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Page elements are still loading after window.on('load', function() {}) is finished?

I want to hide a spinner div once ALL elements are loaded and in position on my page. I put a fadeOut() function on my spinner div in the window.on('load', ..., but I can see the tab/page is still loading even though the elements/assets are not in the correct css position yet. How do I force the spinner div to remain until everything is in place, i.e. until the loading icon on the tab is finished spinning?
This is my code:
$(window).load(function() {
$('#spinner').fadeOut();
}
jQuery(document).ready(function($){
// Append the spinner div.
$("#spinner").append(spinner.el);
}

It sounds like you have a large volume of CSS and it is taking a long time for the browser to compute the style for each element after all content for the page has loaded. You could do some experiments using your timeout idea, and polling one or more elements on the page to see when the computed style matches the expected style. The last element to be assigned a computed style might vary at each page load, and/or by browser, so you would definitely need to test your method. The example below uses some information from the accepted answer here to poll an element for an expected style.
var expectedTop="5px";
function ready() {
$('#spinner').fadeOut();
}
function poll() {
var o = document.getElementById("pollElementId");
var comp = o.currentStyle || getComputedStyle(o,null);
if(comp.top==expectedTop) {
ready();
}
else {
setTimeout("poll()",500);
}
}
jQuery(document).ready(function($){
$("#spinner").append(spinner.el);
poll();
}
Here pollElementId is the id of an element in the DOM that we are positioning via CSS.

force DOM redraw with javascript on demand

The title of the question expresses what I think is the ultimate question behind my particular case.
My case:
Inside a click handler, I want to make an image visible (a 'loading' animation) right before a busy function starts. Then I want to make it invisible again after the function has completed.
Instead of what I expected I realize that the image never becomes visible. I guess that this is due to the browser waiting for the handler to end, before it can do any redrawing (I am sure there are good performance reasons for that).
The code (also in this fiddle: http://jsfiddle.net/JLmh4/2/)
html:
<img id="kitty" src="http://placekitten.com/50/50" style="display:none">
<div>click to see the cat </div>
js:
$(document).ready(function(){
$('#enlace').click(function(){
var kitty = $('#kitty');
kitty.css('display','block');
// see: http://unixpapa.com/js/sleep.html
function sleepStupidly(usec)
{
var endtime= new Date().getTime() + usec;
while (new Date().getTime() < endtime)
;
}
// simulates bussy proccess, calling some function...
sleepStupidly(4000);
// when this triggers the img style do refresh!
// but not before
alert('now you do see it');
kitty.css('display','none');
});
});
I have added the alert call right after the sleepStupidly function to show that in that moment of rest, the browser does redraw, but not before. I innocently expected it to redraw right after setting the 'display' to 'block';
For the record, I have also tried appending html tags, or swapping css classes, instead of the image showing and hiding in this code. Same result.
After all my research I think that what I would need is the ability to force the browser to redraw and stop every other thing until then.
Is it possible? Is it possible in a crossbrowser way? Some plugin I wasn't able to find maybe...?
I thought that maybe something like 'jquery css callback' (as in this question: In JQuery, Is it possible to get callback function after setting new css rule?) would do the trick ... but that doesn't exist.
I have also tried to separte the showing, function call and hiding in different handlers for the same event ... but nothing. Also adding a setTimeout to delay the execution of the function (as recommended here: Force DOM refresh in JavaScript).
Thanks and I hope it also helps others.
javier
EDIT (after setting my preferred answer):
Just to further explain why I selected the window.setTimeout strategy.
In my real use case I have realized that in order to give the browser time enough to redraw the page, I had to give it about 1000 milliseconds (much more than the 50 for the fiddle example). This I believe is due to a deeper DOM tree (in fact, unnecessarily deep).
The setTimeout let approach lets you do that.

