jQuery .ready in a dynamically inserted iframe - javascript

We are using jQuery thickbox to dynamically display an iframe when someone clicks on a picture. In this iframe, we are using galleria a javascript library to display multiple pictures.
The problem seems to be that $(document).ready in the iframe seems to be fired too soon and the iframe content isn't even loaded yet, so galleria code is not applied properly on the DOM elements. $(document).ready seems to use the iframe parent ready state to decide if the iframe is ready.
If we extract the function called by document ready in a separate function and call it after a timeout of 100 ms. It works, but we can't take the chance in production with a slow computer.
$(document).ready(function() { setTimeout(ApplyGalleria, 100); });
My question: which jQuery event should we bind to to be able to execute our code when the dynamic iframe is ready and not just it's a parent?

I answered a similar question (see Javascript callback when IFRAME is finished loading?).
You can obtain control over the iframe load event with the following code:
function callIframe(url, callback) {
$(document.body).append('<IFRAME id="myId" ...>');
$('iframe#myId').attr('src', url);
$('iframe#myId').load(function() {
callback(this);
});
}
In dealing with iframes I found good enough to use load event instead of document ready event.

Using jQuery 1.3.2 the following worked for me:
$('iframe').ready(function() {
$('body', $('iframe').contents()).html('Hello World!');
});
REVISION:!
Actually the above code sometimes looks like it works in Firefox, never looks like it works in Opera.
Instead I implemented a polling solution for my purposes. Simplified down it looks like this:
$(function() {
function manipIframe() {
el = $('body', $('iframe').contents());
if (el.length != 1) {
setTimeout(manipIframe, 100);
return;
}
el.html('Hello World!');
}
manipIframe();
});
This doesn't require code in the called iframe pages. All code resides and executes from the parent frame/window.

In IFrames I usually solve this problem by putting a small script to the very end of the block:
<body>
The content of your IFrame
<script type="text/javascript">
//<![CDATA[
fireOnReadyEvent();
parent.IFrameLoaded();
//]]>
</script>
</body>
This work most of the time for me. Sometimes the simplest and most naive solution is the most appropriate.

Following DrJokepu's and David Murdoch idea I implemented a more complete version.
It requires jQuery on both the parent and iframe and the iframe to be in your control.
iframe code:
var iframe = window.frameElement;
if (iframe){
iframe.contentDocument = document;//normalization: some browsers don't set the contentDocument, only the contentWindow
var parent = window.parent;
$(parent.document).ready(function(){//wait for parent to make sure it has jQuery ready
var parent$ = parent.jQuery;
parent$(iframe).trigger("iframeloading");
$(function(){
parent$(iframe).trigger("iframeready");
});
$(window).load(function(){//kind of unnecessary, but here for completion
parent$(iframe).trigger("iframeloaded");
});
$(window).unload(function(e){//not possible to prevent default
parent$(iframe).trigger("iframeunloaded");
});
$(window).on("beforeunload",function(){
parent$(iframe).trigger("iframebeforeunload");
});
});
}
parent test code:
$(function(){
$("iframe").on("iframeloading iframeready iframeloaded iframebeforeunload iframeunloaded", function(e){
console.log(e.type);
});
});

Found the solution to the problem.
When you click on a thickbox link that open a iframe, it insert an iframe with an id of TB_iframeContent.
Instead of relying on the $(document).ready event in the iframe code, I just have to bind to the load event of the iframe in the parent document:
$('#TB_iframeContent', top.document).load(ApplyGalleria);
This code is in the iframe but binds to an event of a control in the parent document. It works in FireFox and IE.

This function from this answer is the best way to handle this as $.ready explicitly fails for iframes. Here's the decision not to support this.
The load event also doesn't fire if the iframe has already loaded. Very frustrating that this remains a problem in 2020!
function onIframeReady($i, successFn, errorFn) {
try {
const iCon = $i.first()[0].contentWindow,
bl = "about:blank",
compl = "complete";
const callCallback = () => {
try {
const $con = $i.contents();
if($con.length === 0) { // https://git.io/vV8yU
throw new Error("iframe inaccessible");
}
successFn($con);
} catch(e) { // accessing contents failed
errorFn();
}
};
const observeOnload = () => {
$i.on("load.jqueryMark", () => {
try {
const src = $i.attr("src").trim(),
href = iCon.location.href;
if(href !== bl || src === bl || src === "") {
$i.off("load.jqueryMark");
callCallback();
}
} catch(e) {
errorFn();
}
});
};
if(iCon.document.readyState === compl) {
const src = $i.attr("src").trim(),
href = iCon.location.href;
if(href === bl && src !== bl && src !== "") {
observeOnload();
} else {
callCallback();
}
} else {
observeOnload();
}
} catch(e) {
errorFn();
}
}

