Question

I have a javascript function that is called every 2000ms. I want to stop this so I can have the user do other things on the page without it being called again. Is this possible? Here is the function that gets called every 2000ms:

window.setInterval(function getScreen (sid) {
        if (window.XMLHttpRequest)
        {// code for IE7+, Firefox, Chrome, Opera, Safari
          xmlhttp=new XMLHttpRequest();
        }
        else
        {// code for IE6, IE5
          xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
        }
        xmlhttp.onreadystatechange=function()
        {
        if (xmlhttp.readyState==4 && xmlhttp.status==200)
          {
            document.getElementById("refresh").innerHTML=xmlhttp.responseText;
          }
        }
        xmlhttp.open("POST","getScreen.php?sid="+<?php echo $sid; ?>,true);
        xmlhttp.send();
    },2000);

Answer 1

There’s no built-in “pause” function, but you can stop it, and then start a new interval with the same function.

First, you need to capture the id returned by the call to setInterval:

let intervalId = window.setInterval(...);

Then when you want to stop it, call

 window.clearInterval(intervalId);

In your case I’d suggest defining setScreen by itself, and not inside of the call to setInterval. This way you can just use intervalId = window.setInterval(setScreen, 2000) when you want to resume it.