Related
I have written a javascript function that uses setInterval to manipulate a string every tenth of a second for a certain number of iterations.
function timer() {
var section = document.getElementById('txt').value;
var len = section.length;
var rands = new Array();
for (i=0; i<len; i++) {
rands.push(Math.floor(Math.random()*len));
};
var counter = 0
var interval = setInterval(function() {
var letters = section.split('');
for (j=0; j < len; j++) {
if (counter < rands[j]) {
letters[j] = Math.floor(Math.random()*9);
};
};
document.getElementById('txt').value = letters.join('');
counter++
if (counter > rands.max()) {
clearInterval(interval);
}
}, 100);
};
Instead of having the interval set at a specific number, I would like to update it every time it runs, based on a counter. So instead of:
var interval = setInterval(function() { ... }, 100);
It would be something like:
var interval = setInterval(function() { ... }, 10*counter);
Unfortunately, that did not work. It seemed like "10*counter" equals 0.
So, how can I adjust the interval every time the anonymous function runs?
You could use an anonymous function:
var counter = 10;
var myFunction = function(){
clearInterval(interval);
counter *= 10;
interval = setInterval(myFunction, counter);
}
var interval = setInterval(myFunction, counter);
UPDATE: As suggested by A. Wolff, use setTimeout to avoid the need for clearInterval.
var counter = 10;
var myFunction = function() {
counter *= 10;
setTimeout(myFunction, counter);
}
setTimeout(myFunction, counter);
Use setTimeout() instead. The callback would then be responsible for firing the next timeout, at which point you can increase or otherwise manipulate the timing.
EDIT
Here's a generic function you can use to apply a "decelerating" timeout for ANY function call.
function setDeceleratingTimeout(callback, factor, times)
{
var internalCallback = function(tick, counter) {
return function() {
if (--tick >= 0) {
window.setTimeout(internalCallback, ++counter * factor);
callback();
}
}
}(times, 0);
window.setTimeout(internalCallback, factor);
};
// console.log() requires firebug
setDeceleratingTimeout(function(){ console.log('hi'); }, 10, 10);
setDeceleratingTimeout(function(){ console.log('bye'); }, 100, 10);
I like this question - inspired a little timer object in me:
window.setVariableInterval = function(callbackFunc, timing) {
var variableInterval = {
interval: timing,
callback: callbackFunc,
stopped: false,
runLoop: function() {
if (variableInterval.stopped) return;
var result = variableInterval.callback.call(variableInterval);
if (typeof result == 'number')
{
if (result === 0) return;
variableInterval.interval = result;
}
variableInterval.loop();
},
stop: function() {
this.stopped = true;
window.clearTimeout(this.timeout);
},
start: function() {
this.stopped = false;
return this.loop();
},
loop: function() {
this.timeout = window.setTimeout(this.runLoop, this.interval);
return this;
}
};
return variableInterval.start();
};
Example use
var vi = setVariableInterval(function() {
// this is the variableInterval - so we can change/get the interval here:
var interval = this.interval;
// print it for the hell of it
console.log(interval);
// we can stop ourselves.
if (interval>4000) this.stop();
// we could return a new interval after doing something
return interval + 100;
}, 100);
// we can change the interval down here too
setTimeout(function() {
vi.interval = 3500;
}, 1000);
// or tell it to start back up in a minute
setTimeout(function() {
vi.interval = 100;
vi.start();
}, 60000);
I had the same question as the original poster, did this as a solution. Not sure how efficient this is ....
let interval = 5000; // initial condition
let run = setInterval(request, interval); // start setInterval as "run"
function request() {
console.log(interval); // firebug or chrome log
clearInterval(run); // stop the setInterval()
// dynamically change the run interval
if (interval > 200) {
interval = interval * .8;
} else {
interval = interval * 1.2;
}
run = setInterval(request, interval); // start the setInterval()
}
This is my way of doing this, i use setTimeout:
var timer = {
running: false,
iv: 5000,
timeout: false,
cb : function(){},
start : function(cb,iv){
var elm = this;
clearInterval(this.timeout);
this.running = true;
if(cb) this.cb = cb;
if(iv) this.iv = iv;
this.timeout = setTimeout(function(){elm.execute(elm)}, this.iv);
},
execute : function(e){
if(!e.running) return false;
e.cb();
e.start();
},
stop : function(){
this.running = false;
},
set_interval : function(iv){
clearInterval(this.timeout);
this.start(false, iv);
}
};
Usage:
timer.start(function(){
console.debug('go');
}, 2000);
timer.set_interval(500);
timer.stop();
A much simpler way would be to have an if statement in the refreshed function and a control to execute your command at regular time intervals . In the following example, I run an alert every 2 seconds and the interval (intrv) can be changed dynamically...
var i=1;
var intrv=2; // << control this variable
var refreshId = setInterval(function() {
if(!(i%intrv)) {
alert('run!');
}
i++;
}, 1000);
This can be initiated however you want. timeout is the method i used to keep it on the top of the hour.
