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Flexslider breaks jQuery accordion [duplicate]

I have a test page to better explain my problem. I have several items on a list (they're images on the test page); when I click on one of them, a corresponding slideshow, using flexslider, sldes down.
The problem is that, on page load, the slideshow shows all slides at once, at a much smaller size than intended. But then, if I switch the focus from the window (i.e. switch between browser tabs or move to another program and come back), the slideshow is now working and the slides are the proper size. This happens in mobile devices too.
When I check with firebug, there's an element.style rule applying to ul.slides:
transform: translate3d(-89px, 0px, 0px);
Which hides one of the slides. Additionally, there's another rule for the list items inside ul.slides that gives them their initial width, which is not even the same for all sliders so I don't understand where it is coming from.
Can someone take a look and suggest a fix? I've tried overriding the element.style rule but so far unsuccessfully.

I think I've figured it out, in principal at least...
.flexslider{display:none;} seems throw off the re-size function of Flexslider.
You could just remove it, but that makes for some ugly loading.
To avoid said ugly loading I put together a quick, work-around- jsFiddle
$(document).ready(function(){
$(".flexslider").css('display','block').slideUp();
});
There's a still a quick glitch while loading, but hopefully it will at least steer you in the right direction.
Another method I played with a bit was to try and force the re-size function like so-
$(".client").click(function () {
$('.flexslider').resize(); // Problematic but promising
var project = this.id;
var project_id = '#' + project + '-project';
var elem = $(".flexslider:visible").length ? $(".flexslider:visible"): $(".flexslider:first");
elem.slideUp('slow', function () {
$(project_id).slideDown('slow');
});
});
This sort of solved the mini-picture issue, but was spotty at best.

Improving iScroll performance on a large table

I'm updating a table header and its first column positions programatically based on how the user scrolls around to keep them aligned.
The issue I'm experiencing is that as soon as my data sets gets big enough, the scrolling gets more and more choppy/less smooth.
The relevant code is at the very bottom of the fiddle:
iScroll.on('scroll', function(){
var pos = $('#scroller').position();
$('#pos').text('pos.left=' + pos.left + ' pos.top=' + pos.top);
// code to hold first row and first column
$('#scroller th:nth-child(1)').css({top: (-pos.top), left: (-pos.left), position:'relative'});
$('#scroller th:nth-child(n+1)').css({top: (-pos.top), position:'relative'});
// this seems to be the most expensive operation:
$('#scroller td:nth-child(1)').css({left: (-pos.left), position:'relative'});
});
I know that this can be written a lot more efficent by caching the elements and so on. For example, I have tried saving the elements in to an array and updating their position in a more "vanilla" fashion:
headerElements[i].style.left = left + 'px'; // etc...
No matter how fast I make the callback, I'm still not happy about the result. Do you have any suggestions?
https://jsfiddle.net/0qv1kjac/16/

Just use ClusterizeJS! It can handle hundreds of thousands of rows and was built exactly for this purpose.
How does it work, you ask?
The main idea is not to pollute DOM with all used tags. Instead of that - it splits the list to clusters, then shows elements for current scroll position and adds extra rows to top and bottom of the list to emulate full height of table so that browser shows scrollbar as for full list