Use JQuery show and hide callbacks (or other way to display something like fadeIn/fadeOut).
http://jsfiddle.net/JLmh4/3/
$(document).ready(function () {
$('#enlace').click(function () {
var kitty = $('#kitty');
// see: http://unixpapa.com/js/sleep.html
function sleepStupidly(usec) {
var endtime = new Date().getTime() + usec;
while (new Date().getTime() < endtime);
}
kitty.show(function () {
// simulates bussy proccess, calling some function...
sleepStupidly(4000);
// when this triggers the img style do refresh!
// but not before
alert('now you do see it');
kitty.hide();
});
});
});

Use window.setTimeout() with some short unnoticeable delay to run slow function:
$(document).ready(function() {
$('#enlace').click(function() {
showImage();
window.setTimeout(function() {
sleepStupidly(4000);
alert('now you do see it');
hideImage();
}, 50);
});
});
Live demo

To force redraw, you can use offsetHeight or getComputedStyle().
var foo = window.getComputedStyle(el, null);
or
var bar = el.offsetHeight;
"el" being a DOM element

I do not know if this works in your case (as I have not tested it), but when manipulating CSS with JavaScript/jQuery it is sometimes necessary to force redrawing of a specific element to make changes take effect.
This is done by simply requesting a CSS property.
In your case, I would try putting a kitty.position().left; before the function call prior to messing with setTimeout.

What worked for me is setting the following:
$(element).css('display','none');
After that you can do whatever you want, and eventually you want to do:
$(element).css('display','block');

Have a function change the DOM while in the function

I'm using an application that does two steps during a jquery click event.
1. Changes the CSS properties of an element with a sprite and color attribute
2. Runs a function that iterates scanning the page.
Is it possible to have the page make the css changes and show it in the browser, then run the iteration?
The css changes are made by adding classes and removing classes to the elements.
onBtn.click(function(event){
if(clicked['mon'] == 0){
monBtn.attr("class", "active");
clicked['mon'] = 1;
dow['mon'] = 1;
}
else {
monBtn.removeClass("active");
clicked['mon'] = 0;
dow['mon'] = 0;
}
checkIfButtonsAreClicked();
});

If you're looking for the screen to update before running some other code, you could set the code to fire in 0ms:
makeCSSChanges();
setTimeout(function () {
// The browser will only run this callback once it's taken a breath and
// done its usual behind-the-scenes stuff.
scanThePage();
}, 0);
When a timeout is set for 0ms, most browsers will do their usual behavior (redraw the page, go about their business, etc.), then take care of scheduled events.
In most cases, though, the delay wouldn't be noticeable enough to matter. If the delay is significant, then we're approaching the kind of delay that can also lag out the whole browser. Careful.

hide() vs hide("slow")

I need to hide a div and, with this code it works fine:
var idObj = $(this).attr('key');
var valH = $(this).attr('hideval');
var valS = $(this).attr('showval');
if ($('div[name='+idObj+']').attr('isdisplay') == 'no') {
$('div[name='+idObj+']').children().show("slow");
$('div[name='+idObj+']').attr('isdisplay','yes');
var divTitle = $('div[name='+idObj+']').children().first();
var divArrow = $(this).children().first();
//.attr('src',prefixImg+valH);
//divTitle.show();
//divArrow.show();
$(this).children().first().attr('src',prefixImg+valH);
} else {
var divTitle = $('div[name='+idObj+']').children().first();
var divArrow = $('div[name='+idObj+']').children().last();
//.attr('src',prefixImg+valS);
$('div[name='+idObj+']').children().hide();
$('div[name='+idObj+']').attr('isdisplay','no');
divTitle.show();
divArrow.show();
$(this).children().first().attr('src',prefixImg+valS);
}
My div is hidden and the Title and arrows to reopen the div are shown. But if I try to use hide("slow") the divTitle and divArrow don't appear when my div is closed. Same problem using hide(1000).
Is there a difference between hide with and without "slow" parameter?
thanks,
Andrea

From the official site
The matched elements will be hidden immediately, with no animation. This is roughly equivalent to calling .css('display', 'none'), except that the value of the display property is saved in jQuery's data cache so that display can later be restored to its initial value. If an element has a display value of inline, then is hidden and shown, it will once again be displayed inline.
When a duration is provided, .hide() becomes an animation method. The .hide() method animates the width, height, and opacity of the matched elements simultaneously. When these properties reach 0, the display style property is set to none to ensure that the element no longer affects the layout of the page.
So, if hide is used without delay, it hides immediately without animating - eg, poof.
If it's used with time, it becomes animated, so it disapears over time.
For your problems, it is difficult to judge without the corresponding html code.