I had the need for every hour to begin a code block on the hour. So this would start at server startup and run the interval hourly. Basicaly the initial run is to begin the interval within the same minute. So in a second from init, run immediately then on every 5 seconds.
var interval = 1000;
var timing =function(){
var timer = setInterval(function(){
console.log(interval);
if(interval == 1000){ /*interval you dont want anymore or increment/decrement */
interval = 3600000; /* Increment you do want for timer */
clearInterval(timer);
timing();
}
},interval);
}
timing();
Alternately if you wanted to just have something happen at start and then forever at a specific interval you could just call it at the same time as the setInterval. For example:
var this = function(){
//do
}
setInterval(function(){
this()
},3600000)
this()
Here we have this run the first time and then every hour.
I couldn't synchronize and change the speed my setIntervals too and I was about to post a question. But I think I've found a way. It should certainly be improved because I'm a beginner. So, I'd gladly read your comments/remarks about this.
<body onload="foo()">
<div id="count1">0</div>
<div id="count2">2nd counter is stopped</div>
<button onclick="speed0()">pause</button>
<button onclick="speedx(1)">normal speed</button>
<button onclick="speedx(2)">speed x2</button>
<button onclick="speedx(4)">speed x4</button>
<button onclick="startTimer2()">Start second timer</button>
</body>
<script>
var count1 = 0,
count2 = 0,
greenlight = new Boolean(0), //blocks 2nd counter
speed = 1000, //1second
countingSpeed;
function foo(){
countingSpeed = setInterval(function(){
counter1();
counter2();
},speed);
}
function counter1(){
count1++;
document.getElementById("count1").innerHTML=count1;
}
function counter2(){
if (greenlight != false) {
count2++;
document.getElementById("count2").innerHTML=count2;
}
}
function startTimer2(){
//while the button hasn't been clicked, greenlight boolean is false
//thus, the 2nd timer is blocked
greenlight = true;
counter2();
//counter2() is greenlighted
}
//these functions modify the speed of the counters
function speed0(){
clearInterval(countingSpeed);
}
function speedx(a){
clearInterval(countingSpeed);
speed=1000/a;
foo();
}
</script>
If you want the counters to begin to increase once the page is loaded, put counter1() and counter2() in foo() before countingSpeed is called. Otherwise, it takes speed milliseconds before execution.
EDIT : Shorter answer.
(function variableInterval() {
//whatever needs to be done
interval *= 2; //deal with your interval
setTimeout(variableInterval, interval);
//whatever needs to be done
})();
can't get any shorter
Here is yet another way to create a decelerating/accelerating interval timer. The interval gets multiplied by a factor until a total time is exceeded.
function setChangingInterval(callback, startInterval, factor, totalTime) {
let remainingTime = totalTime;
let interval = startInterval;
const internalTimer = () => {
remainingTime -= interval ;
interval *= factor;
if (remainingTime >= 0) {
setTimeout(internalTimer, interval);
callback();
}
};
internalTimer();
}
Make new function:
// set Time interval
$("3000,18000").Multitimeout();
jQuery.fn.extend({
Multitimeout: function () {
var res = this.selector.split(",");
$.each(res, function (index, val) { setTimeout(function () {
//...Call function
temp();
}, val); });
return true;
}
});
function temp()
{
alert();
}
This piece of code below accelerates (acceleration > 1) or decelerates (acceleration <1) a setInterval function :
function accelerate(yourfunction, timer, refresh, acceleration) {
var new_timer = timer / acceleration;
var refresh_init = refresh;//save this user defined value
if (refresh < new_timer ){//avoid reseting the interval before it has produced anything.
refresh = new_timer + 1 ;
};
var lastInter = setInterval(yourfunction, new_timer);
console.log("timer:", new_timer);
function stopLastInter() {
clearInterval(lastInter);
accelerate(yourfunction, new_timer, refresh_init, acceleration);
console.log("refresh:", refresh);
};
setTimeout(stopLastInter, refresh);
}
With :
timer: the setInterval initial value in ms (increasing or decreasing)
refresh: the time before a new value of timer is calculated. This is the step lenght
acceleration: the gap between the old and the next timer value. This is the step height
Inspired by the internal callback above, i made a function to fire a callback at fractions of minutes. If timeout is set to intervals like 6 000, 15 000, 30 000, 60 000 it will continuously adapt the intervals in sync to the exact transition to the next minute of your system clock.
//Interval timer to trigger on even minute intervals
function setIntervalSynced(callback, intervalMs) {
//Calculate time to next modulus timer event
var betterInterval = function () {
var d = new Date();
var millis = (d.getMinutes() * 60 + d.getSeconds()) * 1000 + d.getMilliseconds();
return intervalMs - millis % intervalMs;
};
//Internal callback
var internalCallback = function () {
return function () {
setTimeout(internalCallback, betterInterval());
callback();
}
}();
//Initial call to start internal callback
setTimeout(internalCallback, betterInterval());
};
This is my idea for times when you do not want loops like setInterval to overlap.
