Develop Reference

Comparing strings using jQuery load function

Writing the code i am stuck with one thing. I am loading variable string through jQuery load function and there is where trouble starts. I want my code to check if string loaded through text file had any changes and if that is true make some actions. How do I set my variable as a string to compare it with the one in file? Part of the code
var follow, donate;
var auto_refresh = setInterval(function() {
follow = $('#followerid').load("../Muxy/most_recent_follower.txt");
donate = $('#donatorid').load("../Muxy/most_recent_donator.txt");
}, 100);
and then I want to make something like this:
someUpdateFunction() {
if($(#'followerid').get("innerHTML") != follow)
// actions (animations, div changes etc.)
}
That is probably totally wrong but I wasnt able to find any tips here. Thanks in advance

Try something like this:
$.get('../Muxy/most_recent_follower.txt', function (data) {
var followerid = $('#followerid').html();
if( followerid == data ){
// They are the same
}else{
// They are not the same
}
});
The .html() method will get the HTML inside #followerid. It sounds like that's what you want.

The jQuery.load function doesn't return the loaded file, it returns the element. Try out this:
var auto_refresh = setInterval(function() {
oldFollow = $('#followerid').html();
$('#followerid').load("../Muxy/most_recent_follower.txt");
oldDonate = $('#donatorid').html();
$('#donatorid').load("../Muxy/most_recent_donator.txt");
}, 100);
someUpdateFunction() {
if($('#followerid').html() !== oldFollow)
// actions (animations, div changes etc.)
}
}

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);

Firefox, javascript and iFrame performance with Jquery

I'm having a bit of a jquery javascript performance issue, specifically related to Firefox.
We have a set of vimeo embeds, and the ids are pulled in via a json file. On each click, a new video is displayed. After the video is played, the container is removed and the title cloud is put back in. After a certain number of rounds, Firefox performance seriously degrades and you get the "unresponsive script" error. This isn't happening on any other browsers. Furthermore, the profiler in FF doesn't seem to point to a root cause of the slowdown.
I believe this is caused by poor iframe performance and how FF handles iframes, but I'm not entirely sure about this. Nothing else I'm doing is anything too, mostly just stock jquery functions like empty(), remove(), prepend(), etc.
I have implemented a click counter which will just refresh the page after a certain amount of click throughs. This resolved the problem, but it's a hacky solution which I seriously dislike. I would love some ideas on the root cause of this and any advice on how to solve it.
Here's the link to the site and the specific portion mentioned:
http://www.wongdoody.com/mangles
This isn't all the code, but this is the part that gets called every click.
Also, I have tried just swapping out the src="" in the iframe, but performance still degrades.
EDIT: I can confirm this is not a memory leak, I used about:memory and with addons disabled in safe mode I'm getting decent memory usage:
359.11 MB ── private
361.25 MB ── resident
725.54 MB ── vsize
Something in the vimeo embed is slowing down the javascript engine, but it's not a memory leak. Also, this is confirmed by the fact that I can resolve the issue by just refreshing the page. If it was a memory leak I would have to close FF altogether.
function getIframeContent(vid) {
mangle_vid_id = vid;
return '<div class="vimeoContainerflex"><div class="vimeoContainer"><iframe class="vimeo" style="z-index:1;" width="100%" height="100%" frameborder="0" allowfullscreen="" mozallowfullscreen="" webkitallowfullscreen="" src="//player.vimeo.com/video/' + mangle_vid_id + '?api=1&title=0&color=89ff18&byline=0&portrait=0&autoplay=1"></iframe></div></div>';
}
function show_titles() {
$('.mangle-btn').hide();
$('.vimeoContainerflex').remove();
$('span.mangle').hide();
if ($('#mangle-titles').length < 1) {
$('#wongdoody').prepend(wd_titles_content);
}
$('#arrow').show();
if (clicks > 12) {
location.reload();
}
$('#mangle-titles span').click(function() {
clicks = clicks + 1;
$('#mangle-wrapper').remove();
var vidID = $(this).attr('data-id');
if ($('.vimeoContainer').length < 1) {
if (vidID == "home") {
$('#wongdoody').prepend(getIframeContent(getRandom()));
} else {
$('#wongdoody').prepend(getIframeContent(vidID));
}
}
$('#arrow').hide();
vimeoAPI();
});
$('#mangle-titles span').not('noscale').each(function() {
var _this = $(this);
var classname = _this.attr('class');
var scaleNum = classname.substr(classname.length - 2);
var upscale = parseInt(scaleNum);
var addition = upscale + 5;
var string = addition.toString();
_this.hover(
function() {
_this.addClass('scale' + string);
},
function() {
_this.removeClass('scale' + string);
}
);
});
}
function vimeoAPI() {
var player = $('iframe');
var url = window.location.protocol + player.attr('src').split('?')[0];
var status = $('.status');
// Listen for messages from the player
if (window.addEventListener) {
window.addEventListener('message', onMessageReceived, false);
} else {
window.attachEvent('onmessage', onMessageReceived, false);
}
// Handle messages received from the player
function onMessageReceived(e) {
var data = JSON.parse(e.data);
switch (data.event) {
case 'ready':
onReady();
break;
case 'finish':
onFinish();
break;
}
}
// Helper function for sending a message to the player
function post(action, value) {
var data = {
method: action
};
if (value) {
data.value = value;
}
var message = JSON.stringify(data);
if (player[0].contentWindow != null) player[0].contentWindow.postMessage(data, url);
}
function onReady() {
post('addEventListener', 'finish');
}
function onFinish() {
setTimeout(show_titles, 500);
}
}

