We Keep Coding

Ping site with knockout.js

I want to ping a few sites using javascript, and found this pen and does what I want.
However, I don't understand when I add goo12121212gle.com to the list of sites as a test it comes up saying that the domain has responded but in the console log I see ERR_NAME_NOT_RESOLVED??
I am new to JS but I am not sure why the below script is both saying the site is there and not at the same time? Is something missing from the script?
function ping(ip, callback) {
if (!this.inUse) {
this.status = 'unchecked';
this.inUse = true;
this.callback = callback;
this.ip = ip;
var _that = this;
this.img = new Image();
this.img.onload = function () {
_that.inUse = false;
_that.callback('online');
};
this.img.onerror = function (e) {
if (_that.inUse) {
_that.inUse = false;
_that.callback('offline', e);
}
};
this.start = new Date().getTime();
this.img.src = "http://" + ip;
this.timer = setTimeout(function () {
if (_that.inUse) {
_that.inUse = false;
_that.callback('timeout');
}
}, 1500);
}
}
var PingModel = function (servers) {
var self = this;
var myServers = [];
ko.utils.arrayForEach(servers, function (location) {
myServers.push({
name: location,
status: ko.observable('unchecked')
});
});
self.servers = ko.observableArray(myServers);
ko.utils.arrayForEach(self.servers(), function (s) {
s.status('checking');
new ping(s.name, function (status, e) {
s.status(e ? "error" : status);
});
});
};
var komodel = new PingModel(['goo12121212gle.com','msn.com','104.46.36.174','23.97.201.12']);
ko.applyBindings(komodel);
https://codepen.io/lyellick0506/pen/NGJgry

Both the onerror- and onload-callback use "responded" as the message, so there is no way to differentiate between them:
this.img.onerror = function (e) {
if (_that.inUse) {
_that.inUse = false;
_that.callback('responded', e); // <--- change this to a different message
}
};
Alternatively you could just check if the e parameter has been set:
new ping(s.name, function (status, e) {
s.status(e ? "error" : status);
});

Nested function not work in Mozilla browser

i have call the below function in my application
function workerCall() {
debugger;
if (typeof (Worker) !== "undefined") {
var worker = new Worker("Scripts/worker.js");
worker.onmessage = workerResultReceiver;
worker.onerror = workerErrorReceiver;
worker.postMessage({ 'username': Username });
function workerResultReceiver(e) {
$('.NotificationCount').html(e.data);
if (parseInt(e.data) != 0 && currentPage == "Alert") {
StateFlag = false;
$('.Notification').show();
$('.Drildown').each(function () {
var temp = this.id;
if ($('#' + temp).attr('expand') == "true") {
currentTab = temp;
StateFlag = true;
}
});
currentScrollPosition = $('body').scrollTop();
GetAlerts();
} else {
$('.Notification').hide();
}
}
function workerErrorReceiver(e) {
console.log("there was a problem with the WebWorker within " + e);
}
}
else {
}
}
the method will execute in IE,Chrome but when comes to Mozilla i got an error ReferenceError: workerResultReceiver is not defined.How can i resolve this error?

This happens because you are making reference to function that is not created yet. You need to put this:
worker.onmessage = workerResultReceiver;
worker.onerror = workerErrorReceiver;
Above
function workerErrorReceiver
line or at the end of the scope.

Why is indexedDB is giving an invalid state error?

when I run this code:
var idbSupported = false;
var db;
document.addEventListener("DOMContentLoaded", function(){
if("indexedDB" in window) {
idbSupported = true;
}
if(idbSupported) {
var openRequest = indexedDB.open("test",1);
openRequest.onupgradeneeded = function(e) {
console.log("Upgrading...");
}
openRequest.onsuccess = function(e) {
console.log("Success!");
db = e.target.result;
}
openRequest.onerror = function(e) {
console.log("Error: " + e.target.errorCode);
// console.dir(e);
}
}
},false);
from this tutorial:
http://net.tutsplus.com/tutorials/javascript-ajax/working-with-indexeddb/
in Firefox 17.
Don't know why I'm getting the error event instead of the success event.
Simplified code gives the same error: ( Just copy-paste ) this into your console see.
(function(){
if(window.indexedDB) {
var openRequest = indexedDB.open("test", 1);
openRequest.onupgradeneeded = function(e) {
console.log("Upgrading...");
}
openRequest.onsuccess = function(e) {
console.log("Success!");
db = e.target.result;
}
openRequest.onerror = function(e) {
console.log("Error: " + e.target.errorCode);
console.dir(e);
}
}
})();
According to here, FF 16 and up do not need a prefix.
One thing I noted, is that the browser is not asking for permission to use indexedDB as it should so maybe the browser is not configured to use indexedDB?

