I have a simple script that create a span in the page with some info taken by flash player API.
I tried 3 ways:
1) If I put the script with no onload or with:
( function (){ ...code here... }) ();
This doesn't load all my code correctly, particularly the player info part:
var spanSound=document.createElement('span');
Fls_div.appendChild(spanSound);
spanSound.appendChild(document.createTextNode(" audioLev:")); // --OK--
var player = window.document.getElementById('movie_player');
var spanQual= document.createElement('span');
spanQual.appendChild(document.createTextNode("-->" + player.getPlaybackQuality() )); // --NO--
But all youtube's comments are loaded.
2) I put all the code into:
window.onload = function(){ ...code here... }
This does load all my code correctly, BUT it doesn't load the youtube's comments...
3) finally I tried:
window.addEventListener("load", function(e) { ...code here... }, false);
this loads all correct, code and comments.
Why these 3 different behaviours ( particularly the 2) )?
1 - The code runs before anything else is loaded. When you try things like document.getElementById, the elements don't exist yet, so your code won't find it.
2 - You're replacing the window.onload function. Looks like the page already has a onload function (that takes care of loading the comments..?) and when you asign another function to it, the first one will be replace and won't run anymore.
3 - You're adding an event listener. You can have multiple event listeners in a page, when the event happens, all of the event listeners will execute (compared to window.onload, where you can have only one function execute).
Related
I need to execute some JavaScript code when the page has fully loaded. This includes things like images.
I know you can check if the DOM is ready, but I don’t know if this is the same as when the page is fully loaded.
That's called load. It came waaaaay before DOM ready was around, and DOM ready was actually created for the exact reason that load waited on images.
window.addEventListener('load', function () {
alert("It's loaded!")
})
For completeness sake, you might also want to bind it to DOMContentLoaded, which is now widely supported
document.addEventListener("DOMContentLoaded", function(event){
// your code here
});
More info: https://developer.mozilla.org/en-US/docs/Web/Events/DOMContentLoaded
Usually you can use window.onload, but you may notice that recent browsers don't fire window.onload when you use the back/forward history buttons.
Some people suggest weird contortions to work around this problem, but really if you just make a window.onunload handler (even one that doesn't do anything), this caching behavior will be disabled in all browsers. The MDN documents this "feature" pretty well, but for some reason there are still people using setInterval and other weird hacks.
Some versions of Opera have a bug that can be worked around by adding the following somewhere in your page:
<script>history.navigationMode = 'compatible';</script>
If you're just trying to get a javascript function called once per-view (and not necessarily after the DOM is finished loading), you can do something like this:
<img src="javascript:location.href='javascript:yourFunction();';">
For example, I use this trick to preload a very large file into the cache on a loading screen:
<img src="bigfile"
onload="this.location.href='javascript:location.href=\'javascript:doredir();\';';doredir();">
Try this it Only Run After Entire Page Has Loaded
By Javascript
window.onload = function(){
// code goes here
};
By Jquery
$(window).bind("load", function() {
// code goes here
});
Try this code
document.onreadystatechange = function () {
if (document.readyState == "complete") {
initApplication();
}
}
visit https://developer.mozilla.org/en-US/docs/DOM/document.readyState for more details
Javascript using the onLoad() event, will wait for the page to be loaded before executing.
<body onload="somecode();" >
If you're using the jQuery framework's document ready function the code will load as soon as the DOM is loaded and before the page contents are loaded:
$(document).ready(function() {
// jQuery code goes here
});
the window.onload event will fire when everything is loaded, including images etc.
You would want to check the DOM ready status if you wanted your js code to execute as early as possible, but you still need to access DOM elements.
You may want to use window.onload, as the docs indicate that it's not fired until both the DOM is ready and ALL of the other assets in the page (images, etc.) are loaded.
In modern browsers with modern javascript (>= 2015) you can add type="module" to your script tag, and everything inside that script will execute after whole page loads. e.g:
<script type="module">
alert("runs after") // Whole page loads before this line execute
</script>
<script>
alert("runs before")
</script>
also older browsers will understand nomodule attribute. Something like this:
<script nomodule>
alert("tuns after")
</script>
For more information you can visit javascript.info.
And here's a way to do it with PrototypeJS:
Event.observe(window, 'load', function(event) {
// Do stuff
});
The onload property of the GlobalEventHandlers mixin is an event
handler for the load event of a Window, XMLHttpRequest, element,
etc., which fires when the resource has loaded.
So basically javascript already has onload method on window which get executed which page fully loaded including images...
You can do something:
var spinner = true;
window.onload = function() {
//whatever you like to do now, for example hide the spinner in this case
spinner = false;
};
Completing the answers from #Matchu and #abSiddique.
