Why is this function not working?

Question

I had this code:

var frames = document.getElementsByTagName("iFrame");
var auto_resize_timer = window.setInterval("autoresize_frames()", 400);
function autoresize_frames() {
 for (var i = 0; i < frames.length; ++i) {
 if (frames[i].contentWindow.document.body) {
 var frames_size = frames[i].contentWindow.document.body.offsetHeight;
 if (document.all && !window.opera) {
 frames_size = frames[i].contentWindow.document.body.scrollHeight;
 }
 frames[i].style.height = frames_size + 'px';
 }
 }
}

That was working fine.

Then, I decided to put it in its own module:

function autoResizeFrames() {
 var frames = document.getElementsByTagName("iFrame");
 window.setInterval("autoresize_frames(frames)", 400);
}
function autoresize_frames(frames) {
 for (var i = 0; i < frames.length; ++i) {
 if (frames[i].contentWindow.document.body) {
 var frames_size = frames[i].contentWindow.document.body.offsetHeight;
 if (document.all && !window.opera) {
 frames_size = frames[i].contentWindow.document.body.scrollHeight;
 }
 frames[i].style.height = frames_size + 'px';
 }
 }
}

And run it in the page like so:

<script type="text/javascript">
 $(document).ready
(
 function () {
 autoResizeFrames();
 }
 );
</script>

But now it does not work? Any ideas why?

Thanks

• graphicdivine: "does not work" how exactly?

Answer 1

When you run:

 window.setInterval("autoresize_frames(frames)", 400);

You are essentially evaling your code in the context of the window. When using setInterval, you should pass a reference to the function instead of a string. You can read why eval is bad at Why is using the JavaScript eval function a bad idea?

Normally you would do:

 window.setInterval(autoresize_frames, 400);

However if your function takes arguments then you will need to wrap it in a function.

The following will work:

window.setInterval(function() {
 autoresize_frames(frames);
}, 400);

Answer 2

In your own function, "frames" is declared internally. You could try removing the "var" keyword so it becomes a global variable.

• Gazler: I wouldn't advise polluting the global namespace as the solution. Please see stackoverflow.com/questions/39691/javascript-best-practices/…

Answer 3

I think the problem might on frames variable which might not be accessible inside setInterval. You can try this

function autoResizeFrames() {
 window.setInterval(function(){
 autoresize_frames(document.getElementsByTagName("iFrame"))
 }, 400);
}