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JS XHR JSON payload upload progress

Any way to get the progress while uploading a big JSON payload string using XHR?
in my code, it only prints 100% once it is completed, even the json payload size = 30MB
let xmlhttp = new XMLHttpRequest(); // new HttpRequest instance
xmlhttp.addEventListener("progress", function (evt) {
console.log(evt.lengthComputable); // false
if (evt.lengthComputable) {
var percentComplete = evt.loaded / evt.total;
console.log((Math.round(percentComplete * 100) + "%"));
}
}, false);
xmlhttp.onreadystatechange = (event) => {
if (xmlhttp.readyState === 4 && xmlhttp.status >= 200 && xmlhttp.status <= 299) {
let res = JSON.parse(xmlhttp.responseText);
if (typeof this.options.onVideoGetsUploaded === "function") {
console.log('success')
}
} else if (xmlhttp.readyState === 4 && xmlhttp.status >= 400 && xmlhttp.status <= 550) {
//error while uploading
console.log(xmlhttp.statusText)
}
};
xmlhttp.open("POST", this.options.uploadEndPoint, true);
xmlhttp.setRequestHeader("Content-Type", "application/json;charset=UTF-8");
xmlhttp.send(JSON.stringify({
data: base64data
}));

I just went through some old code where I’ve done this. For uploading I did this
var request = new XMLHttpRequest();
// before opening your request
request.upload.onprogress = function(e) {
// progress in % is: Number(e.loaded / e.total * 100)
};
// open and send request
It seems weird and I remember spending some hours trying to figure this one out. Maybe you could also do:
request.upload.addEventListener(“progress”, callback())

You may set content-length header in you request, then the evt.lengthComputable can be true.

Right way to verify that a user is logged

I use AJAX requests to make the user area of my website.
A "Log off" button must be displayed only when the user is connected.
For connecting a user, here my AJAX request:
function requestSI() {
var xhr = getXMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState == 4 && (xhr.status == 200 || xhr.status == 0)) {
document.getElementById("popup_login").innerHTML = "<img src='img/index/cross.png' id='close' onclick ='hidelogin()' /><div id='color2'></div><h2 id=login_title>";
document.getElementById("popup_login").innerHTML += this.responseText;
if (isUserLogged()){
var x = document.getElementById("log_off");
x.classList.remove("inative_logoff");
x.classList.add("active_logoff");
}
}
};
var login_fieldSI = encodeURIComponent(document.getElementById("login_fieldSI").value);
var password_fieldSI = encodeURIComponent(document.getElementById("password_fieldSI").value);
xhr.open("POST", "php/login.php", true);
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xhr.send("Login_fieldSI="+login_fieldSI+"&Password_fieldSI="+password_fieldSI);
}
And here my AJAX request to check if a user is connected:
function isUserLogged(){
var xhr = getXMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState == 4 && (xhr.status == 200 || xhr.status == 0)) {
alert(this.responseText);
if (this.responseText == "true") return true;
else return false;
}
};
xhr.open("POST", "php/is_user_connected.php", true);
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xhr.send(null);
}
My "Log off" button doesn't display for some reason.

function requestSI() {
var xhr = getXMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState == 4 && (xhr.status == 200 || xhr.status == 0)) {
document.getElementById("popup_login").innerHTML = "<img src='img/index/cross.png' id='close' onclick ='hidelogin()' /><div id='color2'></div><h2 id=login_title>";
document.getElementById("popup_login").innerHTML += this.responseText;
isUserLogged();
}
};
var login_fieldSI = encodeURIComponent(document.getElementById("login_fieldSI").value);
var password_fieldSI = encodeURIComponent(document.getElementById("password_fieldSI").value);
xhr.open("POST", "php/login.php", true);
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xhr.send("Login_fieldSI="+login_fieldSI+"&Password_fieldSI="+password_fieldSI);
}
----------
function isUserLogged(){
var xhr = getXMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState == 4 && (xhr.status == 200 || xhr.status == 0)) {
alert(this.responseText);
if (this.responseText == "true"){
alert("ok");
alert("test function");
var x = document.getElementById("log_off");
x.classList.remove("inative_logoff");
x.classList.add("active_logoff");
}
else {
//do your other code..
}
}
};
xhr.open("POST", "php/is_user_connected.php", true);
xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
xhr.send(null);
}

You can try if (isUserLogged() == true){ instead if (isUserLogged()){

Javascript : callback is not a function

I am using vanilla javascript to making AJAX call to my APIs.
Below is my code which i am calling on click of a simple button:
getUserByUserId : function (callback){
var userid = localStorage.getItem('userid');
var userApiUrl = "http://174.129.30.174:8080/users/"+userid;
var xmlhttp = micropaywall.getAjaxInstance();
xmlhttp.onreadystatechange = function()
{
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
var response = JSON.parse(xmlhttp.responseText);
callback(xmlhttp.responseText);
console.log(response);
console.log(xmlhttp.responseText);
}
};
xmlhttp.open("GET", userApiUrl, true);
xmlhttp.send(null);
}
But i get "callback is not a function" at line
callback(xmlhttp.responseText);
Below is my callback function :
getUserByUserIdCallback : function(response){
if(response != "")
{
var res = JSON.parse(response);
var arrAppid = res.appIds;
var userid = res._id;
localStorage.setItem('appid', arrAppid[0]);
var appid = localStorage.getItem('appid');
micropaywall.getUserAccountDetails(userid, appid);
}
}
Please correct me where I am making mistake.