This:
window.addEventListener('load', (event) => {
console.log('page is fully loaded');
});
Is the same as this but using the onload event handler property:
window.onload = (event) => {
console.log('page is fully loaded');
};
Source:
https://developer.mozilla.org/en-US/docs/Web/API/Window/load_event
Live example here:
https://developer.mozilla.org/en-US/docs/Web/API/Window/load_event#live_example
If you need to use many onload use $(window).load instead (jQuery):
$(window).load(function() {
//code
});
2019 update: This is was the answer that worked for me. As I needed multiple ajax requests to fire and return data first to count the list items.
$(document).ajaxComplete(function(){
alert("Everything is ready now!");
});
I'm working to modify some content which is dynamically loaded via another script(let's call is script #1) onto my site. Script #1 loads some markup and content and I've been using the setTimeout() function to call my script (Script #2) using a delay of a few seconds, in order to wait to be sure that Script #1 has executed and the content is present in the DOM.
My issue is that Script#1 has different loading times, based on the server load and can be slow or fast depending on these factors, and right now, playing it safe with setTimeout() I'm often left with a second or two where my scripts are still waiting to be fired and Script #1 has already loaded the content.
How can I execute my script as soon as Script#1 successfully loads it's dynamic content?
I've found this post which does seem to address the same issue but using the setInterval function as #Matt Ball has laid out there doesn't work at all for some reason. I'm using the code below where 'div.enrollment' is meant to find in the DOM which is dynamically loaded and execute..
jQuery(window).load(function ($)
{
var i = setInterval(function ()
{
if ($('div.enrollment').length)
{
clearInterval(i);
// safe to execute your code here
console.log("It's Loaded");
}
}, 100);
});
Any help on guidance on this would be greatly appreciated! Thanks for your time.
It seems that the healcode.js is doing a lot of stuff. There is a whole lot of markup added to the <healcode-widget> tag.
I would try to add another tag with an id inside and test for its existence:
<healcode-widget ....><div id="healCodeLoading"></div></healcode-widget>
Test in an interval for the existence of healCodeLoading inside <healcode-widget>: (Assuming jQuery)
var healCodeLoadingInterval = setInterval(function(){
var healCodeLoading = jQuery('healcode-widget #healCodeLoading');
if (healCodeLoading.length == 0) {
clearInterval(healCodeLoadingInterval);
// Everything should be loaded now, so you can do something here
}
}, 100);
healcode.js should replace everything inside <healcode-widget></healcode-widget> during init. So, if your <div>-element is no longer inside, the widget has loaded and initialized.
Hope that helps.
If you just want to load some markup and content and then run some script afterwards, you can use jQuery. You should use something like the following in script#1 to run a function in script#2
$.get( "ajax/test.html", function( data ) {
// Now you can do something with your data and run other script.
console.log("It's Loaded");
});
The function is called, after ajax/test.html is loaded.
Hope that helps
I have a question about javascript/html.
First, I have this:
var post = document.body.getElementsByClassName("post");
var x=post[i].getElementsByClassName("MyDiv")[0].innerHTML;
I get from the debugger that x is not defined, it doesn't exists.
This javascript function runs onload of the body. I am sure that I gave the right classnames in my javascript, so it should find my div.
So, I read somewhere that sometimes javascript does not find an element because it is not yet there, it is not yet created in the browser ( whatever that means).
Is it possible that my function can't find the div with that classname because of this reason?
Is there a solution?
So, I read somewhere that sometimes javascript does not find an element because it is not yet there, it is not yet created in the browser ( whatever that means).
Browsers create the DOM progressively as they get the markup. When a script element is encountered, all processing of the markup stops (except where defer and async have an effect) while the script is run. If the script attempts to access an element that hasn't been created yet (probably because its markup hasn't been processed yet) then it won't be found.
This javascript function runs onload of the body.
If that means you are using something like:
<body onload="someFn()"...>
or perhaps
<script>
window.onload = function() {
someFn();
...
}
</script>
then when the function is called, all DOM nodes are available. Some, like images, may not be fully loaded, but their elements have been created.
If it means you have the script in the body and aren't using the load event, you should move the script to the bottom of the page (e.g. just before the closing body tag) and see if that fixes the issue.
Okay, instead of calling functions with
body onload, use jQuery's ready() function, or, if you don't want to use jQuery, you can use pure javascript, but this is up to you:
// jQuery
$(document).ready(function() {
var post = document.getElementsByClassName("post"),
x = post[i].getElementsByClassName("MyDiv")[0].innerHTML;
});
// JavaScript
window.onload = function initialization() {
var post = document.getElementsByClassName("post"),
x = post[i].getElementsByClassName("MyDiv")[0].innerHTML;
}
A few side notes, I don't know what the use of innerHTML
is, and also if you're doing a for loop with i then definitely
post that code, that's kind of important.
