First opportunity for document.body.appendChild - javascript

I am looking for the first opportunity to call document.body.appendChild to attach an element. I am currently using onload of body but as I understand it this waits until images and subframes load before triggering.
I require only that the solution work in IE (this is for an IE specific demo), but believe in the importance of giving cross-browser answers for other people to reference, so points if you give both.
Below is an illustration of what I am already doing.
<html>
<head>
<title>Insertion</title>
<script type="text/javascript">
function insertStuff() {
var iframe = document.createElement("iframe");
document.body.appendChild(iframe);
}
</script>
</head>
<body onload="insertStuff()">
</body>
</html>

<html>
<head>
<title>Insertion</title>
</head>
<body>
<script type="text/javascript">
function insertStuff() {
var iframe = document.createElement("iframe");
document.body.appendChild(iframe);
}
insertStuff()
</script>
<!-- Here goes all the other elements -->
</body>
</html>
This would be cross browser and work for IE6 and above for sure. Not sure about anything below that

Related

alert is executing before html loads

Hello my questions is about how a webpage is loaded! Here is my code:
<!DOCTYPE html>
<html>
<head>
<title>JavaScript</title>
</head>
<body>
<h1>Waiting</h1>
<script type="text/javascript">
alert("Why?");
</script>
</body>
</html>
I cannot for the life of me figure out why the alert is running before the heading is displayed. It is my understanding that since the alert is right above the closing body tag it will be the last thing run. Why is the page waiting for me to close out the alert before displaying the heading?
Thanks for the help!
Edit: I ran this code in firefox rather than chrome and it worked how I wanted it to - the heading displayed first before the alert ran.
You need to execute your script after the page loads with
<body onload="script();">
An external script will execute before the page loads.
<body onload="script();">
<h1>Waiting</h1>
<script type="text/javascript">
function script() {alert("Why?");}
</script>
</body>
You can use setTimeout() to show the alert after a few seconds (when the page should have loaded).
<!DOCTYPE html>
<html>
<head>
<title>JavaScript</title>
</head>
<body>
<h1>Waiting</h1>
<script type="text/javascript">
setTimeout(function(){
alert("Why?");
}, 1000);//wait 1000 milliseconds
</script>
</body>
</html>
You can check if the header (the h1 tag) is there and only alert if it is there.
<!DOCTYPE html>
<html>
<head>
<title>JavaScript</title>
</head>
<body>
<h1 id="header">Waiting</h1>
<script type="text/javascript">
var x;
x = setInterval(function(){
if(document.getElementById("header")){
alert("Why?");
clearInterval(x);
}
}, 100);
</script>
</body>
</html>
The simplest workaround code without using JQuery I could write is this. Please check it.
<!DOCTYPE html>
<html>
<head>
<title>JavaScript</title>
</head>
<body>
<h1>Waiting</h1>
<script type="text/javascript">
window.onload = function(){
setTimeout(()=>{
alert("Why?");
},10)
}
</script>
</body>
</html>
The cleanest way to do this seems like it would be to put your javascript in a separate file, and load it with the defer attribute. This will cause it to fire after the DOM loads (technically, just before DOMContentLoaded, but it doesn't work consistently across browsers unless there is a src attribute, which is why you would need to move it to an external file.
<script src="myScript.js" defer></script>
Oddly, adding some CSS to your heading could also affect this since JS is supposed to execute in order after any pending CSS.
The timeout function or a $(document).ready() function will do what you need in theory, but a timeout could need to be adjusted based on the complexity of the page, and if you aren't already using jQuery, you probably won't want to add it just to use $(document).ready().

Get Back Button to work on parent page when iframe is involved

I am working on a legacy app that has an iframe involved. The back button is working on the iframe and I need it to bypass the iframe and work on the parent window only.
Here is a dumbed down version of the issue and description of what I know.
the main page "index.html" has an iframe that is being added via javascript. It loads a.html, makes an ajax call that then does a window.location = "b.html" At this point if you use the back button it essentiallys makes the iframe go back to a.html and then redirects to b.html so you are effectively stuck on the page. If I remove the ajax call and do an window.location on load everything works ok. However given the architecture and what happen on the page I can't remove the Ajax call from the picture.
Here is the code I am looking at, let me know your thoughts on how to solve this issue. Also I should mention in Chrome 41 this isn't an issue, however the newer chrome 48 and 49 it is an issue. I tried history.replaceState but wasn't able to figure out a way to use it in this situation that made things work.
index.html
<html>
<head>
<title></title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.min.js"></script>
</head>
<body>
hello world!
<div id="iframeContainer"></div>
<script>
$(function () {
var newIframe = document.createElement('iframe');
newIframe.src = "a.html";
newIframe.id = "A";
document.getElementById("iframeContainer").appendChild(newIframe);
});
</script>
</body>
</html>
a.html
<html>
<head>
<title></title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.min.js"></script>
</head>
<body style="background-color:#F00;">
<script>
$(function(){
$.ajax({
url:"b.html",
complete:function(){
window.location="b.html";
}
});
});
</script>
</body>
</html>
b.html
<html>
<head>
<title></title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.min.js"></script>
</head>
<body style="background-color:#00F;">
<script>
$(function(){
})
</script>
</body>
</html>
This is only possible in HTML5 compatible browsers, and it would go something like this..
This goes in the child frame..
// catch the back button click.
window.onpopstate = function(event) {
// make the parent window go back
top.history.back();
};
This also only works if both frames are in teh same domain.

