Develop Reference

Is there any callback function after 'Friends List' loaded in cometchat?

I have integrated 'Embed Layout' comet chat on my site. Now I want to open particular friend chat on page load.
In the documentation, I've found below code to do the same. REF : Documentation Link
jqcc.cometchat.chatWith(user_id)
I have included in custom js from admin panel. However, it is showing below error in console
jqcc.cometchat.chatWith is not a function
But If I use same after friends list loaded from the console it is working fine.
How can I fix this issue?

Currently for time being I have fixed this issue by adding below code in custom js
var first_chat_loaded = false;
var first_chat = setInterval(function () {
try {
if (first_chat_loaded === false) {
// Function to get other user id defined in parent html page
var other_userid = parent.get_other_user_id();
jqcc.cometchat.chatWith(other_userid);
first_chat_loaded = true;
clear_first_load();
}
} catch (e) {
}
}, 1000);
function clear_first_load() {
clearInterval(first_chat);
}
Please let me know, If there is any proper way to do the same.

Kindly make use of this code snippet for the above mentioned issue
var checkfn = setInterval(
function(){
if(typeof jqcc.cometchat.chatWith == 'function'){
jqcc.cometchat.chatWith(user_id);
clearInterval(checkfn);
}
},
500);

jQuery each not functioning correctly

I have a slider with 10 slider elements. However, only 7 out of 10 elements are rendered, given my data structure contains 20 sets. The site is hosted here
The code in question
function populateCarousell(cdata) {
var x = 0; //debug
jQuery(".wslide-slides .wslide-slide").each(function() {
var single = cdata.shift();
var jcurrSlide = jQuery(this);
jcurrSlide.find(".wslide-caption-text").text(single.title);
jcurrSlide.find("a").attr('href', "https://carousell.com/p/" +single.id);
jcurrSlide.css({'background-image':Base64.decode('dXJs')+'('+single.primary_photo_full_url+')'});
jcurrSlide.css({'background-image':'contain'});
jcurrSlide.css({'background-position':'50% 50%'});
jcurrSlide.css({'background-repeat': 'no-repeat'});
x++; //debug
jcurrSlide.find(".wslide-slide-inner2").removeAttr('style').find("img").css({'display':'none'});
});
alert(x); //Outputs 7
}
which is activated by (to ensure page fully loaded)
function caroDataCallback(data) {
if(document.readyState != "complete" ) {
setTimeout(function() { caroDataCallback(data); }, 2000);
}
else{
populateCarousell(data);
}
}
Upon examination in Chrome, the results is

That's because your page is not fully loaded when you call populateCarousell(cdata) function in your javascript file. Try instead of using $(document).ready(), use the $(document).load() to make sure all the images are loaded before you initiate your carousel.
Update: Use $(window).on('load', function() { .. }); instead.
Hope this helps.

'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.

Javascript window.print() issue on newly appended HTML

The problem is that the new content will not print (a few more elements).
When the user clicks my print link then I add more html to the document before window.print() is called.
I use ajax to fetch more chapters for a book before printing.
Code:
Print initialized:
var afterPrint = function () {
var timer = setInterval(function () {
afterContentPrint(); // Cleanup html (restore to initial state)
clearInterval(timer);
}, 900);
}
//window.onbeforeprint = beforePrint;
window.onafterprint = afterPrint;
Event print click:
$("#print-test").click(function (e) {
e.preventDefault();
beforeContentPrint(); // ajax call for additional content, finishing by calling window.print()
});
In function beforeContentPrint():
var jqxhr = $.ajax({
type: "GET",
url: bookURL,
success: function(data) {
.....
.....
$(article).each(function () {
parent.append(article);
});
},
complete: function() {
var timer = setInterval(function () {
    window.print();
}, 900);
}
}
The new content is visibly added to the HTML document, so it should work. But only the initial content (before ajax call) is picked up for print.
This solution is for IE and Firefox (onbeforeprint and onafterprint).
Using window.matchMedia('print') seems to work fine in Chrome with this logic.