After some discussion, my answer seems to have worked for you, but you can also place your script at the end of your body tag as #RobG has suggested.
I am trying to load Skyscanner API dynamically but it doesn't seem to work. I tried every possible way I could think of and all it happens the content disappears.
I tried console.log which gives no results; I tried elements from chrome's developers tools and while all the content's css remains the same, still the content disappears (I thought it could be adding display:none on the html/body sort of). I tried all Google's asynch tricks, yet again blank page. I tried all js plugins for async loading with still the same results.
Skyscanner's API documentation is poor and while they offer a callback it doesn't work the way google's API's callback do.
Example: http://jsfiddle.net/7TWYC/
Example with loading API in head section: http://jsfiddle.net/s2HkR/
So how can I load the api on button click or async? Without the file being in the HEAD section. If there is a way to prevent the document.write to make the page blank or any other way. I wouldn't mind using plain js, jQuery or PHP.
EDIT:
I've set a bounty to 250 ontop of the 50 I had previously.
Orlando Leite answered a really close idea on how to make this asynch api load although some features doesn't work such as selecting dates and I am not able to set styling.
I am looking for an answer of which I will be able to use all the features so that it works as it would work if it was loading on load.
Here is the updated fiddle by Orlando: http://jsfiddle.net/cxysA/12/
-
EDIT 2 ON Gijs ANSWER:
Gijs mentioned two links onto overwriting document.write. That sounds an awesome idea but I think it is not possible to accomplish what I am trying.
I used John's Resig way to prevent document.write of which can be found here: http://ejohn.org/blog/xhtml-documentwrite-and-adsense/
When I used this method, I load the API successfuly but the snippets.js file is not loading at all.
Fiddle: http://jsfiddle.net/9HX7N/
I belive what you want is it:
function loadSkyscanner()
{
function loaded()
{
t.skyscanner.load('snippets', '1', {'nocss' : true});
var snippet = new t.skyscanner.snippets.SearchPanelControl();
snippet.setCurrency('GBP');
snippet.setDeparture('uk');
snippet.draw(document.getElementById('snippet_searchpanel'));
}
var t = document.getElementById('sky_loader').contentWindow;
var head = t.document.getElementsByTagName('head')[0];
var script = document.createElement('script');
script.type = 'text/javascript';
script.onreadystatechange= function() {
if(this.readyState == 'complete') loaded();
}
script.onload= loaded;
script.src= 'http://api.skyscanner.net/api.ashx?key=PUT_HERE_YOUR_SKYSCANNER_API_KEY';
head.appendChild(script);
}
$("button").click(function(e)
{
loadSkyscanner();
});
It's load skyscanner in iframe#sky_loader, after call loaded function to create the SearchPanelControl. But in the end, snippet draws in the main document. It's really a bizarre workaround, but it works.
The only restriction is, you need a iframe. But you can hide it using display:none.
A working example
EDIT
Sorry guy, I didn't see it. Now we can see how awful is skyscanner API. It puts two divs to make the autocomplete, but not relative to the element you call to draw, but the document.
When a script is loaded in a iframe, document is the iframe document.
There is a solution, but I don't recommend, is really a workaround:
function loadSkyscanner()
{
var t;
this.skyscanner;
var iframe = $("<iframe id=\"sky_loader\" src=\"http://fiddle.jshell.net/orlleite/2TqDu/6/show/\"></iframe>");
function realWorkaround()
{
var tbody = t.document.getElementsByTagName("body")[0];
var body = document.getElementsByTagName("body")[0];
while( tbody.children.length != 0 )
{
var temp = tbody.children[0];
tbody.removeChild( temp );
body.appendChild( temp );
}
}
function snippetLoaded()
{
skyscanner = t.skyscanner;
var snippet = new skyscanner.snippets.SearchPanelControl();
snippet.setCurrency('GBP');
snippet.setDeparture('uk');
snippet.draw(document.getElementById('snippet_searchpanel'));
setTimeout( realWorkaround, 2000 );
}
var loaded = function()
{
console.log( "loaded" );
t = document.getElementById('sky_loader').contentWindow;
t.onLoadSnippets( snippetLoaded );
}
$("body").append(iframe);
iframe.load(loaded);
}
$("button").click(function(e)
{
loadSkyscanner();
});
Load a iframe with another html who loads and callback when the snippet is loaded. After loaded create the snippet where you want and after set a timeout because we can't know when the SearchPanelControl is loaded. This realWorkaround move the autocomplete divs to the main document.