JavaScript code in iframe

I need to run JavaScript code in iframe. But script with id "us" loaded after creating iframe. How to run this javascript in iframe?
<iframe id="preview">
#document
<html>
<head>
<script src="http://code.jquery.com/jquery-latest.min.js"></script>
<script id="us" type="text/javascript">
$("#preview").ready(function() {
$(".test").click(function() {
alert(true);
});
});
</script>
</head>
<body>
<style></style>
<div class="test"></div>
</body>
</html>
</iframe>
Thanks in advance.
The IFrame has no access to what's outside of it. Everything inside IFrame is separate page ergo you threat it like so. So you do your document.ready in it.
Example: http://jsfiddle.net/ZTJUB/
// Since this is page you wait until it's loaded
$(function() {
$(".test").click(function() {
alert(true);
});
});
The jQuery instance inside of the iFrame doesn't know it's supposed to be traversing the parent DOM, so therefore it won't know where to look for an element with the id "preview"
As per my comments above, you should attach to the iframe's document.ready, like this:
// Since this is page you wait until it's loaded
$(document).ready(function() {
$(".test").click(function() {
alert(true);
});
});
EDIT:
Just realizing you are probably having an entirely different issue here - Html code as IFRAME source rather than a URL - if you are trying to embed the iframe code inline, you are going to have problems. Take the following code for example:
<html>
<head></head>
<body>
Some stuff here
<iframe id="preview">
<html>
<head>
<script src="http://code.jquery.com/jquery-latest.min.js"></script>
<script id="us" type="text/javascript">
$(document).ready(function() {
$(".test").click(function() {
alert(true);
});
});
</script>
</head>
<body>
<style></style>
<div class="test">test</div>
</body>
</html>
</iframe>
</body>
</html>
if you render that page in firefox, and then inspect the source in firebug, you'll see:
<html>
<head></head>
<body>
Some stuff here
<iframe id="preview">
<html>
<head></head>
<body></body>
</html>
</iframe>
</body>
</html>
This is happening because the browser isn't expecting to see the code inline between the iframe tags.
Since you're not addressing the questions in the comments to better clarify what you are trying to do... I shall assume you are trying to access content IN your iframe FROM your parent page. Since the other answer should work fine if trying to run it from within the iframe.
On the parent page try something like:
$(function() {
$("#preview").load(function ()
$("#preview").contents().find(".test").click(function() {alert(true);});
});
});
*This assumes both parent and iframe are on the same domain.