HTML5 Websocket within Webworker

I've managed to get websockets working inside a webworker using Chrome, but only for receiving data. When I try to send data I get a DOM Exception, has anyone managed to send data?
This is what I have for my web worker.
self.addEventListener('message', function(e) {
var data = e.data;
switch (data.cmd) {
case 'init':
self.postMessage("Initialising Web Workers...");
testWS();
break;
default:
self.postMessage('Unknown command: ' + data.msg);
};
}, false);
function testWS() {
var connectionAddr = "ws://localhost:8003";
var socket = new WebSocket(connectionAddr);
socket.onmessage = function(event) {
self.postMessage('Websocket : ' + event.data);
};
socket.onclose = function(event) {
};
function send(message) {
socket.send(message);
}
send("hello"); //Here is where the exception is thrown
}

You must listen for the onopen websocket event before sending your first message.
socket.onopen = function(){
// send some message
};

Try this:
var WebSocketStateEnum = {CONNECTING: 0, OPEN: 1, CLOSING: 2, CLOSED: 3};
var wsChannel;
var msgQueue = [];
// Using like this:
sendMessage(_ => {
wsChannel.send('message...'); // This will wait until the connection open, unless it is already opened
});
function sendMessage(task) {
if (!wsChannel || wsChannel.readyState != WebSocketStateEnum.OPEN) {
msgQueue.push(task);
} else {
task();
}
if (!wsChannel) {
wsChannel = new WebSocket('ws://your-url');
wsChannel.onopen = function() {
while (msgQueue.length > 0) {
msgQueue.shift()();
}
}
wsChannel.onmessage = function(evt) {
// message received here
}
wsChannel.onclose = function(evt) {
wsChannel = null;
}
wsChannel.onerror = function(evt) {
if (wsChannel.readyState == WebSocketStateEnum.OPEN) {
wsChannel.close();
} else {
wsChannel = null;
}
}
}
}

PDF.js pages does not get painted. Only white pages are displayed

I am trying to render a pdf in chrome using PDFJS
This is the function I am calling:
open: function pdfViewOpen(url, scale, password) {
var parameters = {password: password};
if (typeof url === 'string') { // URL
this.setTitleUsingUrl(url);
parameters.url = url;
} else if (url && 'byteLength' in url) { // ArrayBuffer
parameters.data = url;
}
if (!PDFView.loadingBar) {
PDFView.loadingBar = new ProgressBar('#loadingBar', {});
}
this.pdfDocument = null;
var self = this;
self.loading = true;
getDocument(parameters).then(
function getDocumentCallback(pdfDocument) {
self.load(pdfDocument, scale);
self.loading = false;
},
function getDocumentError(message, exception) {
if (exception && exception.name === 'PasswordException') {
if (exception.code === 'needpassword') {
var promptString = mozL10n.get('request_password', null,
'PDF is protected by a password:');
password = prompt(promptString);
if (password && password.length > 0) {
return PDFView.open(url, scale, password);
}
}
}
var loadingErrorMessage = mozL10n.get('loading_error', null,
'An error occurred while loading the PDF.');
if (exception && exception.name === 'InvalidPDFException') {
// change error message also for other builds
var loadingErrorMessage = mozL10n.get('invalid_file_error', null,
'Invalid or corrupted PDF file.');
//#if B2G
// window.alert(loadingErrorMessage);
// return window.close();
//#endif
}
var loadingIndicator = document.getElementById('loading');
loadingIndicator.textContent = mozL10n.get('loading_error_indicator',
null, 'Error');
var moreInfo = {
message: message
};
self.error(loadingErrorMessage, moreInfo);
self.loading = false;
},
function getDocumentProgress(progressData) {
self.progress(progressData.loaded / progressData.total);
}
);
}
This is the call:
PDFView.open('/MyPDFs/Pdf2.pdf', 'auto', null);
All I get is this:
If you notice, even the page number is retrieved but the content is not painted in the pages. Can´t find why.. Is the any other function I should call next to PDFView.open?

