I need to trigger a document.onload kinda event, but I want it to be triggered just when the HTML is completely loaded, without waiting for images or other elements.
I've been looking arround but I can't find something like that. Is there any way to do it?
Thanks!
You could just put a <script> tag with your code right at the bottom just before your </body> with the code to execute.
There's nothing to guarentee that images won't be loaded. But it certainly won't wait until they are loaded before it runs.
Use the DOMContentLoaded event:
https://developer.mozilla.org/en-US/docs/DOM/Mozilla_event_reference/DOMContentLoaded
The DOMContentLoaded event is fired when the document has been completely loaded and parsed, without waiting for stylesheets, images, and subframes to finish loading (the load event can be used to detect a fully-loaded page).
(and just for the heck of it, but with jQuery: $(document).ready(function () {});)
I don't remember a specific event for that, but you can trigger your event by putting this just before your last closing html tag:
...
<script type="text/javascript">
html_loaded(); // Custom function call
</script>
</html>
That should work very effectively for any purpose.
HTH
Francisco
The DOMContentLoaded event proposed by #Ian would work, but it is in the HTML5 specification and therefore would not be supported by legacy browsers like IE8.
Other wise I think #Chris Farmiloe's script solution is the best way to go.
Related
I know that we can use defer async and no attribute which results in different ways of loading a script. But I want to know how does window.load event fit into the picture?
I noticed that it waits for the async scrips too. But since scripts can dynamically load new scripts, how window.load event decides when to stop?
"The end" section of HTML Living Standard is what you're looking for I guess.
How do I run a Javascript function when the content of an <object> has been loaded? The DOMContentLoaded event fires before that, and things that rely on it like JQuery's $() likewise.
Compare this to this. The first example fails because the function is executed when the external SVG hasn't been loaded. The second example polls for the elements it wants to change and only then executes the relevant code, and succeeds.
Polling works in practice, but is there a better solution for this? Ideally there would be an event fired that I can use.
Does using the onload DomEvent work?
<object onload="changeColor()" data="circles.svg" type="image/svg+xml" id="circles"></object>
see my it here
You should use onload/ready event of jquery - http://api.jquery.com/ready/
$('#circles').ready(function(){
changeColor();
});`
I lately saw some sites which uses this pattern :
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script>
$(function (){...do some stuff with plugins...});
</script>
</head>
<body>
<script src="myplugin1.js"></script>
<script src="myplugin2.js"></script>
<script src="myplugin3.js"></script>
</body>
</html>
This made me think of some traps :
Question #1
document.ready event is raised not executed after the plugins(JS) has been parsed.
it is executed when the dom structure is done. (notice: I didn't say :"when all resources has been downloaded" !)
So there could be a situation where the document. readyfunction will try to use a plugin variable which hasn't been fully downloaded. (which will cause error).
Am I right ?
Question #2
This leads me to : "never use document.ready" before the script references location ( I mean : in situations where document.ready is dependent on those script variables).
Am I right ?
p.s. Im not talking about window.load which will obviously will work here but i'll have to wait much longer.
If you think about all the kinds of resources in a page, many can be loaded separately from the page content: images and stylesheets, for example. They may change the look of the page, but they can't really change the structure, so it's safe to load them separately.
Scripts, on the other hand, have this little thing called document.write that can throw a wrench into the works. If I have some HTML like this:
Who would <script>document.write("<em>");</script>ever</em> write like this?
Then browsers will parse it just fine; document.write, if used at the top level like that, effectively inserts HTML at that position to be parsed. That means that the whole rest of the page depends upon a script element, so the browser can't really move on with the document until that script has loaded.
Because scripts can potentially modify the HTML and change the structure, the browser can't wait to load them later: it has to load them at that moment, and it can't say the DOM is ready yet because a script might modify it. Therefore, the browser must delay the DOM ready event until all the scripts have run. This makes it safe for you to put the dependent code at the top in a ready handler.
However, I'd recommend you don't, because it's not very clear.
The event that $(document).ready equates to is DOMContentLoaded in modern browsers (and it falls back to some others in legacy browsers that equate to the same scenario).
MDN summarizes it pretty nicely:
The DOMContentLoaded event is fired when the document has been
completely loaded and parsed, without waiting for stylesheets, images,
and subframes to finish loading (the load event can be used to detect
a fully-loaded page).
So your scripts will always be parsed by the time it is executed.
Recently I saw that you could use either
$('document').ready(function() {
//Do Code
});
or
$('window').load(function() {
//Do Code
});
for jQuery.