I don't know why this is happening but there is a working around in mozilla docs; printing a hidden iframe, then you open more chapters of the book with no need to shows up.
Here the link https://developer.mozilla.org/en-US/docs/Printing
Here the code:
<!doctype html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>MDN Example</title>
<script type="text/javascript">
function closePrint () {
document.body.removeChild(this.__container__);
}
function setPrint () {
this.contentWindow.__container__ = this;
this.contentWindow.onbeforeunload = closePrint;
this.contentWindow.onafterprint = closePrint;
this.contentWindow.print();
}
function printPage (sURL) {
var oHiddFrame = document.createElement("iframe");
oHiddFrame.onload = setPrint;
oHiddFrame.style.visibility = "hidden";
oHiddFrame.style.position = "fixed";
oHiddFrame.style.right = "0";
oHiddFrame.style.bottom = "0";
oHiddFrame.src = sURL;
document.body.appendChild(oHiddFrame);
}
</script>
</head>
<body>
<p><span onclick="printPage('externalPage.html');" style="cursor:pointer;text-decoration:underline;color:#0000ff;">Print external page!</span></p>
</body>
</html>

1st Attempt : try putting asyn:false in the ajax request of beforeContentPrint, so that the elements will be added first then the print will be called.
var jqxhr = $.ajax({
type: "GET",
url: bookURL,
async:false,
success: function(data) {
.....
.....
$(article).each(function () {
parent.append(article);
});
},
complete: function() {
var timer = setInterval(function () {
window.print();
}, 900);
}
}
2ndAttempt: Take a look Here how to force execution of one function after another.
Hope this helps.

As the elements added aren't shown it can be a little hard to pinpoint the exact problem, but adding elements via appending/inserting into document doesn't always work that well for all browsers and in worst case you will need to add those elements manually by code (document.createElement(), appendChild() etc.).
In an attempt to create a work-around you can try to use MutationObservers to track changes for your article element which can hopefully help you trigger print when DOM is updated properly. The support is fairly good in new browsers (you may have to use prefix in some, f.ex. WebKitMutationObserver) and for older browsers you can provide a fallback - which of course then only get you so far.
This will monitor a target element for changes and fire a callback.
Generic example based on this article:
var article = document.querySelector('#articleID'),
doPrint = false, // must be available in global/parent scope
o,
useFallback = (typeof MutationObserver !== 'undefined');
if (!useFallback) {
o = new MutationObserver(function(mutations) {
mutations.forEach(function(mutation) {
// you can do additional filtering here
// using the mutation object (.name, .type, ...)
if (doPrint) {
doPrint = false;
window.print();
}
});
});
var cfg = { attributes: true, childList: true, characterData: true };
o.observe(article, cfg);
}
Now that the observer is running you can do this modification in your success callback:
var timer; // keep track of setTimeout so we can cancel it
success: function(data) {
...
...
$(article).each(function () {
parent.append(article);
});
// after last element is added, add a "dummy" element
doPrint = true;
if (useFallback) {
// fallback to setTimeout or other solution
}
else {
parent.append('<br />');
}
}
I made an online demo here which sets up the observer and adds some elements. Open console to see actions. The demo is probably too limited data-wise to simulate your situation but can be useful to see the process.
The mechanism used here for triggering print dialog itself can be discussed if is the best - I just provide one for sake of example.
But you can see the observer is triggered when something is added to article. This way you know the DOM has been updated and it should be available for printing. Only the last element added need to trigger the print, hence the doPrint flag.
If you still have no success you will need to consider adding the elements manually the code way or perhaps predefine some elements that you inject when needed (as said, without knowing the full scenario here it has to be with the guess).

It looks like the setInterval, clearInterval is what is messing you up. Change to a setTimeout and get rid of the clearInterval in your afterprint function. I made a fiddle that works in FF and IE9. Fiddle
complete: function() {
var timer = setTimeout(function () {
window.print();
}, 900);
}

jQuery .ready in a dynamically inserted iframe

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>