Develop Reference

How to use setTimeout without using setTimeout function

Is there a way to use setTimeout without using setTimeout inbuilt function?
I don't want to use setInterval or clearInterval either or window.use. I have gone through multiple blogs, but all those use window, setInterval or clearInterval.
For example, the below code works, but I dont want to have window.
const setTimeouts = [];
function customSetTimeout(cb, interval) {
const now = window.performance.now();
const index = setTimeouts.length;
setTimeouts[index] = () => {
cb();
};
setTimeouts[index].active = true;
const handleMessage = (evt) => {
if (evt.data === index) {
if (window.performance.now() - now >= interval) {
window.removeEventListener('message', handleMessage);
if (setTimeouts[index].active) {
setTimeouts[index]();
}
} else {
window.postMessage(index, '*');
}
}
};
window.addEventListener('message', handleMessage);
window.postMessage(index, '*');
return index;
}
const setIntervals = [];
function customSetInterval(cb, interval) {
const intervalId = setIntervals.length;
setIntervals[intervalId] = function () {
if (setIntervals[intervalId].active) {
cb();
customSetTimeout(setIntervals[intervalId], interval);
}
};
setIntervals[intervalId].active = true;
customSetTimeout(setIntervals[intervalId], interval);
return intervalId;
}
function customClearInterval(intervalId) {
if (setIntervals[intervalId]) {
setIntervals[intervalId].active = false;
}
}
console.log("1");
customSetTimeout(function() {
console.log('3s');
}, 3000);
console.log("2");
=======================================
Alternate solution:
But here, again i dont want to use clearInterval and setInterval
var setMyTimeOut = function(foo,timeOut){
console.log('inside time out');
var timer;
var currentTime = new Date().getTime();
var blah=()=>{
if (new Date().getTime() >= currentTime + timeOut) {
console.log('clear interval if');
clearInterval(timer);
foo()
}
console.log('clear interval else');
}
timer= setInterval(blah, 100);
}
console.log("1");
setMyTimeOut(function() {
console.log('3s');
}, 3000);
console.log("2");
Is there way to achieve the same but without the use setInterval and clearInterval?

I use here the requestAnimationFrame with performance.now().
Its not super exact (well setTimeout neither), but it do the work.
function sleep(delay, cb) {
function check(time, delay) {
if(time >= delay) {
cb("done");
return;
}
time = performance.now();
requestAnimationFrame(check.bind(null, time,delay))
}
check(performance.now(), delay + performance.now());
}
sleep(4000, ()=> {
console.log("sleep done");
})
console.log("i do not block the main thread");

You can use a while loop which checks a set time against the current time:
const startTime = new Date().getTime() + 3000;
let currentTime = new Date().getTime();
function customTimeout() {
while (startTime > currentTime) {
currentTime = new Date().getTime();
}
return console.log('3 Seconds')
};
customTimeout();

How to decrement given time

I am getting an output of 00:20:00 which is correct but my problem now is its not decrementing even when I have subtracted it am i missing something?
$duration=0;
$startime=date('Y-m-d H:i:s');
$end_time=$end_time=date('Y-m-d H:i:s',
strtotime('+'.$duration.'minutes',strtotime($startime)));
$timefirst=strtotime($startime);
$timesecond=strtotime($end_time);
$differenceinseconds=$timesecond-$timefirst;
echo gmdate("H:i:s", $differenceinseconds);
my script
<div id='response'></div>
<script type="text/javascript">
setInterval(function(){
var xmlhttp=new XMLHttpRequest();
xmlhttp.open("GET",'responseTime.php',false);
xmlhttp.send(null);
document.getElementById('response').innerHTML=xmlhttp.responseText;
},1000);
</script>

