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Stop setInterval
(6 answers)
Closed 4 years ago.
I am creating a simple JavaScript Timer. Firstly, here's my code that I'm working with:
//Variables used for the timer
var timer = "waiting",
seconds = 0,
minutes = 0,
extraFill1 = "",
extraFill2 = "";
//Check whether to start or stop the timer
function toggleClock() {
if (timer === "waiting") {
setInterval(start, 1000);
timer = "executing";
document.getElementById("btn").innerText = "Stop";
}
else {
clearInterval(start);
timer = "waiting";
document.getElementById("btn").innerText = "Start";
}
}
//Increment seconds and display correctly
function start() {
seconds++;
//Add a leading zero for 1 digit numbers (seconds)
if (seconds < 10 || seconds === 60) {
extraFill1 = "0";
}
else {
extraFill1 = "";
}
//Increment minute when seconds reaches 60
if (seconds === 60) {
minutes += 1;
seconds = 0;
}
//Add a leading zero for 1 digit numbers (minutes)
if (minutes < 10) {
extraFill2 = "0";
}
else {
extraFill2 = "";
}
//display results
document.getElementById("result").innerHTML = extraFill2 + minutes + ":" + extraFill1 + seconds;
}
In my first function toggleClock(), I have stated that if timer !== waiting, then we do clearInterval(start). I would like to clearInterval(start) if timer === "executing. This does not work (which I think is because it has a local scope?). To solve this, I attempted writing:
var myTimer = setInterval(start, 1000);
I planned on calling myTimer when I wanted to start the timer. Instead, the interval kicks off as soon as the page is loaded (and the variable is declared).
How might I set an interval of a function (on button click) with the ability to stop/clear the interval (by pressing the same button) later?
You need to pass to clearInterval the result of your call to setInterval earlier; you don't pass a function to clearInterval, you pass it the intervalID. For example:
let clockInterval;
function toggleClock() {
if (timer === "waiting") {
clockInterval = setInterval(start, 1000);
timer = "executing";
document.getElementById("btn").innerText = "Stop";
}
else {
clearInterval(clockInterval);
timer = "waiting";
document.getElementById("btn").innerText = "Start";
}
}
Related
There is a counter that counts down from 25. When I click on the link of the page, it continues to count from wherever it is left. So when I start at 25 and exit the page, it shows 15 when I come back 10 seconds later. But when I open it with a different browser, there is a different number, so the counter does not always show the same value. What could be the reason for this and what can I do?
var interval = 25000;
function reset() {
localStorage.endTime = +new Date() + interval;
}
if (!localStorage.endTime) {
reset();
}
function millisToMinutesAndSeconds(millis) {
var seconds = ((millis % 60000) / 1000).toFixed(0);
return (seconds < 10 ? "0" : "") + seconds;
}
setInterval(function () {
var remaining = localStorage.endTime - new Date();
if (remaining >= 0) {
document.getElementById("timer").innerText =
millisToMinutesAndSeconds(remaining);
} else {
reset();
}
}, 100);
I am working on a timer that runs for a set amount of minutes, then starts over for a break period that counts down and then goes back to the original amount of minutes. I'm struggling with the logic. So far, I have it running down the original time, then running down the break timer but I need help making it return to the original time and loop this infinitely (or until the stop button is pressed). Here's what I have:
function timer(minutes, breakLength) {
--minutes;
timerId = setInterval(function() {
if (minutes >= 0) {
if (seconds > 0) {
--seconds;
}
if (seconds == 0 && minutes == 0) {
playSound();
isBreak = true;
minutes = breakLength;
$('.type').html('Break');
$('.timer').html(minutes + ':00');
};
if (seconds === 0) {
seconds = 59;
--minutes;
}
if (seconds < 10) {
seconds = '0' + seconds;
}
$('.timer').html(minutes + ':' + seconds);
}
}, 1000);
}
How can I make this repeat itself?