Part of you're problem may be the fact that you keep adding more and more click-handlers to the spans. After each movie ends the onFinish function calls show_titles again, which attaches a new (=additional) click-handler to the $('#mangle-titles span') spans. jQuery does not remove previously attached handlers.
Try splitting the show_titles function into two. init_titles should be called only once:
function init_titles() {
if ($('#mangle-titles').length < 1) {
$('#wongdoody').prepend(wd_titles_content);
}
$('#mangle-titles span').click(function() {
$('#mangle-wrapper').remove();
var vidID = $(this).attr('data-id');
if ($('.vimeoContainer').length < 1) {
if (vidID == "home") {
$('#wongdoody').prepend(getIframeContent(getRandom()));
} else {
$('#wongdoody').prepend(getIframeContent(vidID));
}
}
$('#arrow').hide();
vimeoAPI();
});
$('#mangle-titles span').not('noscale').each(function() {
var _this = $(this);
var classname = _this.attr('class');
var scaleNum = classname.substr(classname.length - 2);
var upscale = parseInt(scaleNum);
var addition = upscale + 5;
var string = addition.toString();
_this.hover(
function() {
_this.addClass('scale' + string);
},
function() {
_this.removeClass('scale' + string);
}
);
});
}
function show_titles() {
$('.mangle-btn').hide();
$('.vimeoContainerflex').remove();
$('span.mangle').hide();
$('#arrow').show();
}

I'd recommend trying to re-use the iframe instead of wiping and re-adding. Failing that, I think you may be out of luck. Your method of closing the iFrame is fine; your browser that it's running in is not.

You're overloading window with eventListeners. Each time a user clicks a video, you're attaching an event to window that fires every time you're receiving a message.
You can easily check this by adding console.log("Fire!"), for instance, at the beginning of onMessageReceived. You'll see that this function gets triggered an awful number of times after the user has performed some clicks on videos.
That surely has an impact on performance.
Hope this helps.

Javascript stops when loading from cache manifest in webapp

My javascript code stops when the side loads from the cache manifest in the Fullscreen WebApp Mode(iPad3/iOS6).
This has the consequence that you cant do anything in the first 5 seconds. After that you can use the site as normal.
1) Why does the JavaScript Code stop? (Event Problem?)
2) How can i fix it?
Involved is:
jquery-1.8.2.min.js
EDIT:
I have experimented and found out that the JavaScript code runs normally after the event onNoUpdate and onUpdateReady. Until these two events are initiated, it passes a large time. So this is not a option.
EDIT2:
`<script type="text/javascript">
$(document).bind('touchmove', false);
$(document).ready(function () {
applicationCache.onupdateready = function () {
if (confirm("Ihre Applikation wurde aktualisiert. Soll die Darstellung neu geladen werden?")) {
window.location.reload();
}
}
applicationCache.onnoupdate = function () {
}
var a = document.getElementsByTagName("a");
for (var i = 0; i < a.length; i++) {
if (a[i].className.match("noeffect")) {
// Here happens nothing
}
else {
a[i].onclick = function () {
load();
window.location = this.getAttribute("href");
return false;
};
}
}
}
);`

Try inserting some logs in key spots to find out exactly where in the code the pause happens. Usually when you narrow it down enough, the answer becomes clear.