To be able to handle big amounts of data you need data virtualization. It has some restrictions, though.
First you need to decide the size of a view port. Let's say you want to render 10 items in a row and 20 items in column. It would be 10x20 items then. In you fiddle it's div with id wrapper.
Then you need to know total amount of data you have. From your fiddle it would be 100x100 items. And, also you need to know height and width of a item (cell). Let's take 40x120 (in px).
So div#wrapper is a view port, it should have fixed sized like 10x20 items. Then you need to set up correct width and height for table. The height of table would be equal to total amount of data in column including head by item height. Width for table would be total amount of items in single row by item width.
Once you set up these, div#wrapper will receive horizontal and vertical scrolls. Now you able to scroll left and bottom, but it will be just empty space. However this empty space is able to hold exact amount of data you have.
Then you need to take scroll data left and top (position), which comes in pixels and normalize it to amount of items, so you could know not how many pixels you've scrolled, but how many items you've scrolled(or rows if we scroll from top to bottom).
It could be done by division of pixels scrolled on item height. For example, you scrolled to left by 80px, that's 2 items. It means these items should be invisible because you've scrolled past them. So you know that you scrolled past 2 items, and you know that you should see 10 items in a row. That means you take your data array which has data for row with 100 items, and slice it like this:
var visibleItems = rowData.slice(itemsScrolled, itemsScrolled + 10);
It will give you items which should be visible in viewport at current scroll position. Once you have these items you need to construct html and append it to table.
Also on each scroll event you need to set top and left position for tbody and thead so they would move with scroll, otherwise you will have your data, but it will be at (0; 0) inside a viewport.
Anyway, code speaks thousand of words, so here's the fiddle: https://jsfiddle.net/Ldfjrg81/9/
Note, that this approach requires heights and widths to be precise, otherwise it will work incorrectly. Also if you have items of different sizes, this also should be taken into consideration, so better if you have fixed and equal sizes of items. In jsfiddle, I commented out the code which forces first column to stay in place, but you can render it separately.
It's a good solution to stick to some library as suggested in comments, since it handles a lot of cases for you.
You can make rendering even faster if use react.js or vue.js

This won't be the answer your are looking for but here's my 2 cents anyway.
Javascript animation (especially given the amount that the DOM has to render) will never be as smooth as you want it. Even if you could get it smooth on your machine, chances are that it will vary drastically on other peoples (Older PC's, Browsers etc).
I would see 2 options if I were to tackle this myself.
Go old school and add a horizontal and vertical scrollbar. I know it's not a pretty solution but it would work well.
Only render a certain amount of rows and discard those off screen. This could be a bit complicated but in essence you would render say 10 rows. Once the user scrolls to a point where the 11th should be there, render that one and remove the 1st. You would pop them in and out as needed.
In terms of the actual JS (you mentioned putting elements in to an array), that isn't going to help. The actual choppyness is due to the browser needing to render that many elements in the first place.

You're experiencing choppy / non-smooth scrolling because the scroll event fires at a very high pace.
And every time it fires you're adjusting the position of many elements: this is expensive and furthermore until the browser has completed the repaint it's unresponsive (here the choppy scrolling).
I see two options:
Option number one: display only the visible subset of the whole data set (this has been already suggested in another answer so I won't go futher)
Option number two (easier)
First, let animations on left and top css changes occurr via transitions. This is more efficient, is non-blocking and often let the browser take advantage of the gpu
Then instead of repeteadly adjust left and top, do it once a while; for example 0.5 seconds. This is done by the function ScrollWorker() (see code below) that recalls itself via a setTimeout().
Finally use the callback invoked by the scroll event to keep the #scroller position (stored in a variable) updated.
// Position of the `#scroller` element
// (I used two globals that may pollute the global namespace
// that piece of code is just for explanation purpose)
var oldPosition,
newPosition;
// Use transition to perform animations
// You may set this in the stylesheet
$('th').css( { 'transition': 'left 0.5s, top 0.5s' } );
$('td').css( { 'transition': 'left 0.5s, top 0.5s' } );
// Save the initial position
newPosition = $('#scroller').position();
oldPosition = $('#scroller').position();
// Upon scroll just set the position value
iScroll.on('scroll', function() {
newPosition = $('#scroller').position();
} );
// Start the scroll worker
ScrollWorker();
function ScrollWorker() {
// Adjust the layout if position changed (your original code)
if( newPosition.left != oldPosition.left || newPosition.top != oldPosition.top ) {
$('#scroller th:nth-child(1)').css({top: (-newPosition.top), left: (-newPosition.left), position:'relative'});
$('#scroller th:nth-child(n+1)').css({top: (-newPosition.top), position:'relative'});
$('#scroller td:nth-child(1)').css({left: (-newPosition.left), position:'relative'});
// Update the stored position
oldPosition.left = newPosition.left;
oldPosition.top = newPosition.top;
// Let animation complete then check again
// You may adjust the timer value
// The timer value must be higher or equal the transition time
setTimeout( ScrollWorker, 500 );
} else {
// No changes
// Check again after just 0.1secs
setTimeout( ScrollWorker, 100 );
}
}
Here is the Fiddle
I set the Worker pace and the transition time to 0.5 secs. You may adjust the value with higher or lower timing, eventually in a dinamic way based on the number of elements in the table.