$(element).hide() hides an element instantly, where $(element).hide('slow') will animate its disappearance (slowly).
It looks like (though I'm not sure) you want to do stuff after the animation is finished. In that case, do something like this:
var that = this; // here to preserve scope for the block below
$('div[name='+idObj+']').children().hide('slow', function() {
// This stuff happens after the hide animation is done.
$('div[name='+idObj+']').attr('isdisplay','no');
divTitle.show();
divArrow.show();
$(that).children().first().attr('src',prefixImg+valS); // <= note "that" instead of "this"
});

According to the jQuery documentation
The strings 'fast' and 'slow' can be supplied to indicate durations of
200 and 600 milliseconds, respectively.
Also duration in milliseconds can be supplied to it..

Forcing a DOM refresh in Internet explorer after javascript dom manipulation

Here is the situation. I have some javascript that looks like this:
function onSubmit() {
doSomeStuff();
someSpan.style.display="block";
otherSpan.style.display="none";
return doLongRunningOperation;
}
When I make this a form submit action, and run it from a non IE browser, it quickly swaps the two spans visibility and run the long javascript operation. If I do this in IE it does not do the swap until after onSubmit() completely returns.
I can force a dom redraw by sticking an alert box in like so:
function onSubmit() {
doSomeStuff();
someSpan.style.display="block";
otherSpan.style.display="none";
alert("refresh forced");
return doLongRunningOperation;
}
Also, the obvious jquery refactoring does not affect the IE behavior:
function onSubmit() {
doSomeStuff();
$("#someSpan").show();
$("#otherSpan").hide();
return doLongRunningOperation;
}
This behavior exists on IE8 and IE6. Is there anyway to force a redraw of the DOM in these browsers?

Mozilla (maybe IE as well) will cache/delay executing changes to the DOM which affect display, so that it can calculate all the changes at once instead of repeatedly after each and every statement.
To force an update (to force an immediate, synchronous reflow or relayout), your javascript should read a property that's affected by the change, e.g. the location of someSpan and otherSpan.
(This Mozilla implementation detail is mentioned in the video Faster HTML and CSS: Layout Engine Internals for Web Developers.)

To continue what ChrisW says:
here's flushing script to flash DOM, so you don't have to call alert(""); (found at http://amolnw.wordpress.com/category/programming/javascript/):
function flushThis(id){
var msie = 'Microsoft Internet Explorer';
var tmp = 0;
var elementOnShow = document.getElementById(id);
if (navigator.appName == msie){
tmp = elementOnShow.parentNode.offsetTop + 'px';
}else{
tmp = elementOnShow.offsetTop;
}
}
It works for me!!!
Thanks for the tip.

I had this problem in Chrome 21 dragging a word that had a letter with a descender ('g'). It was leaving a trail of moth dust behind on the screen, which would vanish the next time something made the screen refresh. ChrisW's solution (interrogating a layout-sensitive property) didn't work.
What did work was to add a 1-pixel blank div at the top of the page, then remove it a millisecond later, by calling the following the function at the end of the drag operation:
// Needed by Chrome, as of Release 21. Triggers a screen refresh, removing drag garbage.
function cleanDisplay() {
var c = document.createElement('div');
c.innerHTML = 'x';
c.style.visibility = 'hidden';
c.style.height = '1px';
document.body.insertBefore(c, document.body.firstChild);
window.setTimeout(function() {document.body.removeChild(c)}, 1);
}
Note: You need the delay. Simply adding and removing the div doesn't work. Also, the div needs to be added above the part of the page that needs to be redrawn.

You can also wrap you longterm function in a setTimeout(function(){longTerm();},1);

Can your longRunningOperation be called asynchronously?

element.focus() works for me in IE10
function displayOnOff(){
var elm = document.getElementById("myDiv");
elm.style.display="block";
elm.focus();
for(var i=0; i<1000000; i++){
console.log("waiting...............");
}
elm.style.display = "none";
}