If you don't need to change the "callback" function then you can just call it directly:
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
var response = JSON.parse(xmlhttp.responseText);
getUserByUserIdCallback(xmlhttp.responseText);
console.log(response);
console.log(xmlhttp.responseText);
}
You would only need to pass in a callback function if you want different behavior when calling the getUserByUserId function.

get data from XMLHttprequest

I want to get data in json format.
I have typed this code but it doesn't return anything.
where is the problem in my code?!!
<script language="JavaScript">
var xmlhttp = new XMLHttpRequest();
var url = "http://codeforces.com/api/contest.list?gym=true";
xmlhttp.onreadystatechange = myfunction;
xmlhttp.open("GET", url, true);
xmlhttp.send(null);
function myfunction() {
if (XMLHttp.readyState == 0) {
window.alert("Uninitialized");
}
if (XMLHttp.readyState == 1) {
window.alert("loading");
}
if (XMLHttp.readyState == 2) {
window.alert("loaded");
}
if (XMLHttp.readyState == 3) {
window.alert("waiting");
}
if (XMLHttp.readyState == 4) {
window.alert("completed");
var y = JSON.parse(xmlhttp.responseText);
document.getElementById("id01").innerHTML =y[1].id;
}
}
</script>
in the html code, i have a div with id = "id01"

remember that javascript is case sensitive.
edit it to:
var xmlhttp = new XMLHttpRequest();
var url = "http://codeforces.com/api/contest.list?gym=true";
xmlhttp.onreadystatechange = myfunction;
xmlhttp.open("GET", url, true);
xmlhttp.send(null);
function myfunction() {
if (xmlhttp.readyState == 0) {
window.alert("Uninitialized");
}
if (xmlhttp.readyState == 1) {
window.alert("loading");
}
if (xmlhttp.readyState == 2) {
window.alert("loaded");
}
if (xmlhttp.readyState == 3) {
window.alert("waiting");
}
if (xmlhttp.readyState == 4) {
window.alert("completed");
var y = JSON.parse(xmlhttp.responseText);
document.getElementById("id01").innerHTML =y[1].id;
}
}

try this:
xmlhttp.onload = function() {
if (xmlhttp.status >= 200 && xmlhttp.status < 400) {
// Success!
var data = JSON.parse(xmlhttp.responseText);
} else {
// We reached our target server, but it returned an error
}
};
disclaimer: i took this code from http://youmightnotneedjquery.com/#json

Just use fetch. It is the modern XMLHttpRequest.
const url = "http://codeforces.com/api/contest.list?gym=true";
fetch(url)
.then(
response => response.json() // .text(), etc.
// same as function(response) {return response.json();}
).then(
jsonString => {
const json = JSON.parse(jsonString);
document.getElementById("id01").innerHTML = json[1].id;
}
);
More Info:
Mozilla Documentation
Can I Use (75% Aug 2017)
Matt Walsh Tutorial

Ajax call into httpstatusready=4 doesn't execute

I am using ajax - which works fine - to pass on the value. But when I add the HTTP code, there is no action. Using simple HTTP to show different div values based on http.readystatus. Is this the right format? If not, what is?
if (colorToCheck == gup("Player1")) {
document.getElementById('win').innerHTML = player1 + " wins";
redScore += 1;
//Browser Support Code
var xmlhttp;
if (window.XMLHttpRequest) {
// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp = new XMLHttpRequest();
} else {
// code for IE6, IE5
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
if (xmlhttp.readyState == 3 && xmlhttp.status == 200) {
document.getElementById("save").innerHTML = "saving";
} else if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
//ajax call
var dataString = 'winner=' + player1 + '&player1=' + player1 + '&player2=' + player2 + '&matchNum=' + matchNum;
$.ajax({
type: "POST",
url: "red.php",
data:dataString,
cache: false,
success: function(response) {
$('.result13').html(response);
}
});
}
}
Any help would be highly appreciated! Thanks in advance.

The structure of a Vanilla JS AJAX call is:
var xmlhttp = new XMLHttpRequest();
xmlhttp.open("GET","path/to/file.php"); // or "POST" if needed
xmlhttp.onreadystatechange = function() {
if( this.readyState == 3) document.getElementById('save').innerHTML = "saving";
if( this.readyState == 4) {
if( this.status != 200) alert("ERROR: Server returned "+this.status+" "+this.statusText);
else {
// do something
alert(this.responseText);
}
}
};
xmlhttp.send(data); // data is whatever POST data you want. Leave out if using GET.