Nested iframes, AKA Iframe Inception

Using jQuery I am trying to access div id="element".
<body>
<iframe id="uploads">
<iframe>
<div id="element">...</div>
</iframe>
</iframe>
</body>
All iframes are on the same domain with no www / non-www issues.
I have successfully selected elements within the first iframe but not the second nested iframe.
I have tried a few things, this is the most recent (and a pretty desperate attempt).
var iframe = jQuery('#upload').contents();
var iframeInner = jQuery(iframe).find('iframe').contents();
var iframeContent = jQuery(iframeInner).contents().find('#element');
// iframeContent is null
Edit:
To rule out a timing issue I used a click event and waited a while.
jQuery().click(function(){
var iframe = jQuery('#upload').contents().find('iframe');
console.log(iframe.find('#element')); // [] null
});
Any ideas?
Thanks.
Update:
I can select the second iframe like so...
var iframe = jQuery('#upload').contents().find('iframe');
The problem now seems to be that the src is empty as the iframe is generated with javascript.
So the iframe is selected but the content length is 0.
Thing is, the code you provided won't work because the <iframe> element has to have a "src" property, like:
<iframe id="uploads" src="http://domain/page.html"></iframe>
It's ok to use .contents() to get the content:
$('#uploads).contents() will give you access to the second iframe, but if that iframe is "INSIDE" the http://domain/page.html document the #uploads iframe loaded.
To test I'm right about this, I created 3 html files named main.html, iframe.html and noframe.html and then selected the div#element just fine with:
$('#uploads').contents().find('iframe').contents().find('#element');
There WILL be a delay in which the element will not be available since you need to wait for the iframe to load the resource. Also, all iframes have to be on the same domain.
Hope this helps ...
Here goes the html for the 3 files I used (replace the "src" attributes with your domain and url):
main.html
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>main.html example</title>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script>
$(function () {
console.log( $('#uploads').contents().find('iframe').contents().find('#element') ); // nothing at first
setTimeout( function () {
console.log( $('#uploads').contents().find('iframe').contents().find('#element') ); // wait and you'll have it
}, 2000 );
});
</script>
</head>
<body>
<iframe id="uploads" src="http://192.168.1.70/test/iframe.html"></iframe>
</body>
iframe.html
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>iframe.html example</title>
</head>
<body>
<iframe src="http://192.168.1.70/test/noframe.html"></iframe>
</body>
noframe.html
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>noframe.html example</title>
</head>
<body>
<div id="element">some content</div>
</body>
var iframeInner = jQuery(iframe).find('iframe').contents();
var iframeContent = jQuery(iframeInner).contents().find('#element');
iframeInner contains elements from
<div id="element">other markup goes here</div>
and iframeContent will find for elements which are inside of
<div id="element">other markup goes here</div>
(find doesn't search on current element) that's why it is returning null.
Hey I got something that seems to be doing what you want a do. It involves some dirty copying but works. You can find the working code here
So here is the main html file :
<!DOCTYPE html>
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
Iframe = $('#frame1');
Iframe.on('load', function(){
IframeInner = Iframe.contents().find('iframe');
IframeInnerClone = IframeInner.clone();
IframeInnerClone.insertAfter($('#insertIframeAfter')).css({display:'none'});
IframeInnerClone.on('load', function(){
IframeContents = IframeInner.contents();
YourNestedEl = IframeContents.find('div');
$('<div>Yeepi! I can even insert stuff!</div>').insertAfter(YourNestedEl)
});
});
});
</script>
</head>
<body>
<div id="insertIframeAfter">Hello!!!!</div>
<iframe id="frame1" src="Test_Iframe.html">
</iframe>
</body>
</html>
As you can see, once the first Iframe is loaded, I get the second one and clone it. I then reinsert it in the dom, so I can get access to the onload event. Once this one is loaded, I retrieve the content from non-cloned one (must have loaded as well, since they use the same src). You can then do wathever you want with the content.
Here is the Test_Iframe.html file :
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<div>Test_Iframe</div>
<iframe src="Test_Iframe2.html">
</iframe>
</body>
</html>
and the Test_Iframe2.html file :
<!DOCTYPE html>
<html>
<head>
</head>
<body>
<div>I am the second nested iframe</div>
</body>
</html>
You probably have a timing issue. Your document.ready commend is probably firing before the the second iFrame is loaded. You dont have enough info to help much further- but let us know if that seems like the possible issue.
You should use live method for elements which are rendered later, like colorbox, hidden fields or iframe
$(".inverter-value").live("change",function() {
elem = this
$.ajax({
url: '/main/invertor_attribute/',
type: 'POST',
aysnc: false,
data: {id: $(this).val() },
success: function(data){
// code
},
dataType: 'html'
});
});
I think the best way to reach your div:
var your_element=$('iframe#uploads').children('iframe').children('div#element');
It should work well.
If browser supports iframe, then DOM inside iframe come from src attribute of respective tag. Contents that are inside iframe tag are used as a fall back mechanism where browser does not supports iframe tag.
Ref: http://www.w3schools.com/tags/tag_iframe.asp
I guess your problem is that jQuery is not loaded in your iframes.
The safest approach is to rely on pure DOM-based methods to parse your content.
Or else, start with jQuery, and then once inside your iframes, test once if typeof window.jQuery == 'undefined', if it's true, jQuery is not enabled inside it and fallback on DOM-based method.

How to get notified about IFRAME appended dynamically and loaded?

I need to add an ability to a Firefox extension to handle cases when IFRAME elements are being added dynamically. Is there a way to get notified when IFRAME document is loaded in such a case?
For example:
<html>
<head>
<title>iframe test</title>
<script type="text/javascript">
function addIFrame() {
var ifrm = document.createElement("iframe");
ifrm.setAttribute("src", " http://www.google.com/");
document.body.appendChild(ifrm);
}
setTimeout('addIFrame()', 3000);
</script>
</head>
<body>
<p>A new <iframe> will be added in 3 seconds:</p>
</body>
</html>
You can set a capturing load listener on the tabbrowser and then check that the event's target is an <html:iframe>.

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