Basically what others have already posted but IMHO a bit cleaner:
$('<iframe/>', {
src: 'https://example.com/',
load: function() {
alert("loaded")
}
}).appendTo('body');

Try this,
<iframe id="testframe" src="about:blank" onload="if (testframe.location.href != 'about:blank') testframe_loaded()"></iframe>
All you need to do then is create the JavaScript function testframe_loaded().

I'm loading the PDF with jQuery ajax into browser cache. Then I create embedded element with data already in browser cache. I guess it will work with iframe too.
var url = "http://example.com/my.pdf";
// show spinner
$.mobile.showPageLoadingMsg('b', note, false);
$.ajax({
url: url,
cache: true,
mimeType: 'application/pdf',
success: function () {
// display cached data
$(scroller).append('<embed type="application/pdf" src="' + url + '" />');
// hide spinner
$.mobile.hidePageLoadingMsg();
}
});
You have to set your http headers correctly as well.
HttpContext.Response.Expires = 1;
HttpContext.Response.Cache.SetNoServerCaching();
HttpContext.Response.Cache.SetAllowResponseInBrowserHistory(false);
HttpContext.Response.CacheControl = "Private";

This was the exact issue I ran into with our client. I created a little jquery plugin that seems to work for iframe readiness. It uses polling to check the iframe document readyState combined with the inner document url combined with the iframe source to make sure the iframe is in fact "ready".
The issue with "onload" is that you need access to the actual iframe being added to the DOM, if you don't then you need to try to catch the iframe loading which if it is cached then you may not. What I needed was a script that could be called anytime, and determine whether or not the iframe was "ready" or not.
Here's the question:
Holy grail for determining whether or not local iframe has loaded
and here's the jsfiddle I eventually came up with.
https://jsfiddle.net/q0smjkh5/10/
In the jsfiddle above, I am waiting for onload to append an iframe to the dom, then checking iframe's inner document's ready state - which should be cross domain because it's pointed to wikipedia - but Chrome seems to report "complete". The plug-in's iready method then gets called when the iframe is in fact ready. The callback tries to check the inner document's ready state again - this time reporting a cross domain request (which is correct) - anyway it seems to work for what I need and hope it helps others.
<script>
(function($, document, undefined) {
$.fn["iready"] = function(callback) {
var ifr = this.filter("iframe"),
arg = arguments,
src = this,
clc = null, // collection
lng = 50, // length of time to wait between intervals
ivl = -1, // interval id
chk = function(ifr) {
try {
var cnt = ifr.contents(),
doc = cnt[0],
src = ifr.attr("src"),
url = doc.URL;
switch (doc.readyState) {
case "complete":
if (!src || src === "about:blank") {
// we don't care about empty iframes
ifr.data("ready", "true");
} else if (!url || url === "about:blank") {
// empty document still needs loaded
ifr.data("ready", undefined);
} else {
// not an empty iframe and not an empty src
// should be loaded
ifr.data("ready", true);
}
break;
case "interactive":
ifr.data("ready", "true");
break;
case "loading":
default:
// still loading
break;
}
} catch (ignore) {
// as far as we're concerned the iframe is ready
// since we won't be able to access it cross domain
ifr.data("ready", "true");
}
return ifr.data("ready") === "true";
};
if (ifr.length) {
ifr.each(function() {
if (!$(this).data("ready")) {
// add to collection
clc = (clc) ? clc.add($(this)) : $(this);
}
});
if (clc) {
ivl = setInterval(function() {
var rd = true;
clc.each(function() {
if (!$(this).data("ready")) {
if (!chk($(this))) {
rd = false;
}
}
});
if (rd) {
clearInterval(ivl);
clc = null;
callback.apply(src, arg);
}
}, lng);
} else {
clc = null;
callback.apply(src, arg);
}
} else {
clc = null;
callback.apply(this, arguments);
}
return this;
};
}(jQuery, document));
</script>

