setInterval stops without any reason when browser tab is background

Question

I am working on an application that sends current timestamp to database every 2 minutes with AJAX using setInterval.

But somehow setInterval stops after some minutes (i didnt calculate the exact time), but i believe it happens when i dont open that browser's tab for 20-30 minutes.

function tmstmp() {
$.post("send_functions.php?act=time");
}

$(function() { 
setInterval(tmstmp, 60000);
});

Is that normal that setInterval stops if that tab is not on foreground ?

If yes, how can i prevent setInterval to stop ? or check if it stopped ?

Thanks

See this question: http://stackoverflow.com/questions/6951727/setinterval-not-working-properly-on-chrome — , Apr 15 '12 at 20:21
Check my edited answer. Should at least give you a clue if the interval works. — brezanac, Apr 15 '12 at 20:27
BTW, why would you want to send timestamps to your web server? I am sure that there is a way for your web server to acquire the exact timestamp data you are trying to send it with every POST request. — brezanac, Apr 15 '12 at 20:43
i am sending it to mysql to "last_access" row to check if user still online. — Utku Dalmaz, Apr 15 '12 at 20:44
@gdoron: Very true. Of course there's no rep for comments, so I'm fine with that... for now. — , Apr 15 '12 at 20:44
@amnotiam. You gave me an idea for a new question in `Meta` LOL... — gdoron is supporting Monica, Apr 15 '12 at 20:47
This might be a more useful example to work with (with how I would do it with `setTimeout()` instead): http://jsfiddle.net/kxa53/ — Jared Farrish, Apr 15 '12 at 21:07

score 1 · Answer 1 · edited Jan 24 '20 at 19:31

1

You should try to make an function call on page startup:

test();

and then loop that function:

function test() {
    setTimeout(function() {
        // your code
        test();
    }, 2000);
}

edited Jan 24 '20 at 19:31

jaycer

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answered Aug 14 '16 at 16:01

Jakub

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1

brezanac · Answer 2 · 2012-04-15T20:30:07.223

0

No code + no debug information = hard to tell what went wrong.

Just to be sure add the following line to the code (method) that gets executed with setInterval and watch after 20-30 minutes if you still get output in the console.

console.log('Yep! I am alive!');

EDIT: Could be anything but try changing the tmstmp method to include a callback function after the POST request gets executed. That way you'll at least know that it works.

function tmstmp() {
    $.post("send_functions.php?act=time", function(data){
        console.log('Yep! I am alive!');
    });
}

edited Apr 15 '12 at 20:30

answered Apr 15 '12 at 20:17

brezanac

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Well... If you had the code, would you spend the time debugging it- meaning wait couple of times 20-30 minutes? **:)** – gdoron is supporting Monica Apr 15 '12 at 20:21
@gdoron just change the interval time to a few seconds while you're debugging. – jbabey Apr 15 '12 at 20:31
will try and write here thx. by the way should i use setTimeout with repeated function ? is it better than setInterval ? – Utku Dalmaz Apr 15 '12 at 20:33
Generally `setTimeout()` has proven to be much more reliable than `setInterval()`. – brezanac Apr 15 '12 at 20:37
1

@holodoc - I prefer `setTimeout()` to `setInterval()` in many cases where they may both work, but with a 60 second interval, I don't know the statement that one is more or less reliable is accurate. – Jared Farrish Apr 15 '12 at 21:21

score 0 · Answer 3 · answered Apr 15 '12 at 20:21

0

That's not supposed to happen. Browsers may indeed reduce the timer resolution to something around 1/s, but not clear the setInterval.

Could there be some bug in your code that causes a clearInterval?

answered Apr 15 '12 at 20:21

user123444555621

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no there is no bug as i added to code here. when i did search on google i saw that many ppl face this issue. – Utku Dalmaz Apr 15 '12 at 20:23
Hm, I never heard of that issue. Can you cite some sources? – user123444555621 Apr 15 '12 at 20:35
for example http://stackoverflow.com/questions/2203304/setinterval-stops-after-ajax-request – Utku Dalmaz Apr 15 '12 at 20:37

setInterval stops without any reason when browser tab is background

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