Define a new variable as a timeout id holder (let's call it resetTimeout) in your timer function scope:
var resetTimeout = null;
Add this additional code to the main function
var runFor = 60000; // 60000ms or 1 minute
Add logic in the main interval (first line):
if(runFor <= 0) {
if(!resetTimeout) {
// Create a reset timeout
resetTimeout = setTimeout(function(){ runFor = 60000; resetTimeout = null; }, breakLength);
}
return;
}
else {
runFor -= 1000; // Deduct time of this interval
}
This logic deducts 1000 ms or 1 second from runFor until it is fully consumed. Then creates a timeOut function that will reset it back to its original value and returns the current function until runFor is renewed. I used 60000 ms as an example and you can see the correct version in the full code below. Why do we assign the timeout to a variable? It is simple, we don't want to create more than one timeout. We'll set the timeout to null to allow recreation on the next interval.
Note that there are better ways of doing this but I decided to make as little modifications to your code as possible.
Here is the working code:
function timer(minutes, breakLength) {
var seconds = 0;
var originalMinutes = minutes;
var resetTimeout = null;
var totalRunFor = minutes * 60 * 1000; // Since minutes are independent
var runFor = totalRunFor;
timerId = setInterval(function() {
if(runFor <= 0) {
if(!resetTimeout) {
// Create a reset timeout
resetTimeout = setTimeout(function(){ runFor = totalRunFor; resetTimeout = null; }, breakLength);
}
return;
}
else {
runFor -= 1000; // Deduct time of this interval
}
if (minutes >= 0) {
if (seconds > 0) {
--seconds;
}
if (seconds == 0 && minutes == 0) {
//playSound();
isBreak = true;
minutes = originalMinutes;
$('.type').html('Break');
$('.timer').html(minutes + ':00');
};
if (seconds === 0) {
seconds = 59;
--minutes;
}
$('.timer').html(minutes + ':' + ((seconds < 10)?'0':'') + seconds);
}
}, 1000);
}
timer(1, 10000);
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
Run for a minute and stop for 10 seconds indefinitely.
<div class='type'></div>
<div class='timer'></div>
It may be conceptually easier to seperate this into multiple functions within the timer function
function timer(minutes, breakLength) {
var ci = null;
function ACountdown(minutes, callback) {
var mm = minutes,
ss = 0;
ci = setInterval(function () {
--ss;
if (ss < 0)
ss += 60, --mm;
if (mm < 0) {
// done
clearInterval(ci);
setTimeout(callback, 0);
} else {
$('.timer').html(mm + ':' + seconds);
}
}, 1e3);
}
function A() {
// returned from break
$('.type').html = 'Countdown';
ACountdown(minutes, B);
}
function B() {
// just finished countdown
playSound();
// going on break
$('.type').html = 'Break';
ACountdown(breakLength, A);
}
// set up any click handlers here, e.g.
document.getElementById('cancel_button').addEventListener('click', function c() {
this.removeEventListener('click', c);
clearInterval(ci);
});
// start invocation chain
A();
}
EDIT & UPDATE: for reference I rewrote the whole thing with only 1 timer and a second to time converter. Very clean and less complex. Here is the full code: http://pastebin.com/Hb6cBryL
I got this timer that I built out of javascript: http://powerpoint.azurewebsites.net/
It is quite simple code, but for the final implementation I would need to be able to pause the timer and restart it. I use 2 setIntervalls, 1 for the minutes that triggers every 60s and one for the seconds that triggers every second.
When I pause it I clear the intervals. However when I restart them the minutes restart at the 60 interval and aren't synced with the seconds anymore.
I probably implemented this in a horribly wrong way so I'd like to ask for your advice. 1 idea I had was to continue the inverval but avoid updating the variable and text on the page so that the minutes/seconds stay in sync< However this doesn't sound like an ideal solution to me. All tips are welcome :)
Js code:
var minutes = null, seconds = null, cnt, secs;
function settimer(frm) { if (minutes == null) { cnt = frm.timeinput.value - '1'; secs = '59';} };
function stop() {
clearInterval(minutes);
clearInterval(seconds);
minutes = null;
seconds = null;
document.getElementById("minutes").innerHTML = '00';
document.getElementById("seconds").innerHTML = '00';
}
function pause() {
clearInterval(minutes);
clearInterval(seconds);
}
function runtimer() {
event.preventDefault();
if (minutes == null) {
document.getElementById("minutes").innerHTML = cnt;};
minutes = setInterval(function () {
if (cnt == '0') { stop() } else { cnt -= 1; document.getElementById("minutes").innerHTML = cnt; };
}, 6000);
if (seconds == null) { document.getElementById("seconds").innerHTML = secs; };
seconds = setInterval(function () {
if (secs == '0') { secs = '59' } else { secs -= 1; document.getElementById("seconds").innerHTML = secs; };
}, 100);
}
You'll need to wrap them somehow, and recognise that you can't immediately get the timer's id.