As RiggsFolly mentioned why waste servers time running a timer.
Here is what you can do in javascript,
<div id="stopwatch"></div>
<script>
var Stopwatch = function (elem, target, options) {
var timer = createTimer(),
offset,
clock,
interval;
// default options
options = options || {};
options.delay = options.delay || 1;
// append elements
elem.appendChild(timer);
// initialize
reset();
// private functions
function createTimer() {
var interval = 20 ; // 20 seconds
var element = document.createElement("progress");
element.setAttribute("max",interval);
return element;
}
function start() {
if (!interval) {
offset = Date.now();
interval = setInterval(update, options.delay);
}
}
function stop() {
if (interval) {
clearInterval(interval);
interval = null;
}
}
function reset() {
clock = 0;
render();
}
function update() {
clock += delta();
render();
}
function render() {
timer.value = parseInt(clock / 1000);
if(timer.value==interval){
// This is the point where timer ends, put your further code in here.
}
}
function delta() {
var now = Date.now(),
d = now - offset;
offset = now;
return d;
}
// public API
this.start = start;
this.stop = stop;
this.reset = reset;
};
var elem = document.getElementById("stopwatch");
var timer = new Stopwatch(elem, {delay: 10});
timer.start();
</script>

How to Pause the timer on window blur and resume the timer on window focus event?

Thanks for seeing my question.
I am using wp-pro-quiz plugin for quiz. I want to know that how can I pause the timer if the window is not in focus or is blur and resume it when it is back to focus.?
My code:
I get reset when it get focused
var timelimit = (function () {
var _counter = config.timelimit;
var _intervalId = 0;
var instance = {};
instance.stop = function () {
if (_counter) {
window.clearInterval(_intervalId);
globalElements.timelimit.hide();
}
};
instance.start = function () {
var x;
var beforeTime;
if (!_counter)
return;
var $timeText = globalElements.timelimit.find('span').text(plugin.methode.parseTime(_counter));
var $timeDiv = globalElements.timelimit.find('.wpProQuiz_progress');
globalElements.timelimit.show();
$.winFocus(function (event) {
console.log("Blur\t\t", event);
},
function (event) {
console.log("Focus\t\t", event);
x = _counter * 1000;
beforeTime = +new Date();
});
_intervalId = window.setInterval(function () {
var diff = (+new Date() - beforeTime);
var elapsedTime = x - diff;
if (diff >= 500) {
$timeText.text(plugin.methode.parseTime(Math.ceil(elapsedTime / 1000)));
}
$timeDiv.css('width', (elapsedTime / x * 100) + '%');
if (elapsedTime <= 0) {
instance.stop();
plugin.methode.finishQuiz(true);
}
}, 16);
};
return instance;
})();

Use this wrapper function to pause, resume your timeout.
var Timer;
Timer = function(callback, delay) {
var remaining, start, timerId;
timerId = void 0;
start = void 0;
remaining = delay;
this.pause = function() {
window.clearTimeout(timerId);
remaining -= new Date - start;
};
this.resume = function() {
start = new Date;
window.clearTimeout(timerId);
timerId = window.setTimeout(callback, remaining);
};
this.resume();
};
Intialize it like this, timer = new Timer("callback_function_here", 45000)
In this case total time is 45 seconds for the callback and upon event triggers(blur or focus in your case) it will pause or resume the timer accordingly.
timer.pause() //pause the timer
timer.resume() //resume the timer
P.S - Use this function as per the logic of your code. You will have to make the timer calls accordingly in your code

I did it this way:
var time0 ; var setTimeout_Int; var focused = true; var resume_Fun ;
var addTime =0; var addTimeDiff =0;
window.onfocus = function() {
focused = true;
var d = new Date();
addTimeDiff = addTimeDiff +( d.getTime() - addTime );
resume_Fun();
};
window.onblur = function()
{
focused = false;
};
function init()
{
var d = new Date();
time0 = d.getTime();
setTimeout_Int = setTimeout(update, 1000 )
}
function update()
{
clearTimeout(setTimeout_Int);
var d = new Date();
if(focused)
{
if(d.getTime() -(time0+addTimeDiff) < 20000)
{
setTimeout_Int= setTimeout(update, 1000 )
}
}
else
{
addTime = d.getTime();
resume_Fun = update;
}
}
init();

Stopping a Javascript setInterval that is delayed by a setTimeout

I'm having issue with this jsfiddle snippet:
http://jsfiddle.net/y45jN/7/
var mainFunction = function() {
this.text;
this.repeater;
}
var repeatEvery = function(func, interval) {
var now = new Date();
var delay = interval - now % interval;
function start() {
var intervalID = setInterval(func, interval);
func(intervalID);
}
setTimeout(start, delay);
};
mainFunction.prototype.start = function(printText) {
this.text = printText;
var self = this;
var func = function(intervalID) {
if(intervalID){
this.repeater = intervalID;
}
document.getElementById('test').innerHTML += this.text + '<br/>';
};
repeatEvery(_.bind(func, this),1000);
}
mainFunction.prototype.stop = function() {
clearInterval(this.repeater);
}
var test = new mainFunction();
test.start('hello');
setTimeout(test.stop,10000);
My goal is to call the stop function and stop the Interval that has been set by the start function.