Yes! Here are some improvements to the code from your JS Fiddle. You can view my edits at: https://jsfiddle.net/briankueck/u63maywa/
Some suggested improvements are:
Switching position:relative values in the JS layer to position:fixed in the CSS layer.
Shortening the jQuery DOM chains, so that the code doesn't start at the root element & walk all the way through the dom with each $ lookup. The scroller is now the root element. Everything uses .find() off of that element, which creates shorter trees & jQuery can traverse those branches faster.
Moving the logging code out of the DOM & into the console.log. I've added a debugging switch to disable it, as you're looking for the fastest scrolling on the table. If it runs fast enough for you, then you can always re-enable it to see it in the JSFiddle. If you really need to see that on the iPhone, then it can be added into the DOM. Although, it's probably not necessary to see the left & top position values in the iPhone.
Remove all extraneous $ values, which aren't mapped to the jQuery object. Something like $scroller gets confusing with $, as the latter is the jQuery library, but the former isn't.
Switching to ES6 syntax, by using let instead of var will make your code look more modern.
There is a new left calculation in the <th> tag, which you'll want to look at.
The iScroll event listener has been cleaned up. With position:fixed, the top <th> tags only need to have the top property applied to them. The left <td> tags only need to have the left property applied to them. The corner <th> needs to have both the top & left property applied to it.
Remove everything that's unnecessary, like the extraneous HTML tags which were used for logging purposes.
If you really want to go more vanilla, change out the .css() methods for the actual .style.left= -pos.left + 'px'; and .style.top= -pos.top + 'px'; properties in the JS code.
Try using a diff tool like WinMerge or Beyond Compare to compare the code from your version to what's in my edits, so that you can easily see the differences.
Hopefully, this will make the scrolling smoother, as the scroll event doesn't have to process anything that it doesn't need to do... like 5 full DOM traversing look-ups, rather than 3 short-tree searches.
Enjoy! :)
HTML:
<body>
<div id="wrapper">
<table id="scroller">
<thead>
</thead>
<tbody>
</tbody>
</table>
</div>
</body>
CSS:
/* ... only the relevant bits ... */
thead th {
background-color: #99a;
min-width: 120px;
height: 32px;
border: 1px solid #222;
position: fixed; /* New */
z-index: 9;
}
thead th:nth-child(1) {/*first cell in the header*/
border-left: 1px solid #222; /* New: Border fix */
border-right: 2px solid #222; /* New: Border fix */
position: fixed; /* New */
display: block; /*seperates the first cell in the header from the header*/
background-color: #88b;
z-index: 10;
}
JS:
// main code
let debug = false;
$(function(){
let scroller = $('#scroller');
let top = $('<tr/>');
for (var i = 0; i < 100; i++) {
let left = (i === 0) ? 0 : 1;
top.append('<th style="left:' + ((123*i)+left) + 'px;">'+ Math.random().toString(36).substring(7) +'</th>');
}
scroller.find('thead').append(top);
for (let i = 0; i < 100; i++) {
let row = $('<tr/>');
for (let j = 0; j < 100; j++) {
row.append('<td>'+ Math.random().toString(36).substring(7) +'</td>');
}
scroller.find('tbody').append(row);
}
if (debug) console.log('initialize iscroll');
let iScroll = null;
try {
iScroll = new IScroll('#wrapper', {
interactiveScrollbars: true,
scrollbars: true,
scrollX: true,
probeType: 3,
useTransition:false,
bounce:false
});
} catch(e) {
if (debug) console.error(e.name + ":" + e.message + "\n" + e.stack);
}
if (debug) console.log('initialized');
iScroll.on('scroll', function(){
let pos = scroller.position();
if (debug) console.log('pos.left=' + pos.left + ' pos.top=' + pos.top);
// code to hold first row and first column
scroller.find('th').css({top:-pos.top}); // Top Row
scroller.find('th:nth-child(1)').css({left:-pos.left}); // Corner
scroller.find('td:nth-child(1)').css({left:-pos.left}); // 1st Left Column
});
});