How to smooth a jQuery script that takes time to execute?

I have a jQuery script that searches in the DOM and shows the results in a list.
There is a simplified version of the script here: http://jsfiddle.net/FuJta/1/
There is usually a large number of results, so the script can take a while to execute. (In the example above, this is simulated with a function that delays the script). So if you type too fast in the searchbox, the script prevents you from typing, and it feels bad.
How could I change my script so that you can type freely, and the results show up when they are ready. I want something like the facebook search : if you type too fast, the results are just delayed, but you can still type.
Html
<p>Type in foo, bar or baz for searching. It works, but it is quite slow.</p><br/>
<input type="text" id="search"/>
<div id="container" style="display:none">
<div class="element">foo</div>
<div class="element">bar</div>
<div class="element">baz</div>
</div>
<div id="results">
</div>​
Javascript
$(function() {
function refreshResults() {
var search = $('#search').val();
var $filtered = $('#container .element').clone().filter(function() {
var info = $(this).text();
return info.toLowerCase().indexOf(search) >= 0;
});
$('#results').empty();
$filtered.each(function() {
$('#results').append($(this));
});
}
// simulating script delay
function pausecomp(millis) {
var date = new Date();
var curDate = null;
do {
curDate = new Date();
}
while (curDate - date < millis);
}
$('#search').keyup(function() {
pausecomp(700);
refreshResults();
});
});​
One solution could to refresh the results only when pressing enter. This way, the delay for searching the results feels ok. But I would prefer if I just delay the results and let the user freely type.

You should perform a search like this using asynchronous techniques. No doubt Facebook uses some sort of AJAX to request search results - which means getting the results from the server. This will help prevent the UI 'freeze' that you are currently experiencing.
Here is a very simple example of what you can try (it uses JQuery for the AJAX requests):
var searchInProgress = false;//used to work out if a search is in progress
var searchInQueue = false;//used to flag if the input data has changed
function getSearchResults(searchText){
if (searchInProgress ) {
searchInQueue = true;
return;
}
searchInProgress = true;
searchInQueue = false;
$.getJSON("URL",//URL to handle AJAX query
{ searchText: searchText},//URL parameters can go here
function (data) {
//handle your returned data here
searchInProgress = false;
if (searchInQueue){//text has changed, so search again
getSearchResults();
}
});
}
$('#search').keyup(function() {
getSearchResults($(this).val());
});
A few things to note: It is probably a good idea to handle failed AJAX requests to ensure you can reset the searchInProgress flag as needed. Also, you can add delays after the keyup as desired, but this all depends on how you want it too work.

From How to delay KeyPress function when user is typing, so it doesn't fire a request for each keystroke? :
var timeoutId = 0;
$('#search').keyup(function () {
clearTimeout(timeoutId); // doesn't matter if it's 0
timeoutId = setTimeout(refreshResults, 100);
});
It does what I want indeed.

Here's a solution that divides the search process into steps, returning flow to the browser during the process to allow the UI to respond.
$(function() {
function searchFunc($element,search) {
var info = $element.text();
return info.toLowerCase().indexOf(search) >= 0;
}
var searchProcessor = null;
function restartSearch() {
console.log('Restarting...');
// Clear previous
if (searchProcessor != null) {
clearInterval(searchProcessor);
}
$('#results').empty();
// Values for the processor
var search = $('#search').val();
var elements = $('#container .element').get();
console.log('l:',elements,elements.length);
// Start processing
searchProcessor = setInterval(function() {
if (elements.length == 0) {
// Finished searching all elements
clearInterval(searchProcessor);
searchProcessor = null;
console.log('Finished.');
} else {
console.log('Checking element...');
var $checkElement = $(elements.shift());
if (searchFunc($checkElement, search)) {
$('#results').append($checkElement.clone());
}
}
}, 10);
}
$('#search').keyup(function() {
restartSearch()
});
});
It only processes one element each time. That should probably be increased so it handles perhaps 10 or 100 each time around, but the important point is that the work is divided into chunks.
This solution should also be faster than the original because it doesn't clone() everything, only the elements that were matched.