However, they seem the same to me! But clearly aren't.
So my question is: Which one should I use for a website sort of based on animation and async? And also which one of the two is generally better to use?
Thanks.
$('document').ready runs the code when the DOM is ready, but not when the page itself has loaded, that is, the site has not been painted and content like images have not been loaded.
$(window).load runs the code when the page has been painted and all content has been loaded. This can be helpful when you need to get the size of an image. If the image has no style or width/height, you can't get its size unless you use $(window).load.
Well first of all you may want to consider using the "ready" event, which you can handler like this:
$().ready(function() {
...
});
Or, more succinctly and idiomatically:
$(function() {
...
});
The "load" handler really relates to an actual event, and can be handled on several different sorts of elements: <img> and <iframe> for example. The "load" event at the document or window level happens when all of the page's resources are loaded. The (synthesized, in some browsers) "ready" event however happens when the page DOM is ready but possibly before things like <img> contents.
Another option is to simply put your <script> tags at the very end of the <body> or even after the <body>. That way the scripts have the entire DOM to work with, but you don't have to worry about any sort of event handling to know that.
I have been having a problem lately with my JavaScript CODE and taking a portion of my code out of my $(document).ready() and putting it within $(window).load() fixed the problem.
Now I understand that window.load is fired just after document.ready, but why is it not ready after document.ready, that is after window.load()?
load is called when all assets are done loading, including images. ready is fired when the DOM is ready for interaction.
From the MDC, window.onload:
The load event fires at the end of the
document loading process. At this
point, all of the objects in the
document are in the DOM, and all the
images and sub-frames have finished
loading.
From the jQuery API documentation, .ready( handler ):
While JavaScript provides the load
event for executing code when a page
is rendered, this event does not get
triggered until all assets such as
images have been completely received.
In most cases, the script can be run
as soon as the DOM hierarchy has been
fully constructed. The handler passed
to .ready() is guaranteed to be
executed after the DOM is ready, so
this is usually the best place to
attach all other event handlers and
run other jQuery code. When using
scripts that rely on the value of CSS
style properties, it's important to
reference external stylesheets or
embed style elements before
referencing the scripts.
$(document).ready() means that the DOM of your page is ready to be manipulated.
window.load() is triggered when the whole page (incl. components like CSS and image files) has been completely loaded.
What are you trying to achieve?
$(document).ready(function(){
//code here
});
The code above is used almost every time when we work with jQuery.
This code is used when we want to initialize our jQuery codes after the DOM is ready.
$(window).load()
Sometimes you want to manipulate pictures. For example you want to vertically and horizontally align a picture and you need to get the width and height of the picture in order to do that. With $(document).ready() you won’t be able to do that if the visitor doesn’t have the image already loaded, in which case you need to initialize the jquery alignment function when the image finishes loading. That’s where we use $(window).load()
$(document).ready is jQuery event that is fired when DOM is loaded, so it’s fired when the document structure is ready.
$(window).load event is fired after whole content (including css, images etc..) is loaded.
This is major difference.
$(document).ready() is wrap DOM in <body>...</body>
$(window).load() is papa of document wrap all DOM in <html>...</html>
Let's use in your case to save render processing.
In simple words, window.load is called when all content of window is loaded whereas document.ready is called when DOM is loaded and document structure is ready.
Load state is the state when the window object has been created and all necessary components including DOM has been loaded in memory, but has not been passed to the rendering engine for rendering the same in page.
Ready state on the other hand makes it sure that the DOM elements, events and other dependent components are passed on to the rendering engine, rendered on page, and is ready for interaction and manipulation.
$(document).ready is slider fast in comparison $(window).load Event.
$(document).ready is fire when Dom is load but $(window).load Event
fire when Dom ,css and images fully loaded.
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<script src="https://code.jquery.com/jquery-1.12.4.js" ></script>
<script>
$(window).load(function () {
var img = $('#img1');
alert( "Image Height = " + img.height() + "<br>Image Width = " + img.width());
});
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<img id="img1" src="https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTozkxoNSH8739juRXJJX5JxREAB6I30bFyexPoCdRVa2fKfH2d" />
</div>
</form>
</body>
</html>
$(document).ready is a jQuery event. It fires as soon as the DOM is loaded and ready to be manipulated by script. This is the earliest point in the page load process where the script can safely access elements in the page's html DOM. This event is fired before all the images, css etc. are fully loaded.
window.load() is triggered when the whole page (incl. components like CSS and image files) has been completely loaded.