Related

Waiting for multiple iFrames to load before executing function

Forgive my naivety, this probably is quite obvious, I just can't see it now.
Please tell me what is wrong with the following code:
$('#iframe1').load(function(){
$('#iframe2').load(function(){
alert('loaded!');
});
});
The idea is to wait until both iframes have fully loaded, then alert "loaded" - of course this is a simplified example for the sake of stack.
The script sits in script tags at the end of the body of the html doc.
#Quertiy answer is perfectly fine, but not very jQuery-ish. It is hard-coded for 2 iframes only.
The beauty of jQuery is that you can make it work for the most number of people, with as little friction as possible.
I've advised a very simplistic plugin that does nearly what is present on that answer, but in a more open way. It not only works on iframes, but also on images, audio, video and whatever has a onload event!
Without further due, here's the code:
(function($){
$.fn.extend({allLoaded: function(fn){
if(!(fn instanceof Function))
{
throw new TypeError('fn must be a function');
}
var $elems = this;
var waiting = this.length;
var handler = function(){
--waiting;
if(!waiting)
{
setTimeout(fn.bind(window), 4);
}
};
return $elems.one('load.allLoaded', handler);
}});
})(window.jQuery);
It works by adding a load handler to every element in that selection. Since it is a plugin, you can use in whatever way you decide to use it.
Here's an example, that loads 30 random images:
//plugin code
(function($){
$.fn.extend({allLoaded: function(fn){
if(!(fn instanceof Function))
{
throw new TypeError('fn must be a function');
}
var $elems = this;
var waiting = this.length;
var handler = function(){
--waiting;
if(!waiting)
{
setTimeout(fn.bind(window), 4);
}
};
return $elems.one('load.allLoaded', handler);
}});
})(window.jQuery);
$(function(){
//generates the code for the 30 images
for(var i = 0, html = ''; i < 30; i++)
html += '<img data-src="http://lorempixel.com/g/400/200/?_=' + Math.random() + '">';
//stuffs the code into the body
$('#imgs').html(html);
//we select all images now
$('img')
.allLoaded(function(){
//runs when done
alert('loaded all')
})
.each(function(){
//the image URL is on a `data` attribute, to delay the loading
this.src = this.getAttribute('data-src')
})
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.0/jquery.min.js"></script>
<div id="imgs"></div>
Your problem, as said before many times, is that you have a load event attached to your iframe. That event is fired everytime the content change.
After that, you set a new event on #iframe2. When it's content changes, it will fire events left and right, above and beyound what you wish!
The best aproach is to keep track of which ones you loaded or not. After all have been loaded, you simply run the function.
The problem is that you're waiting until #iframe1 loads before you attach a handler for #iframe2 loading. So if #iframe2 loads first, you'll never get your callback.
Instead, watch the load event on both of them and track which ones you've seen:
var seen1 = false,
seen2 = false;
$('#iframe1, #iframe2').load(function(){
if (this.id == "iframe1") {
seen1 = true;
} else {
seen2 = true;
}
if (seen1 && seen2) {
alert('loaded!');
}
});
Why do you expect 2nd iframe to load after the first one?
~function () {
var loaded = 0;
$('#iframe1, #iframe2').load(function (){
if (++loaded === 2) {
alert('loaded!');
}
});
}()

Alternatives to SetTimeout

Hi I have written some javascript code to generate an iFrame and insert content inside. But I don't want to use setTimeout and I want to refactor the code. I tried to use document.ready() and window.onLoad() and they don't work.
This is my code:
onShow: function() {
//TODO: why 200 ms wait? why not wait for specific event
setTimeout(this.injectHtml.bind(this), 200);
},
injectHtml: function() {
var iframe = this.el;
if (iframe.contentWindow === null) { //Check for contentWindow for null.
$(iframe).html(this.params.html);
} else { //If contentWindow is present then open the document for writing.
iframe = iframe.contentWindow;
iframe.document.open('text/html');
iframe.document.write(this.params.html);
iframe.document.close();
$(this.el).on('load', function() {
var iframe = $(this).contents();
iframe.find("#langSelect").off("change");
iframe.find("#langSelect").on("change", function() { //If another language is selected from Dropdown.
abc.languages.setSelected($(this).val());
abc.elements.setLanguage();
Vent.trigger(Vent.Event.LANGUAGE_SELECTED, $(this).val());
});
});
}
}
I'm really confused here. Can anyone shed light?
I have tried this as well:
Case#1:
var _this=this;
$(document).ready(function(){
_this.injectHtml.bind(_this); //Does not work. Everything loads, I get empty page
});
Case#2:
window.onLoad = function(){
this.injectHtml.bind(this);
};
can anyone help?