You can see a work example here
The iframe loaded is this
EDIT
Fixed the bug you found and updated the link.
the for loop has gone and added a while, works better now.
while( tbody.children.length != 0 )
{
var temp = tbody.children[0];
tbody.removeChild( temp );
body.appendChild( temp );
}
For problematic cases like this, you can just overwrite document.write. Hacky as hell, but it works and you get to decide where all the content goes. See eg. this blogpost by John Resig. This ignores IE, but with a bit of work the trick works in IE as well, see eg. this blogpost.
So, I'd suggest overwriting document.write with your own function, batch up the output where necessary, and put it where you like (eg. in a div at the bottom of your <body>'). That should prevent the script from nuking your page's content.
Edit: OK, so I had/took some time to look into this script. For future reference, use something like http://jsbeautifier.org/ to investigate third-party scripts. Much easier to read that way. Fortunately, there is barely any obfuscation/minification at all, and so you have a supplement for their API documentation (which I was unable to find, by the way -- I only found 'code wizards', which I had no interest in).
Here's an almost-working example: http://jsfiddle.net/a8q2s/1/
Here's the steps I took:
override document.write. This needs to happen before you load the initial script. Your replacement function should append their string of code into the DOM. Don't call the old document.write, that'll just get you errors and won't do what you want anyway. In this case you're lucky because all the content is in a single document.write call (check the source of the initial script). If this weren't the case, you'd have to batch everything up until the HTML they'd given you was valid and/or you were sure there was nothing else coming.
load the initial script on the button click with jQuery's $.getScript or equivalent. Pass a callback function (I used a named function reference for clarity, but you can inline it if you prefer).
Tell Skyscanner to load the module.
Edit #2: Hah, they have an API (skyscanner.loadAndWait) for getting a callback once their script has loaded. Using that works:
http://jsfiddle.net/a8q2s/3/
(note: this still seems to use a timeout loop internally)
In the skyrunner.js file they are using document.write to make the page blank on load call back... So here are some consequences in your scenario..
This is making page blank when you click on button.
So, it removes everything from page even 'jQuery.js' that is why call back is not working.. i.e main function is cannot be invoked as this is written using jQuery.
And you have missed a target 'div' tag with id = map(according to the code). Actually this is the target where map loads.
Another thing i have observed is maps is not actually a div in current context, that is maps api to load.
Here you must go with the Old school approach, That is.. You should include your skyrunner.js file at the top of the head content.
So try downloading that file and include in head tag.
Thanks
I wrote a Greasemonkey script and it affect the firstly loaded posts on Facebook.
but after you scroll down on the feed, the script doesn't work on the newly loaded posts.
Is there a way to re-run the script for those posts, or something like that? can anyone help me?
Update:
This question and answer are very old and DOMSubtreeModified is deprecated.
I no longer recommend this approach. Instead see:
Fire Greasemonkey script on AJAX request
Run Greasemonkey script on the same page, multiple times?
Choosing and activating the right controls on an AJAX-driven site
Or use MutationObserver via a library like Mutation Summary, or similar.
Old answer:
Yes, since you are using Firefox, you can trigger off the DOMSubtreeModified event.
To do this, first wrap the code part of your current script in a function; for example:
// ==UserScript==
// #name Facebook Fixer
// ==/UserScript==
function LocalMain ()
{
//--- Do all of your actions here.
}
LocalMain (); //-- Fire GM script once, normally.
Next, find the node that contains the newly loaded posts. Say that you find that it is a div with the id "All_posts_go_here" (I don't use Facebook, be sure to find the correct node, and do not use body, the browser will slow to a crawl).
Once you've identified the correct node, you can set the event listener. But, you also need a short time delay because the node changes come hundreds at a time and you need to wait until the current batch is done.
So, putting it all together, the code looks like this:
if (window.top != window.self) //don't run on frames or iframes
return;
function LocalMain ()
{
//--- Do all of your actions here.
}
LocalMain (); //-- Fire GM script once, normally.
var PostsChangedByAJAX_Timer = '';
//--- Change this next line to find the correct element; sample shown.
var PostContainerNode = document.getElementById ('All_posts_go_here');
PostContainerNode.addEventListener ("DOMSubtreeModified", PageBitHasLoaded, false);
function PageBitHasLoaded (zEvent)
{
/*--- Set and reset a timer so that we run our code (LocalMain() ) only
AFTER the last post -- in a batch -- is added. Adjust the time if needed, but
half a second is a good all-round value.
*/
if (typeof PostsChangedByAJAX_Timer == "number")
{
clearTimeout (PostsChangedByAJAX_Timer);
PostsChangedByAJAX_Timer = '';
}
PostsChangedByAJAX_Timer = setTimeout (function() {LocalMain (); }, 555);
}
Beware that I'm assuming the node is not an iframe. If it is, then a different approach may be required.