You also want to be able to set the loop execution delay and start and stop the loop, instansly on the fly.
I am using a loop_flag variable and a setTimeout function.
I set the main function to async so that you can call other functions in the body by calling await. When the main body of your code is running, the main loop waits and does not repeat itself. (which is not the case with setInterval)
An example of a simple code is:
//#NabiKAZ
document.getElementById("btn_start").addEventListener("click", function() {
console.log("Starting...");
loop_flag = true;
loop_func();
});
document.getElementById("btn_stop").addEventListener("click", function() {
console.log("Stoping...");
loop_flag = false;
});
var n = 0;
var loop_flag = false;
var loop_func = async function() {
if (!loop_flag) {
console.log("STOP.");
return;
}
//body main function inhere
n++;
console.log(n);
////
if (loop_flag) {
setTimeout(loop_func, document.getElementById("inp_delay").value);
} else {
console.log("STOP.");
}
}
<input id="inp_delay" value="1000">
<button id="btn_start">START</button>
<button id="btn_stop">STOP</button>
For a more complete code with a fetch request inside the loop, see here:
https://jsfiddle.net/NabiKAZ/a5hdw2bo/
You can use a variable and change the variable instead.
setInterval(() => function, variable)
You can do this by clearing the interval every iteration, changing the timer value and setting the interval again. Hope it helps ;)
For exemple:
const DOMCounter = document.querySelector(".counter")
let timer = 1000
const changeCounter = () => {
clearInterval(interval)
DOMCounter.innerHTML = timer
timer += 1000
timer == 5000 && timer == 1000
interval = setInterval(changeCounter, timer)
}
let interval = setInterval(changeCounter, timer)
<div class="container">
<p class="counter"></p>
</div>
var counter = 15;
var interval = function() {
setTimeout(function(){
// Write your code here and remove console.log, remember that you need declare yourDynamicValue and give it a value
console.log((new Date()).getTime())
window.counter = yourDynamicValue;
window.interval();
}, counter);
}
// It needs to run just once as init
interval();
How do I pause and resume the setInterval() function using Javascript?
For example, maybe I have a stopwatch to tell you the number of seconds that you have been looking at the webpage. There is a 'Pause' and 'Resume' button. The reason why clearInterval() would not work here is because if the user clicks on the 'Pause' button at the 40th second and 800th millisecond, when he clicks on the 'Resume' button, the number of seconds elapsed must increase by 1 after 200 milliseconds. If I use the clearInterval() function on the timer variable (when the pause button is clicked) and then using the setInterval() function on the timer variable again (when the resume button is clicked), the number of seconds elapsed will increase by 1 only after 1000 milliseconds, which destroys the accuracy of the stopwatch.
So how do I do that?
You could use a flag to keep track of the status:
var output = $('h1');
var isPaused = false;
var time = 0;
var t = window.setInterval(function() {
if(!isPaused) {
time++;
output.text("Seconds: " + time);
}
}, 1000);
//with jquery
$('.pause').on('click', function(e) {
e.preventDefault();
isPaused = true;
});
$('.play').on('click', function(e) {
e.preventDefault();
isPaused = false;
});
h1 {
font-family: Helvetica, Verdana, sans-serif;
font-size: 12px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<h1>Seconds: 0</h1>
<button class="play">Play</button>
<button class="pause">Pause</button>
This is just what I would do, I'm not sure if you can actually pause the setInterval.
Note: This system is easy and works pretty well for applications that don't require a high level of precision, but it won't consider the time elapsed in between ticks: if you click pause after half a second and later click play your time will be off by half a second.
You shouldn't measure time in interval function. Instead just save time when timer was started and measure difference when timer was stopped/paused. Use setInterval only to update displayed value. So there is no need to pause timer and you will get best possible accuracy in this way.
While #Jonas Giuro is right when saying that:
You cannot PAUSE the setInterval function, you can either STOP it (clearInterval), or let it run
On the other hand this behavior can be simulated with approach #VitaliyG suggested:
You shouldn't measure time in interval function. Instead just save time when timer was started and measure difference when timer was stopped/paused. Use setInterval only to update displayed value.
var output = $('h1');
var isPaused = false;
var time = new Date();
var offset = 0;
var t = window.setInterval(function() {
if(!isPaused) {
var milisec = offset + (new Date()).getTime() - time.getTime();
output.text(parseInt(milisec / 1000) + "s " + (milisec % 1000));
}
}, 10);
//with jquery
$('.toggle').on('click', function(e) {
e.preventDefault();
isPaused = !isPaused;
if (isPaused) {
offset += (new Date()).getTime() - time.getTime();
} else {
time = new Date();
}
});
h1 {
font-family: Helvetica, Verdana, sans-serif;
font-size: 12px;
}
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<h1>Seconds: 0</h1>
<button class="toggle">Toggle</button>
Why not use a simpler approach? Add a class!