'load' event not firing when iframe is loaded in Chrome

I am trying to display a 'mask' on my client while a file is dynamically generated server side. Seems like the recommend work around for this (since its not ajax) is to use an iframe and listen from the onload or done event to determine when the file has actually shipped to the client from the server.
here is my angular code:
var url = // url to my api
var e = angular.element("<iframe style='display:none' src=" + url + "></iframe>");
e.load(function() {
$scope.$apply(function() {
$scope.exporting = false; // this will remove the mask/spinner
});
});
angular.element('body').append(e);
This works great in Firefox but no luck in Chrome. I have also tried to use the onload function:
e.onload = function() { //unmask here }
But I did not have any luck there either.
Ideas?
Unfortunately it is not possible to use an iframe's onload event in Chrome if the content is an attachment. This answer may provide you with an idea of how you can work around it.
I hate this, but I couldn't find any other way than checking whether it is still loading or not except by checking at intervals.
var timer = setInterval(function () {
iframe = document.getElementById('iframedownload');
var iframeDoc = iframe.contentDocument || iframe.contentWindow.document;
// Check if loading is complete
if (iframeDoc.readyState == 'complete' || iframeDoc.readyState == 'interactive') {
loadingOff();
clearInterval(timer);
return;
}
}, 4000);
You can do it in another way:
In the main document:
function iframeLoaded() {
$scope.$apply(function() {
$scope.exporting = false; // this will remove the mask/spinner
});
}
var url = // url to my api
var e = angular.element("<iframe style='display:none' src=" + url + "></iframe>");
angular.element('body').append(e);
In the iframe document (this is, inside the html of the page referenced by url)
window.onload = function() {
parent.iframeLoaded();
}
This will work if the main page, and the page inside the iframe are in the same domain.
Actually, you can access the parent through:
window.parent
parent
//and, if the parent is the top-level document, and not inside another frame
top
window.top
It's safer to use window.parent since the variables parent and top could be overwritten (usually not intended).
you have to consider 2 points:
1- first of all, if your url has different domain name, it is not possible to do this except when you have access to the other domain to add the Access-Control-Allow-Origin: * header, to fix this go to this link.
2- but if it has the same domain or you have added Access-Control-Allow-Origin: * to the headers of your domain, you can do what you want like this:
var url = // url to my api
var e = angular.element("<iframe style='display:none' src=" + url + "></iframe>");
angular.element(document.body).append(e);
e[0].contentWindow.onload = function() {
$scope.$apply(function() {
$scope.exporting = false; // this will remove the mask/spinner
});
};
I have done this in all kinds of browsers.
I had problems with the iframe taking too long to load. The iframe registered as loaded while the request wasn't handled. I came up with the following solution:
JS
Function:
function iframeReloaded(iframe, callback) {
let state = iframe.contentDocument.readyState;
let checkLoad = setInterval(() => {
if (state !== iframe.contentDocument.readyState) {
if (iframe.contentDocument.readyState === 'complete') {
clearInterval(checkLoad);
callback();
}
state = iframe.contentDocument.readyState;
}
}, 200)
}
Usage:
iframeReloaded(iframe[0], function () {
console.log('Reloaded');
})
JQuery
Function:
$.fn.iframeReloaded = function (callback) {
if (!this.is('iframe')) {
throw new Error('The element is not an iFrame, please provide the correct element');
}
let iframe = this[0];
let state = iframe.contentDocument.readyState;
let checkLoad = setInterval(() => {
if (state !== iframe.contentDocument.readyState) {
if (iframe.contentDocument.readyState === 'complete') {
clearInterval(checkLoad);
callback();
}
state = iframe.contentDocument.readyState;
}
}, 200)
}
Usage:
iframe.iframeReloaded(function () {
console.log('Reloaded');
})
I've just noticed that Chrome is not always firing the load event for the main page so this could have an effect on iframes too as they are basically treated the same way.
Use Dev Tools or the Performance api to check if the load event is being fired at all.
I just checked http://ee.co.uk/ and if you open the console and enter window.performance.timing you'll find the entries for domComplete, loadEventStart and loadEventEnd are 0 - at least at this current time:)
Looks like there is a problem with Chrome here - I've checked it on 2 PCs using the latest version 31.0.1650.63.
Update: checked ee again and load event fired but not on subsequent reloads so this is intermittent and may possibly be related to loading errors on their site. But the load event should fire whatever.
This problem has occurred on 5 or 6 sites for me now in the last day since I noticed my own site monitoring occasionally failed. Only just pinpointed the cause to this. I need some beauty sleep then I'll investigate further when I'm more awake.