You need to do
setTimeout(function(){ test.stop()}, 10000)
or
setTimeout(test.stop.bind(test), 10000); //Bind method is not available in IE8 though
instead of
setTimeout(test.stop, 10000);
The reason for this is that Javascript loses track of the "this" when you pass a callback to a function.

Repeating setTimeout

I am trying to repeat setTimeout every 10 seconds. I know that setTimeout by default only waits and then performs an action one time. How can I repeat the process?
setTimeout(function() {
setTimeout(function() {
console.log("10 seconds");
}, 10000);
}, 10000);

Maybe you should use setInterval()

setInterval() is probably what you're looking for, but if you want to do get the same effect with setTimeout():
function doSomething() {
console.log("10 seconds");
setTimeout(doSomething, 10000);
}
setTimeout(doSomething, 10000);
Or if you don't want to declare a separate function and want to stick with a function expression you need to make it a named function expression:
setTimeout(function doSomething() {
console.log("10 seconds");
setTimeout(doSomething, 10000);
}, 10000);
(Or use arguments.callee if you don't mind using deprecated language features.)

according to me setInterval() is the best way in your case.
here is some code :
setInterval(function() {
//your code
}, 10000);
// you can change your delay by changing this value "10000".

Unlike the answers provided by #nnnnnn and #uzyn I discourage you from making use of setInterval for reasons elaborated in the following answer. Instead make use of the following Delta Timing script:
function DeltaTimer(render, interval) {
var timeout;
var lastTime;
this.start = start;
this.stop = stop;
function start() {
timeout = setTimeout(loop, 0);
lastTime = + new Date;
return lastTime;
}
function stop() {
clearTimeout(timeout);
return lastTime;
}
function loop() {
var thisTime = + new Date;
var deltaTime = thisTime - lastTime;
var delay = Math.max(interval - deltaTime, 0);
timeout = setTimeout(loop, delay);
lastTime = thisTime + delay;
render(thisTime);
}
}
The above script runs the given render function as close as possible to the specified interval, and to answer your question it makes use of setTimeout to repeat a process. In your case you may do something as follows:
var timer = new DeltaTimer(function (time) {
console.log("10 seconds");
}, 10000);
var start = timer.start();

const myFunction = () => {
setTimeout(() => {
document.getElementById('demo').innerHTML = Date();
myFunction();
}, 10000);
}
Easiest, but not efficient way!

Here is a function using setTimeout that tried to call itself as close as it can to a regular interval. If you watch the output, you can see the time drifting and being reset.
<script type="text/javascript">
function Timer(fn, interval) {
this.fn = fn;
this.interval = interval;
}
Timer.prototype.run = function() {
var timer = this;
var timeDiff = this.interval;
var now = new Date(); // Date.now is not supported by IE 8
var newInterval;
// Only run if all is good
if (typeof timer.interval != 'undefined' && timer.fn) {
// Don't do this on the first run
if (timer.lastTime) {
timeDiff = now - timer.lastTime;
}
timer.lastTime = now;
// Adjust the interval
newInterval = 2 * timer.interval - timeDiff;
// Do it
timer.fn();
// Call function again, setting its this correctly
timer.timeout = setTimeout(function(){timer.run()}, newInterval);
}
}
var t = new Timer(function() {
var d = new Date();
document.getElementById('msg').innerHTML = d + ' : ' + d.getMilliseconds();
}, 1000);
window.onload = function() {
t.run();
};
</script>
<span id="msg"></span>

Using jQuery, this is what you could do:
function updatePage() {
var interval = setTimeout(updatePage, 10000); // 10' Seconds
$('a[href]').click(function() {
$(this).data('clicked', true);
clearInterval(interval); // Clears Upon Clicking any href Link
console.log('Interval Cleared!');
});
// REPLACE 'YOUR_FUNCTION_NAME' function you would like to execute
setTimeout(YOUR_FUNCTION_NAME, 500);
} // Function updatePage close syntax
updatePage(); // call the function again.