Question

How would I convert the following:

while True:
    # do something
    time.sleep(2)

into JavaScript?

Answer 1

You would not, as JavaScript does not sleep – it is synchronous and event-based. Yet, you can schedule functions to be executed later in time via setTimeout and setInterval:

var timerid = setInterval(function() {
    // do something
    // instead of "break", you'd use "clearTimeout(timerid)"
}, 2000);

---

For your ajax progress bar, I’d recommend the following which does not fire requests strictly each 2s, but waits for them to return:

function getUpdate() {
    myAjax(…, function onAjaxSuccess(result) { // an async event as well
        // show(result)
        if (!result.end)
            setTimeout(getUpdate, 2000);
    });
}
getUpdate();