered':
if ( e.regid.length > 0 )
{
console.log("Regid " + e.regid);
alert('registration id = '+e.regid);
document.getElementById('regId').value = e.regid;
}
break;
case 'message':
alert('message = '+e.message+' msgcnt = '+e.msgcnt);
break;
case 'error':
alert('GCM error = '+e.msg);
break;
default:
alert('An unknown GCM event has occurred');
break;
}
},
onNotificationAPN: function(event) {
var pushNotification = window.plugins.pushNotification;
alert("Running in JS - onNotificationAPN - Received a notification! " + event.alert);
if (event.alert) {
navigator.notification.alert(event.alert);
}
if (event.badge) {
pushNotification.setApplicationIconBadgeNumber(this.successHandler, this.errorHandler, event.badge);
}
if (event.sound) {
var snd = new Media(event.sound);
snd.play();
}
}
};
I get the first alert ("Register called") but not the regID. I'm using the Phonegap Developer app for Android and the "phonegap serve" command to get it live. I tried to download the app too, but still doesn't work.

Firing the ("Register called") Doesn't mean that the push notification registration is instantiated but it means that receivedEvent is called and that is good.
1- Make sure that push notification plugin is included in config.xml and the pushNotification object is not null.
to include the plugin to config.xml: add <gap:plugin name="com.phonegap.plugins.pushplugin" />
2- Make sure that the sender id is OK "no typos".

Broadcasting functions through a service trigger the function multiple times instead of one

I created a service that shares a confirm modal method, and allow to broadcast methods between controillers.
services.SharedService = function($rootScope, $modal) {
var sharedService = {
controller : '',
method : '',
args : []
};
sharedService.prepare = function(controller, method){
this.controller = controller;
this.method = method;
this.broadCast();
};
sharedService.broadCast = function(){
$rootScope.$broadcast('menuBroadcast');
};
return sharedService;
});
Then I have three controllers :
controllers.ctrl1 = function($scope, $rootScope, SharedService) {
$rootScope.$on('menuBroadcast', function() {
if (SharedService.controller == 'ctrl1') {
$scope[SharedService.method]();
}
});
$scope.delete = function(){
var c = window.confirm("Are you sure you want to delete it?");
if(c === true){
//delete
}
};
};
and
controllers.ctrl2 = function($scope, $rootScope, SharedService) {
$rootScope.$on('menuBroadcast', function() {
if (SharedService.controller == 'ctrl1') {
$scope[SharedService.method]();
}
});
$scope.delete = function(){
var c = window.confirm("Are you sure you want to delete it?");
if(c === true){
//delete
}
};
};
};
controllers.menu = function($scope, SharedService) {
$scope.delete1 = function() {
console.debug("Calling delete 1");
SharedService.prepare('ctrl1', 'delete');
};
$scope.delete2 = function() {
console.debug("Calling delete 2");
SharedService.prepare('ctrl2', 'delete');
};
}
The first time I open the confirm from ctrl1, clicking on the ok button works as expected. I can open this modal as many times, it will work.
Then, switching to ctrl2, I open the confirm , I have to click two times on the ok button to be able to close the confirm box.
The console debugs shows that the "calling delete1" and "calling delete2" are triggered only once. But the console.debug from on("menuBroadcast") is triggered sometimes up to 3 times. Any idea why the service triggers the event more than one time? When injected, is it instantiated more than once?

Duplicate of
How can I unregister a broadcast event to rootscope in AngularJS?
The controller is instantiated more than once . I have to un-register the $rootScope.$on listener on when the $destroy is invoked.
var cleanUpFunc = $rootScope.$on('menuBroadcast', function {
if (SharedService.controller == 'ctrl1') {
$scope[SharedService.method]();
}
});
$scope.$on('$destroy', function() {
cleanUpFunc();
});