Prevent other scripts from setting window.title?

I'm working on a chrome extension, and I set window.title in the onload handler. It seems, though, that the page I'm modifying sets the document title dynamically as well. There's a huge collection of scripts being linked. Is there any way for me to prevent anyone else from modifying document.title or any of its variants, without knowing where the modification is coming from? Alternatively, is there a quick way for me to see where the change is coming from?
I had same problem, some external scripts are changed my page title by document.title = "..."
I've made own solution for it:
try {
window.originalTitle = document.title; // save for future
Object.defineProperty(document, 'title', {
get: function() {return originalTitle},
set: function() {}
});
} catch (e) {}
See the answer to how to listen for changes to the title element?. Notably:
function titleModified() {
window.alert("Title modifed");
}
window.onload = function() {
var titleEl = document.getElementsByTagName("title")[0];
var docEl = document.documentElement;
if (docEl && docEl.addEventListener) {
docEl.addEventListener("DOMSubtreeModified", function(evt) {
var t = evt.target;
if (t === titleEl || (t.parentNode && t.parentNode === titleEl)) {
titleModified();
}
}, false);
} else {
document.onpropertychange = function() {
if (window.event.propertyName == "title") {
titleModified();
}
};
}
};
This SO answer suggest a technique for how to listen for changes to the document title.
Perhaps you could use that technique to create a callback which changes the title back to whatever you want it to be, as soon as some other script tries to change it.