function setIntervalWithOffset(fn, delay, offset) {
var o = {id: null, o_id: null};
o.o_id = window.setTimeout(function () {
o.id = window.setInterval(fn, delay);
}, offset);
return o;
}
function setTimeoutWithOffset(fn, delay, offset) {
var o = {id: null, o_id: null};
o.o_id = window.setTimeout(function () {
o.id = window.setTimeout(fn, delay);
}, offset);
return o;
}
To clear, use window.clearTimeout on obj.o_id and whichever type you set for obj.id.
You should also consider whether you'd be better off implementing a setTimeout loop rather than using setInterval so you don't have a chance of a cascade error
Sorry, I think that you are in a bad way. Why do you want to use two intervals to do the same thing? Intervals are asynchronous, you can not synchronize two intervals that runs independently.
You can achieve that with just one interval. To show seconds, you can just increment another variable each time that your counter reachs a threshold:
var counter = 0;
var seconds = 0;
var $interval = setInterval(function(){
counter++;
if (counter >= 6000) {
counter = counter - 6000;
seconds++;
}
, 10);
So, it will be more easy to stop/restart your interval.
You need to get the handle to the timer, in order to be able to reset it later, you can do like below:
timeoutHandle = setTimeout(function(){/*code*/}, 1000);
clearTimeout(timeoutHandle);
Take a look at this jsfiddle
Taken from : How do I stop a window.setInterval in javascript?
I am trying to make a timer using JavaScript. The problem is, I can't get the timer to stop when it reaches 0. I have tried using return and if statements, but nothing seems to be working. Am I on the right track, or is there a better way to do this?
<input type="text" id="minutes" style="width:30px;text-align:center" maxlength="2" placeholder="00">
<span>:</span>
<input type="text" id="seconds" style="width:30px;text-align:center" maxlength="2" placeholder="00">
<button onclick="timer()">Set</button>
<script>
//This prototype correctly uses the modulus function when dealing with negative numbers.
Number.prototype.mod = function (m) {
return ((this % m) + m) % m
}
function timer() {
var minutes = document.getElementById('minutes').value //Value of minutes box.
var seconds = document.getElementById('seconds').value //Value of seconds box.
var initial = seconds * 1000 //Amount of seconds (converted to milliseconds) initially set.
var milliseconds = (minutes * 60000) + (seconds * 1000) //Total amount of milliseconds set.
setTimeout(function () {
alert("Time's up!")
}, milliseconds) //Display a message when the set time is up.
/*\Decreases the minute by one after the initially set amount of seconds have passed.
|*|Then, clears the interval and sets a new one to decrease the minute every 60 seconds.
\*/
test = setInterval(function () {
minutes--;
document.getElementById('minutes').value = minutes;
clearInterval(test)
setInterval(function () {
minutes--;
document.getElementById('minutes').value = minutes
}, 60000)
}, initial)
//Seconds are set to decrease by one every 1000 milliseconds, then be displayed in the seconds box.
setInterval(function () {
seconds--;
document.getElementById('seconds').value = seconds.mod(60)
}, 1000)
}
You have four different timer functions (setTimer and two setIntervals) when you only need one. JSFiddle
function timer() {
var minutes = document.getElementById('minutes').value //Value of minutes box.
var seconds = document.getElementById('seconds').value //Value of seconds box.
var intervalTimer = setInterval(function () {
seconds--;
if (seconds < 0) {
seconds = 59;
minutes--;
}
document.getElementById('minutes').value = minutes;
document.getElementById('seconds').value = seconds;
if (minutes == 0 && seconds == 0) {
alert("Time's up!");
clearInterval(intervalTimer);
}
}, 1000);
}
In general, you need to make sure every setInterval is given a name (var x = setInterval...) and cleared later on (clearInterval(x)). You could have separate timers (one for the minutes which starts after the given number of seconds then repeats every 60 seconds, one for seconds, and one to display the message) if you really want to for some reason, as long as you clear all of the interval timers once the countdown reaches zero.