Is it necessary that you create your own scroller? Why don't you just style the data in HTML/CSS and just use the overflow attribute? JavaScript needs work on it's ability to adjust framerates. I was using your jFiddle earlier and it worked just fine with the native overflow handler.

Found this in the manual. Probably not what you wanna hear but it's the way it is:
IScroll is a class that needs to be initiated for each scrolling area. There's no limit to the number of iScrolls you can have in each page if not that imposed by the device CPU/Memory.
Try to keep the DOM as simple as possible. iScroll uses the hardware compositing layer but there's a limit to the elements the hardware can handle.

The reason the performance degradation is happening is that your scroll event handler is firing again and again and again instead of waiting for a reasonable and imperceptible interval.
The screenshot shows what happened when I tracked how many times the event handler fired, while scrolling for just a few seconds. The computationally-heavy event handler was fired over 600 times!!! This is more than 60 times per second!!!
It may seem counter-intuitive, but reducing the frequency that the table is updated will vastly increase perceived response times. If your user scrolls for fraction of a second, about 150 milliseconds, and the table is updated ten times, freezing the display during the scrolling, the net result is far worse than if the table were updated only three times and moved fluidly rather than freezing. It is just wasted processor burn to update more times than the browser can handle without freezing.
So, how do you make an event handler that fires at a maximum frequency, for example 25 times per second, even it is triggered much more often, like 100 times per second?
The naive way of doing it is to run a setInterval event. That is better, but horribly inefficient as well. There is a better way of doing it, by setting a delayed event handler, and clearing it on subsequent invocations before setting it again, until the minimum time interval has passed. This way it only runs no more often than at the maximum desired frequency. This is one major case for why the ``clearInterval'' method was invented.
Here is live working code:
https://jsfiddle.net/pgjvf7pb/7/
Note: when refreshing continuously like this, the header column may appear out of position.
I advise to do the update only when the scrolling has paused for about 25ms or so, rather than continuously. This way, it appears to the user that the header column is dynamically calculated as well as being fixed in place, because it appears instantly after scrolling rather than seeming to scroll with the data.
https://jsfiddle.net/5vcqv7nq/2/
The logic is like this:
variables outside your event handler
// stores the scrolling operation for a tiny delay to prevent redundancy
var fresh;
// stores time of last scrolling refresh
var lastfresh = new Date();
operations inside your event handler
// clears redundant scrolling operations before they are applied
if (fresh) clearTimeout(fresh);
var x = function() {
// stores new time of scrolling refresh
lastfresh = new Date();
// perform scrolling update operations here...
};
// refresh instantly if it is more than 50ms out of date
if (new Date() - lastfresh > 50) x();
// otherwise, pause for half of that time to avoid wasted runs
else fresh = setTimeout(x, 25);
Demo: https://jsfiddle.net/pgjvf7pb/7/
Once again, I recommend that you remove the line of code that refreshes the data instantly, and the else condition after that, and simply use one line
fresh = setTimeout(x, 25);
This will appear to instantly calculate the header column the moment any scrolling is finished, and saves even more operations. My second link to JS Fiddle shows what this looks like, here: https://jsfiddle.net/5vcqv7nq/2/

