Question

I have a simple system that refreshes a div every few seconds:

$(document).ready(function() {
         $("#nownext").load("response.php");
       var refreshId = setInterval(function() {
          $("#nownext").load('response.php?randval='+ Math.random());
       }, 20000);
    });

Now, because of what the content is, it is more likely to update on the hour, or at half past. (Though not always). What I’d like to do it make the system refresh MORE often between a few minutes before and after the hour (and half past), just to make it more precise.

Is this possible/how would I do it without stressing out the client’s computer too much?

Answer 1

Since the interval itself is going to be dynamic, you’re going to have to use setTimeout instead.

Something like this (untested):

$(document).ready(function() {
    $("#nownext").load('response.php?randval='+ Math.random());
    var minutes = new Date().getMinutes(), interval = 60*10*1000; // default 10 mins
    if (minutes <= 10 || (minutes > 30 && minutes < 35) || minutes > 50) {
        // update once-per-minute if within the first/last 10mins of the hour, or 5mins within the half hour
        interval = 60*1000;
    }
    setTimeout(arguments.callee, interval);
});