Simply add a class that tells the interval not to do anything. For example: on hover.
var i = 0;
this.setInterval(function() {
if(!$('#counter').hasClass('pauseInterval')) { //only run if it hasn't got this class 'pauseInterval'
console.log('Counting...');
$('#counter').html(i++); //just for explaining and showing
} else {
console.log('Stopped counting');
}
}, 500);
/* In this example, I'm adding a class on mouseover and remove it again on mouseleave. You can of course do pretty much whatever you like */
$('#counter').hover(function() { //mouse enter
$(this).addClass('pauseInterval');
},function() { //mouse leave
$(this).removeClass('pauseInterval');
}
);
/* Other example */
$('#pauseInterval').click(function() {
$('#counter').toggleClass('pauseInterval');
});
body {
background-color: #eee;
font-family: Calibri, Arial, sans-serif;
}
#counter {
width: 50%;
background: #ddd;
border: 2px solid #009afd;
border-radius: 5px;
padding: 5px;
text-align: center;
transition: .3s;
margin: 0 auto;
}
#counter.pauseInterval {
border-color: red;
}
<!-- you'll need jQuery for this. If you really want a vanilla version, ask -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<p id="counter"> </p>
<button id="pauseInterval">Pause</button></p>
I've been looking for this fast and easy approach for ages, so I'm posting several versions to introduce as many people to it as possible.
i wrote a simple ES6 class that may come handy.
inspired by https://stackoverflow.com/a/58580918/4907364 answer
export class IntervalTimer {
callbackStartTime;
remaining = 0;
paused = false;
timerId = null;
_callback;
_delay;
constructor(callback, delay) {
this._callback = callback;
this._delay = delay;
}
pause() {
if (!this.paused) {
this.clear();
this.remaining = new Date().getTime() - this.callbackStartTime;
this.paused = true;
}
}
resume() {
if (this.paused) {
if (this.remaining) {
setTimeout(() => {
this.run();
this.paused = false;
this.start();
}, this.remaining);
} else {
this.paused = false;
this.start();
}
}
}
clear() {
clearInterval(this.timerId);
}
start() {
this.clear();
this.timerId = setInterval(() => {
this.run();
}, this._delay);
}
run() {
this.callbackStartTime = new Date().getTime();
this._callback();
}
}
usage is pretty straightforward,
const interval = new IntervalTimer(console.log('aaa'), 3000);
interval.start();
interval.pause();
interval.resume();
interval.clear();
My simple way:
function Timer (callback, delay) {
let callbackStartTime
let remaining = 0
this.timerId = null
this.paused = false
this.pause = () => {
this.clear()
remaining -= Date.now() - callbackStartTime
this.paused = true
}
this.resume = () => {
window.setTimeout(this.setTimeout.bind(this), remaining)
this.paused = false
}
this.setTimeout = () => {
this.clear()
this.timerId = window.setInterval(() => {
callbackStartTime = Date.now()
callback()
}, delay)
}
this.clear = () => {
window.clearInterval(this.timerId)
}
this.setTimeout()
}
How to use:
let seconds = 0
const timer = new Timer(() => {
seconds++
console.log('seconds', seconds)
if (seconds === 8) {
timer.clear()
alert('Game over!')
}
}, 1000)
timer.pause()
console.log('isPaused: ', timer.paused)
setTimeout(() => {
timer.resume()
console.log('isPaused: ', timer.paused)
}, 2500)
function Timer (callback, delay) {
let callbackStartTime
let remaining = 0
this.timerId = null
this.paused = false
this.pause = () => {
this.clear()
remaining -= Date.now() - callbackStartTime
this.paused = true
}
this.resume = () => {
window.setTimeout(this.setTimeout.bind(this), remaining)
this.paused = false
}
this.setTimeout = () => {
this.clear()
this.timerId = window.setInterval(() => {
callbackStartTime = Date.now()
callback()
}, delay)
}
this.clear = () => {
window.clearInterval(this.timerId)
}
this.setTimeout()
}
The code is written quickly and did not refactored, raise the rating of my answer if you want me to improve the code and give ES2015 version (classes).
I know this thread is old, but this could be another solution:
var do_this = null;
function y(){
// what you wanna do
}
do_this = setInterval(y, 1000);
function y_start(){
do_this = setInterval(y, 1000);
};
function y_stop(){
do_this = clearInterval(do_this);
};
The following code, provides a precision way to pause resume a timer.
How it works:
When the timer is resumed after a pause, it generates a correction cycle using a single timeout, that will consider the pause offset (exact time when the timer was paused between cycles). After the correction cycle finishes, it schedules the following cycles with a regular setInteval, and continues normally the cycle execution.
This allows to pause/resume the timer, without losing the sync.
