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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);
});

Problems converting JavaScript to GopherJs

I am trying to convert this whole section of code from Javascript to GopherJs.
So far i have not been able to do event listeners as i am still a newbie to Javascript.
This is the JavaScript
window.addEventListener("load", function(evt) {
var output = document.getElementById("output");
var input = document.getElementById("input");
var ws;
var print = function(message) {
var d = document.createElement("div");
d.innerHTML = message;
output.appendChild(d);
};
document.getElementById("open").onclick = function(evt) {
if (ws) {
return false;
}
ws = new WebSocket("{{.}}");
ws.onopen = function(evt) {
print("OPEN");
}
ws.onclose = function(evt) {
print("CLOSE");
ws = null;
}
ws.onmessage = function(evt) {
print("RESPONSE: " + evt.data);
}
ws.onerror = function(evt) {
print("ERROR: " + evt.data);
}
return false;
};
document.getElementById("send").onclick = function(evt) {
if (!ws) {
return false;
}
print("SEND: " + input.value);
ws.send(input.value);
return false;
};
document.getElementById("close").onclick = function(evt) {
if (!ws) {
return false;
}
ws.close();
return false;
};
});
I have gone through a few iterations of attempts but it is still not working.
Below is a snippet of my last attempt.
var ws *websocketjs.WebSocket
var err error
//js.Global.Get("document").Call("write", "Hello world!")
js.Global.Call("addEventListener", "load", func(ev *js.Object) {
//js.Global.Get("document").Get("open") = func(ev *js.Object){
onOpen := func(ev *js.Object) {
if ws == nil {
ws, err = websocketjs.New("ws://localhost:8000/ws") // Does not block.
if err != nil {
println(err)
}
}
fmt.Println("we are past the ws part")
js.Global.Get("document").Call("write", "It is opened!")
/////////////////////////////////////////////////
err = ws.Send("Hello Websockets!") // Send a text frame.
if err != nil {
fmt.Println(err)
}
println("it is open now")
}
ws.AddEventListener("open", false, onOpen)
//}
})
//ws.AddEventListener("open", false, onOpen)
//ws.AddEventListener("message", false, onMessage)
//ws.AddEventListener("close", false, onClose)
//ws.AddEventListener("error", false, onError)
err = ws.Close()
I would atleast like to see the first 2 parts done correctly. I can finish the rest with a good example.
Thanks

To obtain the DOM i used "honnef.co/go/js/dom" library.
Everything else was step by step as in Javascript.
Example:
package main
import "honnef.co/go/js/dom"
func main() {
d := dom.GetWindow().Document()
h := d.GetElementByID("foo")
h.SetInnerHTML("Hello World")
}

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.

Uncaught TypeError: Cannot call method 'transaction' of undefined when using indexedDB

I have the following code for getting records from indexeddb on chrome 30.
var IndexedDBStorage = function (name) {
// until we won't need this prefix mess
var indexedDB = window.indexedDB || window.webkitIndexedDB
|| window.mozIndexedDB || window.msIndexedDB;
var IDBTransaction = window.IDBTransaction ||
window.webkitIDBTransaction;
var db;
// The initialization of our stuff
this.Supported = function () {
return indexedDB;
};
this.type = function () {
return "IndexedDB";
};
this.Setup = function () {
var dbVersion = 1.0;
var openRequest = indexedDB.open(name, dbVersion);
//handle setup - as the spec like it
openRequest.onupgradeneeded = function (e) {
console.log("running onupgradeneeded");
var thisDb = e.target.result;
if (!thisDb.objectStoreNames.contains(name)) {
var objectStore = thisDb.createObjectStore(name, {
autoIncrement: false
});
objectStore.createIndex("dataKey", "dataKey",
{ unique: false });
}
};
openRequest.onsuccess = function (e) {
db = e.target.result;
db.onerror = function (event) {
alert("Database error: " + event.target.errorCode);
console.dir(event.target);
};
if (db.setVersion) {
console.log("in old setVersion: " + db.setVersion);
if (db.version != dbVersion) {
var req = db.setVersion(dbVersion);
req.onsuccess = function () {
var ob = db.createObjectStore(name, {
autoIncrement: false
});
ob.createIndex("datakey",
"datakey", { unique: false });
var trans = req.result;
trans.oncomplete = function (ex) {
console.log("== trans oncomplete ==");
};
};
}
}
console.log(db);
};
};
this.GetAll = function (callback) {
console.log(db);
var transaction = db.transaction([name]); <-- gives error described below
var store = transaction.objectStore(name);
var items = [];
transaction.oncomplete = function (evt) {
callback(items);
};
var cursorRequest = store.openCursor();
cursorRequest.onerror = function (error) {
console.log(error);
};
cursorRequest.onsuccess = function (evt) {
var cursor = evt.target.result;
if (cursor) {
items.push({ key: cursor.key, body: cursor.value.body });
cursor.continue();
}
};
};
};
if i call it from a button like this :
it works fine if i do like this and call it from a button click, it works just fine:
function Init() { <-- called from script tag in index.html
$(document).ready(function () {
window.dataStore = new Store("data");
});
}
function getAll() { <-- button lick function
window.dataStore.getAll();
}
however, if i call it directly after initialization like this
function Init() {
$(document).ready(function () {
window.dataStore = new Store("data");
window.dataStore.GetAll();
});
}
i get a error with
Uncaught TypeError: Cannot call method 'transaction' of undefined
i am guessing it is because the db variable has not yet been globally set from openRequest.onsuccess when i call directly after init.
How can i fix this so it gets set properly

This is due the async behavior of the indexedDB API.
The db variable isn't assigned yet because the onsucces isn't called yet. To solve this you will have to provide a callback when the onsuccess is called on the openrequest, or you will have to delay the execution of the getAll call as long if the db variable is undefined.

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;
}
}
}
}