Using two timers might make sense, however. This would make sure that the Time's up message really appears when it's supposed to, even if there is any imprecision in the interval timer.
function timer() {
var minutes = document.getElementById('minutes').value,
seconds = document.getElementById('seconds').value,
intervalTimer = setInterval(function () {
seconds--;
if (seconds < 0) {
seconds = 59;
minutes--;
}
document.getElementById('minutes').value = minutes;
document.getElementById('seconds').value = seconds;
}, 1000);
setTimer(function () {
alert("Time's up!");
clearInterval(intervalTimer);
}, minutes * 60000 + seconds * 1000);
}
I made improvements to Stuart's answer: fiddle
Basically the same thing, except it works properly:
function clearTimer() {
clearInterval(intervalTimer);
}
var intervalTimer;
function timer() {
var minutes = document.getElementById('minutes').value //Value of minutes box.
var seconds = document.getElementById('seconds').value //Value of seconds box.
intervalTimer = setInterval(function () {
seconds--;
if (seconds < 0) {
seconds += 60;
minutes--;
}
if (minutes < 0) {
alert("Time's up!");
clearTimer();
} else {
document.getElementById('minutes').value = minutes;
document.getElementById('seconds').value = seconds;
}
}, 1000);
}
Im not a great javascript guy, but maybe this will help. i made this in typescript http://www.typescriptlang.org/Playground/
but i would do timing different and use the javascript date object and calculate differences. This is a simple example of how i would start to create a time (without the date object)
javascript
var Timer = (function () {
function Timer(time) {
this.accuracy = 1000;
this.time = time;
}
Timer.prototype.run = function (button) {
var _this = this;
this.time -= 1; //this is inaccurate, for accurate time use the date objects and calculate the difference.
//http://www.w3schools.com/js/js_obj_date.asp
button.textContent = this.time.toString();
if (this.time > 0) {
setTimeout(function () {
return _this.run(button);
}, 1000);
}
};
return Timer;
})();
var time = new Timer(10);
var button = document.createElement('button');
time.run(button);
document.body.appendChild(button);
typescript(in case you wonder)
class Timer {
accuracy = 1000;//update every second
time: number;
constructor(time: number) {
this.time = time;
}
run(button: HTMLButtonElement) {
this.time -=1;//this is inaccurate, for accurate time use the date objects and calculate the difference.
//http://www.w3schools.com/js/js_obj_date.asp
button.textContent = this.time.toString();
if(this.time > 0)
{
setTimeout(()=> this.run(button),1000);
}
}
}
var time = new Timer(10)
var button = document.createElement('button');
time.run(button);
document.body.appendChild(button);
I am trying to build multiple timers for my web page, so far I have,
$('.timer').each(function() {
var timer = setInterval(function() {
var time = $(this).text().split(':');
var minutes = parseInt(time[0], 10);
var seconds = parseInt(time[1], 10);
// TIMER RUN OUT
if (!minutes && !seconds) {
// CLEAR TIMER
clearInterval(timer);
// MINUS SECONDS
} else {
seconds -= 1;
}
// MINUS MINUTES
if (seconds < 0 && minutes != 0) {
minutes -= 1;
seconds = 59;
// ADD ZERO IF SECONDS LESS THAN 10
} else {
if (seconds < 10) {
seconds = '0' + seconds;
}
}
// ADD ZERO IF MINUTES LESS THAN 10
if (minutes < 10) {
minutes = '0' + minutes;
}
}, 1000);
});
This doesn't work though! Where am I going wrong!
Thanks
First, inside your setInterval callback, this no longer refers to the .timer element. Try changing that to self and add var self = this; before the call to setInterval. Second, you never write your time back to your .timer element.
Are you trying to display a clock counting down? In that case, you're not updating the text after all the calculations. Try adding:
$(this).text(minutes+':'+seconds);