Code :
function Timer(_fn_callback_ , _timer_freq_){
let RESUME_CORRECTION_RATE = 2;
let _timer_statusCode_;
let _timer_clockRef_;
let _time_ellapsed_; // will store the total time ellapsed
let _time_pause_; // stores the time when timer is paused
let _time_lastCycle_; // stores the time of the last cycle
let _isCorrectionCycle_;
/**
* execute in each clock cycle
*/
const nextCycle = function(){
// calculate deltaTime
let _time_delta_ = new Date() - _time_lastCycle_;
_time_lastCycle_ = new Date();
_time_ellapsed_ += _time_delta_;
// if its a correction cicle (caused by a pause,
// destroy the temporary timeout and generate a definitive interval
if( _isCorrectionCycle_ ){
clearTimeout( _timer_clockRef_ );
clearInterval( _timer_clockRef_ );
_timer_clockRef_ = setInterval( nextCycle , _timer_freq_ );
_isCorrectionCycle_ = false;
}
// execute callback
_fn_callback_.apply( timer, [ timer ] );
};
// initialize timer
_time_ellapsed_ = 0;
_time_lastCycle_ = new Date();
_timer_statusCode_ = 1;
_timer_clockRef_ = setInterval( nextCycle , _timer_freq_ );
// timer public API
const timer = {
get statusCode(){ return _timer_statusCode_ },
get timestamp(){
let abstime;
if( _timer_statusCode_=== 1 ) abstime = _time_ellapsed_ + ( new Date() - _time_lastCycle_ );
else if( _timer_statusCode_=== 2 ) abstime = _time_ellapsed_ + ( _time_pause_ - _time_lastCycle_ );
return abstime || 0;
},
pause : function(){
if( _timer_statusCode_ !== 1 ) return this;
// stop timers
clearTimeout( _timer_clockRef_ );
clearInterval( _timer_clockRef_ );
// set new status and store current time, it will be used on
// resume to calculate how much time is left for next cycle
// to be triggered
_timer_statusCode_ = 2;
_time_pause_ = new Date();
return this;
},
resume: function(){
if( _timer_statusCode_ !== 2 ) return this;
_timer_statusCode_ = 1;
_isCorrectionCycle_ = true;
const delayEllapsedTime = _time_pause_ - _time_lastCycle_;
_time_lastCycle_ = new Date( new Date() - (_time_pause_ - _time_lastCycle_) );
_timer_clockRef_ = setTimeout( nextCycle , _timer_freq_ - delayEllapsedTime - RESUME_CORRECTION_RATE);
return this;
}
};
return timer;
};
let myTimer = Timer( x=> console.log(x.timestamp), 1000);
<input type="button" onclick="myTimer.pause()" value="pause">
<input type="button" onclick="myTimer.resume()" value="resume">
Code source :
This Timer is a modified and simplified version of advanced-timer, a js library created by myself, with many more functionalities.
The full library and documentation is available in NPM and GITHUB
let time = document.getElementById("time");
let stopButton = document.getElementById("stop");
let timeCount = 0,
currentTimeout;
function play() {
stopButton.hidden = false;
clearInterval(currentTimeout);
currentTimeout = setInterval(() => {
timeCount++;
const min = String(Math.trunc(timeCount / 60)).padStart(2, 0);
const sec = String(Math.trunc(timeCount % 60)).padStart(2, 0);
time.innerHTML = `${min} : ${sec}`;
}, 1000);
}
function pause() {
clearInterval(currentTimeout);
}
function stop() {
stopButton.hidden = true;
pause();
timeCount = 0;
time.innerHTML = `00 : 00`;
}
<div>
<h1 id="time">00 : 00</h1>
<br />
<div>
<button onclick="play()">play</button>
<button onclick="pause()">pause</button>
<button onclick="stop()" id="stop" hidden>Reset</button>
</div>
</div>
So I'm trying to get a function to run once every second, and then after four seconds I want it to stop using clearInterval()
function dotdotdot(){
var x = 0;
setInterval(function(){
if (x>=3){
torpWri = torpWri + ".";
document.getElementById("torpTxt").innerHTML = torpWri;
x++;
}
else{
x = 0;
clearInterval();
}
},1000);
}
This is my function and it should stop after four seconds and then reset x to 0 for when I call it again.
function loadButton(){
torpWri = "Torpedo Loading"
if(torpLoadAmount[arNum]<5){
torpLoadAmount[arNum]++;
torpAmount--;
document.getElementById("torpCnt").innerHTML = torpAmount;
document.getElementById("torpTxt").style.visibility = "visible";
document.getElementById("butunload").disabled=true;
document.getElementById("butfire").disabled=true;
document.getElementById("torpTxt").innerHTML = torpWri;
dotdotdot();
}
else{
document.getElementById("torpTxt").style.visibility = "visible";
document.getElementById("torpTxt").innerHTML = "Torpedo Bay Full";
}
timer3();
}
This is how I'm calling it.
I'm just needed to know why it isn't running the function dotdotdot(); every second and then stopping after four. Then when I call it again it should all just reset. But it's not running...
I've been searching for a while and haven't found anything, so I came here.