Found the solution...!
This is the code that does the work.
$(document).ready(function () {
PDFView.initialize();
var params = PDFView.parseQueryString(document.location.search.substring(1));
//#if !(FIREFOX || MOZCENTRAL)
var file = params.file || DEFAULT_URL;
//#else
//var file = window.location.toString()
//#endif
//#if !(FIREFOX || MOZCENTRAL)
if (!window.File || !window.FileReader || !window.FileList || !window.Blob) {
document.getElementById('openFile').setAttribute('hidden', 'true');
} else {
document.getElementById('fileInput').value = null;
}
//#else
//document.getElementById('openFile').setAttribute('hidden', 'true');
//#endif
// Special debugging flags in the hash section of the URL.
var hash = document.location.hash.substring(1);
var hashParams = PDFView.parseQueryString(hash);
if ('disableWorker' in hashParams)
PDFJS.disableWorker = (hashParams['disableWorker'] === 'true');
//#if !(FIREFOX || MOZCENTRAL)
var locale = navigator.language;
if ('locale' in hashParams)
locale = hashParams['locale'];
mozL10n.setLanguage(locale);
//#endif
if ('textLayer' in hashParams) {
switch (hashParams['textLayer']) {
case 'off':
PDFJS.disableTextLayer = true;
break;
case 'visible':
case 'shadow':
case 'hover':
var viewer = document.getElementById('viewer');
viewer.classList.add('textLayer-' + hashParams['textLayer']);
break;
}
}
//#if !(FIREFOX || MOZCENTRAL)
if ('pdfBug' in hashParams) {
//#else
//if ('pdfBug' in hashParams && FirefoxCom.requestSync('pdfBugEnabled')) {
//#endif
PDFJS.pdfBug = true;
var pdfBug = hashParams['pdfBug'];
var enabled = pdfBug.split(',');
PDFBug.enable(enabled);
PDFBug.init();
}
if (!PDFView.supportsPrinting) {
document.getElementById('print').classList.add('hidden');
}
if (!PDFView.supportsFullscreen) {
document.getElementById('fullscreen').classList.add('hidden');
}
if (PDFView.supportsIntegratedFind) {
document.querySelector('#viewFind').classList.add('hidden');
}
// Listen for warnings to trigger the fallback UI. Errors should be caught
// and call PDFView.error() so we don't need to listen for those.
PDFJS.LogManager.addLogger({
warn: function () {
PDFView.fallback();
}
});
var mainContainer = document.getElementById('mainContainer');
var outerContainer = document.getElementById('outerContainer');
mainContainer.addEventListener('transitionend', function (e) {
if (e.target == mainContainer) {
var event = document.createEvent('UIEvents');
event.initUIEvent('resize', false, false, window, 0);
window.dispatchEvent(event);
outerContainer.classList.remove('sidebarMoving');
}
}, true);
document.getElementById('sidebarToggle').addEventListener('click',
function () {
this.classList.toggle('toggled');
outerContainer.classList.add('sidebarMoving');
outerContainer.classList.toggle('sidebarOpen');
PDFView.sidebarOpen = outerContainer.classList.contains('sidebarOpen');
PDFView.renderHighestPriority();
});
document.getElementById('viewThumbnail').addEventListener('click',
function () {
PDFView.switchSidebarView('thumbs');
});
document.getElementById('viewOutline').addEventListener('click',
function () {
PDFView.switchSidebarView('outline');
});
document.getElementById('previous').addEventListener('click',
function () {
PDFView.page--;
});
document.getElementById('next').addEventListener('click',
function () {
PDFView.page++;
});
document.querySelector('.zoomIn').addEventListener('click',
function () {
PDFView.zoomIn();
});
document.querySelector('.zoomOut').addEventListener('click',
function () {
PDFView.zoomOut();
});
document.getElementById('fullscreen').addEventListener('click',
function () {
PDFView.fullscreen();
});
document.getElementById('openFile').addEventListener('click',
function () {
document.getElementById('fileInput').click();
});
document.getElementById('print').addEventListener('click',
function () {
window.print();
});
document.getElementById('download').addEventListener('click',
function () {
PDFView.download();
});
document.getElementById('pageNumber').addEventListener('change',
function () {
PDFView.page = this.value;
});
document.getElementById('scaleSelect').addEventListener('change',
function () {
PDFView.parseScale(this.value);
});
document.getElementById('first_page').addEventListener('click',
function () {
PDFView.page = 1;
});
document.getElementById('last_page').addEventListener('click',
function () {
PDFView.page = PDFView.pdfDocument.numPages;
});
document.getElementById('page_rotate_ccw').addEventListener('click',
function () {
PDFView.rotatePages(-90);
});
document.getElementById('page_rotate_cw').addEventListener('click',
function () {
PDFView.rotatePages(90);
});
//#if (FIREFOX || MOZCENTRAL)
//if (FirefoxCom.requestSync('getLoadingType') == 'passive') {
// PDFView.setTitleUsingUrl(file);
// PDFView.initPassiveLoading();
// return;
//}
//#endif
//#if !B2G
PDFView.open(file, 0);
//#endif
});
The system must be initialized first before PDFView.open call!
Thanks