Detecting when an iframe gets or loses focus

What's the correct way of detecting when an iframe gets or loses focus (i.e. will or will not receive keyboard events)? The following is not working in Fx4:
var iframe = /* my iframe */;
iframe.addEventListener("focus", function() { /* never gets called */ }, false);
You can poll "document.activeElement" to determine if it matches the iframe. Polling isn't ideal, but it works:
function checkFocus() {
if(document.activeElement == document.getElementsByTagName("iframe")[0]) {
console.log('iframe has focus');
} else {
console.log('iframe not focused');
}
}
window.setInterval(checkFocus, 1000);
i know it's old, but i also had the same problem.
i ended up using this little pice of code:
$(document).on('focusout', function(){
setTimeout(function(){
// using the 'setTimout' to let the event pass the run loop
if (document.activeElement instanceof HTMLIFrameElement) {
// Do your logic here..
}
},0);
});
Turns out it's not really possible. I had to change the logic of my page to avoid the need of tracking if the iframe has focus.
How to check when an iframe has been clicked in or out of as well as hover-state.
Note: I would highly recommend you don't choose a polling method and go with an event driven method such as this.
Disclaimer
It is not possible to use the focus or blur events directly on an iframe but you can use them on the window to provide an event driven method of checking the document.activeElement. Thus you can accomplish what you're after.
Although we're now in 2018, my code is being implemented in GTM and tries to be cross browser compatible back to IE 11. This means there's more efficient code if you're utilizing newer ES/ECMAScript features.
Setup
I'm going to take this a few steps further to show that we can also get the iframe's src attribute as well as determine if it's being hovered.
Code
You would ideally need to put this in a document ready event, or at least encapsulate it so that the variables aren't global [maybe use an IIFE]. I did not wrap it in a document ready because it's handled by GTM. It may also depend where you place this or how you're loading it such as in the footer.
https://jsfiddle.net/9285tbsm/9/
I have noticed in the JSFiddle preview that it's already an iframe, sometimes you have to focus it first before events start to capture. Other issues can be that your browser window isn't yet focused either.
// Helpers
var iframeClickedLast;
function eventFromIframe(event) {
var el = event.target;
return el && el.tagName && el.tagName.toLowerCase() == 'iframe';
}
function getIframeSrc(event) {
var el = event.target;
return eventFromIframe(event) ? el.getAttribute('src') : '';
}
// Events
function windowBlurred(e) {
var el = document.activeElement;
if (el.tagName.toLowerCase() == 'iframe') {
console.log('Blurred: iframe CLICKED ON', 'SRC:', el.getAttribute('src'), e);
iframeClickedLast = true;
}
else {
console.log('Blurred', e);
}
}
function windowFocussed(e) {
if (iframeClickedLast) {
var el = document.activeElement;
iframeClickedLast = false;
console.log('Focussed: iframe CLICKED OFF', 'SRC:', el.getAttribute('src'), e);
}
else {
console.log('Focussed', e);
}
}
function iframeMouseOver(e) {
console.log('Mouse Over', 'SRC:', getIframeSrc(e), e);
}
function iframeMouseOut(e) {
console.log('Mouse Out', 'SRC:', getIframeSrc(e), e);
}
// Attach Events
window.addEventListener('focus', windowFocussed, true);
window.addEventListener('blur', windowBlurred, true);
var iframes = document.getElementsByTagName("iframe");
for (var i = 0; i < iframes.length; i++) {
iframes[i].addEventListener('mouseover', iframeMouseOver, true);
iframes[i].addEventListener('mouseout', iframeMouseOut, true);
}
I have solved this by using contentWindow instead of contentDocument.
The good thing about contentWindow is
it works also in case user clicks another window (another application) or another browser tab. If using activeElement, if user clicks away from the entire window to go to another application, then that logic still think the iframe is in focus, while it is not
and we don't need to poll and do a setInterval at all. This uses the normal addEventListener
let iframe = document.getElementsByTagName("iframe")[0];
// or whatever way you do to grab that iFrame, say you have an `id`, then it's even more precise
if(iframe){
iframeWindow = iframe.contentWindow;
iframeWindow.addEventListener('focus', handleIframeFocused);
iframeWindow.addEventListener('blur', handleIframeBlurred);
}
function handleIframeFocused(){
console.log('iframe focused');
// Additional logic that you need to implement here when focused
}
function handleIframeBlurred(){
console.log('iframe blurred');
// Additional logic that you need to implement here when blurred
}
This solution is working for me on both mobile and desktop:
;(function pollForIframe() {
var myIframe = document.querySelector('#my_iframe');
if (!myIframe) return setTimeout(pollForIframe, 50);
window.addEventListener('blur', function () {
if (document.activeElement == myIframe) {
console.log('myIframe clicked!');
}
});
})();
The solution is to inject a javascript event on the parent page like this :
var script = document.createElement('script');
script.type = 'text/javascript';
script.innerHTML =
"document.addEventListener('click', function()" +
"{ if(document.getElementById('iframe')) {" +
// What you want
"}});";
head.appendChild(script);
Here is the code to Detecting when an iframe gets or loses focus
// This code can be used to verify Iframe gets focus/loses.
function CheckFocus(){
if (document.activeElement.id == $(':focus').context.activeElement.id) {
// here do something
}
else{
//do something
}
}
A compact function that accepts callbacks you want to run when iframe gets or loses focus.
/* eslint-disable no-unused-vars */
export default function watchIframeFocus(onFocus, onBlur) {
let iframeClickedLast;
function windowBlurred(e) {
const el = document.activeElement;
if (el.tagName.toLowerCase() == 'iframe') {
iframeClickedLast = true;
onFocus();
}
}
function windowFocussed(e) {
if (iframeClickedLast) {
iframeClickedLast = false;
onBlur();
}
}
window.addEventListener('focus', windowFocussed, true);
window.addEventListener('blur', windowBlurred, true);
}
This might work
document.addEventListener('click', function(event) {
var frame= document.getElementById("yourFrameID");
var isClickInsideFrame = frame.contains(event.target);
if (!isClickInsideFrame ) {
//exec code
}
});

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