(Also, please don't comment on my other code, I know there are probably easier ways to do it, but this is what I'm working with right now.)
setInterval returns a timerID, which needs to be passed to clearInterval.
var ticks = 0;
var intervalID = setInterval(function() {
if (++ticks == 4) {
clearInterval(intervalID);
}
}, 1000);
You could also use setTimeout instead, and just not schedule a new tick when the condition is met.
setTimeout(function callback(ticks) {
if (ticks > limit) {
return;
}
setTimeout(callback, 0, ++ticks);
}, 1000, 0)
You need to store the handle / intervalId for the interval when it is set and then use it when you want to clear the interval:
function dotdotdot(){
var x = 0;
var intervalId = -1;
intervalId = setInterval(function(){
if (x>=3){
torpWri = torpWri + ".";
document.getElementById("torpTxt").innerHTML = torpWri;
x++;
} else {
x = 0;
clearInterval(intervalId);
}
},1000);
}
More info: https://developer.mozilla.org/en-US/Add-ons/Code_snippets/Timers
setInterval will return a timerid. So do like
var timer = setInterval(fun......)
Then
clearInterval(timer)
var sec = 10
var timer = setInterval(function() {
$('#timer span').text(sec--);
if (sec == -1) {
clearInterval(timer);
} }, 1000);
html
<div id="timer"><span>10</span> seconds</div>
Recount
What I want to do when I click recount is to recount back to 10 seconds the timer?
How can I possibly done it?
It is better to use setInterval() or setTimeout()?
Factor out your code into functions so you can call the same code on startup or when the link is clicked. You can see it working here: http://jsfiddle.net/jfriend00/x3S7j/. This even allows you to click the link during the countdown and it will start over.
$("#recount").click(function() {
initCounter(10);
});
var remainingTime;
var runningInterval = null;
function initCounter(duration) {
function stopCounter() {
if (runningInterval) {
clearInterval(runningInterval);
runningInterval = null;
}
}
stopCounter(); // stop previously running timer
remainingTime = duration; // init duration
$('#timer span').text(remainingTime); // set initial time remaining
runningInterval = setInterval(function() { // start new interval
$('#timer span').text(remainingTime--);
if (remainingTime < 0) {
stopCounter();
}
}, 1000);
}
initCounter(10);
You can just add a click handler and factor out your code in a separate method:
var sec = 10;
var timer;
function startCountdown() {
if (timer) clearInterval(timer);
sec = 10;
timer = setInterval(function() {
$('#timer span').text(sec--);
if (sec == -1) {
clearInterval(timer);
}
}, 1000);
}
$(function() {
startCountdown();
$("#recount").click(startCountdown);
});
Working JSFiddle
When you click recount, you should
sec = 10;
clearInterval(timer);
timer = setInterval(that_function, 1000);
Also, there's a difference between setInterval and setTimeout. setInterval schedules the function to be called every some milliseconds. setTimeout schedules the function to be called once, after some milliseconds.
I have written a javascript function that uses setInterval to manipulate a string every tenth of a second for a certain number of iterations.
function timer() {
var section = document.getElementById('txt').value;
var len = section.length;
var rands = new Array();
for (i=0; i<len; i++) {
rands.push(Math.floor(Math.random()*len));
};
var counter = 0
var interval = setInterval(function() {
var letters = section.split('');
for (j=0; j < len; j++) {
if (counter < rands[j]) {
letters[j] = Math.floor(Math.random()*9);
};
};
document.getElementById('txt').value = letters.join('');
counter++
if (counter > rands.max()) {
clearInterval(interval);
}
}, 100);
};
Instead of having the interval set at a specific number, I would like to update it every time it runs, based on a counter. So instead of:
var interval = setInterval(function() { ... }, 100);
It would be something like:
var interval = setInterval(function() { ... }, 10*counter);
Unfortunately, that did not work. It seemed like "10*counter" equals 0.
So, how can I adjust the interval every time the anonymous function runs?
You could use an anonymous function:
var counter = 10;
var myFunction = function(){
clearInterval(interval);
counter *= 10;
interval = setInterval(myFunction, counter);
}
var interval = setInterval(myFunction, counter);
UPDATE: As suggested by A. Wolff, use setTimeout to avoid the need for clearInterval.
var counter = 10;
var myFunction = function() {
counter *= 10;
setTimeout(myFunction, counter);
}
setTimeout(myFunction, counter);
Use setTimeout() instead. The callback would then be responsible for firing the next timeout, at which point you can increase or otherwise manipulate the timing.
