javascript - setTimeout inside while loop

Question

I've searched for how to use setTimeOut with for loops, but there isn't a lot on how to use it with while loops, and I don't see why there should be much difference anyway. I've written a few variations of the following code, but this loop seems to crash the browser:

while(src == '')
{ 
    (function(){
        setTimeout(function(){
        src = $('#currentImage').val();
        $("#img_"+imgIdx).attr('src',src);
        }, 500);
     });
} 

Why?

Basically I have an image created dynamically whose source attribute takes time to load at times, so before I can display it, I need to keep checking whether it's loaded or not, and only when its path is available in $('#currentImage'), then do I display it.

This code worked fine before I used a while loop, and when I directly did

setTimeout(function(){
    src = $('#currentImage').val();
    $("#img_"+imgIdx).attr('src',src);
}, 3000);

But I don't want to have to make the user wait 3 seconds if the loading might be done faster, hence I put the setTimeOut in a while loop and shorted its interval, so that I only check for the loaded path every half second. What's wrong with that?

Answer 1

The while loop is creating trouble, like jrdn is pointing out. Perhaps you can combine both the setInterval and setTimeout and once the src is filled, clear the interval. I placed some sample code here to help, but am not sure if it completely fits your goal:

    var src = '';
    var intervalId = window.setInterval(
        function () {

            if (src == '') {
                setTimeout(function () {
                    //src = $('#currentImage').val();
                    //$("#img_" + imgIdx).attr('src', src);
                    src = 'filled';
                    console.log('Changing source...');
                    clearInterval(intervalId);
                }, 500);
            }
            console.log('on interval...');
        }, 100);

    console.log('stopped checking.');

Hope this helps.