EDIT
Here's a generic function you can use to apply a "decelerating" timeout for ANY function call.
function setDeceleratingTimeout(callback, factor, times)
{
var internalCallback = function(tick, counter) {
return function() {
if (--tick >= 0) {
window.setTimeout(internalCallback, ++counter * factor);
callback();
}
}
}(times, 0);
window.setTimeout(internalCallback, factor);
};
// console.log() requires firebug
setDeceleratingTimeout(function(){ console.log('hi'); }, 10, 10);
setDeceleratingTimeout(function(){ console.log('bye'); }, 100, 10);
I like this question - inspired a little timer object in me:
window.setVariableInterval = function(callbackFunc, timing) {
var variableInterval = {
interval: timing,
callback: callbackFunc,
stopped: false,
runLoop: function() {
if (variableInterval.stopped) return;
var result = variableInterval.callback.call(variableInterval);
if (typeof result == 'number')
{
if (result === 0) return;
variableInterval.interval = result;
}
variableInterval.loop();
},
stop: function() {
this.stopped = true;
window.clearTimeout(this.timeout);
},
start: function() {
this.stopped = false;
return this.loop();
},
loop: function() {
this.timeout = window.setTimeout(this.runLoop, this.interval);
return this;
}
};
return variableInterval.start();
};
Example use
var vi = setVariableInterval(function() {
// this is the variableInterval - so we can change/get the interval here:
var interval = this.interval;
// print it for the hell of it
console.log(interval);
// we can stop ourselves.
if (interval>4000) this.stop();
// we could return a new interval after doing something
return interval + 100;
}, 100);
// we can change the interval down here too
setTimeout(function() {
vi.interval = 3500;
}, 1000);
// or tell it to start back up in a minute
setTimeout(function() {
vi.interval = 100;
vi.start();
}, 60000);
I had the same question as the original poster, did this as a solution. Not sure how efficient this is ....
let interval = 5000; // initial condition
let run = setInterval(request, interval); // start setInterval as "run"
function request() {
console.log(interval); // firebug or chrome log
clearInterval(run); // stop the setInterval()
// dynamically change the run interval
if (interval > 200) {
interval = interval * .8;
} else {
interval = interval * 1.2;
}
run = setInterval(request, interval); // start the setInterval()
}
This is my way of doing this, i use setTimeout:
var timer = {
running: false,
iv: 5000,
timeout: false,
cb : function(){},
start : function(cb,iv){
var elm = this;
clearInterval(this.timeout);
this.running = true;
if(cb) this.cb = cb;
if(iv) this.iv = iv;
this.timeout = setTimeout(function(){elm.execute(elm)}, this.iv);
},
execute : function(e){
if(!e.running) return false;
e.cb();
e.start();
},
stop : function(){
this.running = false;
},
set_interval : function(iv){
clearInterval(this.timeout);
this.start(false, iv);
}
};
Usage:
timer.start(function(){
console.debug('go');
}, 2000);
timer.set_interval(500);
timer.stop();
A much simpler way would be to have an if statement in the refreshed function and a control to execute your command at regular time intervals . In the following example, I run an alert every 2 seconds and the interval (intrv) can be changed dynamically...
var i=1;
var intrv=2; // << control this variable
var refreshId = setInterval(function() {
if(!(i%intrv)) {
alert('run!');
}
i++;
}, 1000);
This can be initiated however you want. timeout is the method i used to keep it on the top of the hour.
I had the need for every hour to begin a code block on the hour. So this would start at server startup and run the interval hourly. Basicaly the initial run is to begin the interval within the same minute. So in a second from init, run immediately then on every 5 seconds.
var interval = 1000;
var timing =function(){
var timer = setInterval(function(){
console.log(interval);
if(interval == 1000){ /*interval you dont want anymore or increment/decrement */
interval = 3600000; /* Increment you do want for timer */
clearInterval(timer);
timing();
}
},interval);
}
timing();
Alternately if you wanted to just have something happen at start and then forever at a specific interval you could just call it at the same time as the setInterval. For example:
var this = function(){
//do
}
setInterval(function(){
this()
},3600000)
this()
Here we have this run the first time and then every hour.
I couldn't synchronize and change the speed my setIntervals too and I was about to post a question. But I think I've found a way. It should certainly be improved because I'm a beginner. So, I'd gladly read your comments/remarks about this.
<body onload="foo()">
<div id="count1">0</div>
<div id="count2">2nd counter is stopped</div>
<button onclick="speed0()">pause</button>
<button onclick="speedx(1)">normal speed</button>
<button onclick="speedx(2)">speed x2</button>
<button onclick="speedx(4)">speed x4</button>
<button onclick="startTimer2()">Start second timer</button>
</body>
<script>
var count1 = 0,
count2 = 0,
greenlight = new Boolean(0), //blocks 2nd counter
speed = 1000, //1second
countingSpeed;
function foo(){
countingSpeed = setInterval(function(){
counter1();
counter2();
},speed);
}
function counter1(){
count1++;
document.getElementById("count1").innerHTML=count1;
}
function counter2(){
if (greenlight != false) {
count2++;
document.getElementById("count2").innerHTML=count2;
}
}
function startTimer2(){
//while the button hasn't been clicked, greenlight boolean is false
//thus, the 2nd timer is blocked
greenlight = true;
counter2();
//counter2() is greenlighted
}
//these functions modify the speed of the counters
function speed0(){
clearInterval(countingSpeed);
}
function speedx(a){
clearInterval(countingSpeed);
speed=1000/a;
foo();
}
</script>
If you want the counters to begin to increase once the page is loaded, put counter1() and counter2() in foo() before countingSpeed is called. Otherwise, it takes speed milliseconds before execution.
EDIT : Shorter answer.
(function variableInterval() {
//whatever needs to be done
interval *= 2; //deal with your interval
setTimeout(variableInterval, interval);
//whatever needs to be done
})();
can't get any shorter
Here is yet another way to create a decelerating/accelerating interval timer. The interval gets multiplied by a factor until a total time is exceeded.
function setChangingInterval(callback, startInterval, factor, totalTime) {
let remainingTime = totalTime;
let interval = startInterval;
const internalTimer = () => {
remainingTime -= interval ;
interval *= factor;
if (remainingTime >= 0) {
setTimeout(internalTimer, interval);
callback();
}
};
internalTimer();
}
Make new function:
// set Time interval
$("3000,18000").Multitimeout();
jQuery.fn.extend({
Multitimeout: function () {
var res = this.selector.split(",");
$.each(res, function (index, val) { setTimeout(function () {
//...Call function
temp();
}, val); });
return true;
}
});
function temp()
{
alert();
}
This piece of code below accelerates (acceleration > 1) or decelerates (acceleration <1) a setInterval function :
function accelerate(yourfunction, timer, refresh, acceleration) {
var new_timer = timer / acceleration;
var refresh_init = refresh;//save this user defined value
if (refresh < new_timer ){//avoid reseting the interval before it has produced anything.
refresh = new_timer + 1 ;
};
var lastInter = setInterval(yourfunction, new_timer);
console.log("timer:", new_timer);
function stopLastInter() {
clearInterval(lastInter);
accelerate(yourfunction, new_timer, refresh_init, acceleration);
console.log("refresh:", refresh);
};
setTimeout(stopLastInter, refresh);
}
With :
timer: the setInterval initial value in ms (increasing or decreasing)
refresh: the time before a new value of timer is calculated. This is the step lenght
acceleration: the gap between the old and the next timer value. This is the step height
Inspired by the internal callback above, i made a function to fire a callback at fractions of minutes. If timeout is set to intervals like 6 000, 15 000, 30 000, 60 000 it will continuously adapt the intervals in sync to the exact transition to the next minute of your system clock.
//Interval timer to trigger on even minute intervals
function setIntervalSynced(callback, intervalMs) {
//Calculate time to next modulus timer event
var betterInterval = function () {
var d = new Date();
var millis = (d.getMinutes() * 60 + d.getSeconds()) * 1000 + d.getMilliseconds();
return intervalMs - millis % intervalMs;
};
//Internal callback
var internalCallback = function () {
return function () {
setTimeout(internalCallback, betterInterval());
callback();
}
}();
//Initial call to start internal callback
setTimeout(internalCallback, betterInterval());
};
This is my idea for times when you do not want loops like setInterval to overlap.
You also want to be able to set the loop execution delay and start and stop the loop, instansly on the fly.
I am using a loop_flag variable and a setTimeout function.
I set the main function to async so that you can call other functions in the body by calling await. When the main body of your code is running, the main loop waits and does not repeat itself. (which is not the case with setInterval)
An example of a simple code is:
//#NabiKAZ
document.getElementById("btn_start").addEventListener("click", function() {
console.log("Starting...");
loop_flag = true;
loop_func();
});
document.getElementById("btn_stop").addEventListener("click", function() {
console.log("Stoping...");
loop_flag = false;
});
var n = 0;
var loop_flag = false;
var loop_func = async function() {
if (!loop_flag) {
console.log("STOP.");
return;
}
//body main function inhere
n++;
console.log(n);
////
if (loop_flag) {
setTimeout(loop_func, document.getElementById("inp_delay").value);
} else {
console.log("STOP.");
}
}
<input id="inp_delay" value="1000">
<button id="btn_start">START</button>
<button id="btn_stop">STOP</button>
For a more complete code with a fetch request inside the loop, see here:
https://jsfiddle.net/NabiKAZ/a5hdw2bo/
You can use a variable and change the variable instead.
setInterval(() => function, variable)
You can do this by clearing the interval every iteration, changing the timer value and setting the interval again. Hope it helps ;)
For exemple:
const DOMCounter = document.querySelector(".counter")
let timer = 1000
const changeCounter = () => {
clearInterval(interval)
DOMCounter.innerHTML = timer
timer += 1000
timer == 5000 && timer == 1000
interval = setInterval(changeCounter, timer)
}
let interval = setInterval(changeCounter, timer)
<div class="container">
<p class="counter"></p>
</div>
var counter = 15;
var interval = function() {
setTimeout(function(){
// Write your code here and remove console.log, remember that you need declare yourDynamicValue and give it a value
console.log((new Date()).getTime())
window.counter = yourDynamicValue;
window.interval();
}, counter);
}
// It needs to run just once as init
interval();