Animating SVG elements with GSAP

I am tasked with creating an interactive SVG infographic with few slides for a browser game, it has 5 steps total. When you click prev / next buttons or a specific step, the whole svg should animate itself to the correct step.
In terms of code, this is what I have:
function Slide() {
// Cache all top-level svg elements for later use
this.el = $('svg#betfair-slider');
this.hands = this.el.find('#hands_8_');
this.cardsDesk = this.el.find('g#center-cards');
this.textContainer = $('.step-text');
// Use a shared timeline across all slides, so there are no overlapping tweens
this.tween = new TimelineLite();
}
function Slide2 () {
// Inherit from the main slide
Slide.call(this);
// each slide has its own supporting explanatory text
this.html = [
'<h3>Preflop</h3>',
'<p>Amet sit lorem ipsum dolar</p>'
].join('');
// the main openslide method
this.openSlide = function() {
// find the cards that need to be animated for this specific slide
var cards = this.hands.find('.card');
// fade out each card
this.tween.staggerTo(cards, 0.2, { opacity: 0 }, 0.2);
// Render supporting text
this.textContainer.html(this.html);
};
}
Here are the cards I am trying to get:
I am able to fetch them using the this.hands.find('.card'); jquery method (I can see them in the console), but I just can't animate them. I have tried animating different attributes (opacity, x, y, left, etc), but nothing happens - nothing moves on the screen.
I am able to do this.hands.find('.card').hide() and change the css using jQuery, but why TimelineLite doesn't work here? I also tried this approach:
var cards = this.hands.find('.card');
for (var i = cards.length - 1; i >= 0; i -= 1) {
var card = cards[i];
this.tween.to(card, 0.2, { opacity: 0 });
}
But still no success... The interesting thing is that when I attach an onComplete callback on the tweens, THEY ARE fired, but absolutely nothing moves on the screen. You can check out everything here.
Thanks for the help in advance, any suggestions are more then welcome.

I think you might be misunderstanding how timelines work (or perhaps I'm misunderstanding your intent). Like all tweens, timelines start playing immediately by default. So if you're using one timeline and shoving all your tweens in there based on user interaction (meaning time elapses between when you create it and when you populate it...and populate it more...), its playhead will already have advanced. I bet that's causing your tweens to jump to their end state almost immediately. That's not a bug - it's how things are supposed to work, although there's some logic in GSAP to adjust behavior in certain circumstances to make it more intuitive.
I see several options:
Just use TweenMax instead of a TimelineLite. Like TweenMax.staggerTo(...) and TweenMax.to(...).
Or just create a TimelineLite for each user interaction (instead of one for ALL of your tweens globally). That way you'll populate it right away and it'll play as you expected.
You could use one global timeline if you really want to, but you might just need to manage its playhead if you're going to be inserting tweens on each user interaction rather than all at once.
If you're still having trouble, don't hesitate to post in the GSAP-dedicated forums at http://greensock.com/forums/ and it's be super helpful if you included a codepen or jsfiddle reduced test case so that we can tinker and very quickly see what's going on and how the changes affect the result.
Happy tweening!

Moving content blocks using javascript for responsive design

I'm working on a highly responsive website at the moment and I hit 2 areas where certain blocks of content need to move to others areas of the site. It would not be possible to do so purely with CSS. I suppose I could relatively reposition the blocks but as the dimensions change this isn;t really possible.
The option I am thinking of is, when a media query gets triggered, to then pull a block out of the page and append it in elsewhere where I need it.
I realise this is not ideal bit what I am wanting to ask is if this is a reasonable thing to so.
I know some of you may say reorder some of the markup but that is not possible. As stated above, I know falling back to javascript is not ideal but it would suit this and I don't particularly wish to duplicate content just so I can avoid the use of javascript.
Flexbox would be perfect but support is not where I want it to be currently for me to use that.
What do people here think? Any other solutions?

The right way is to listen to media queries using MediaQueryList:
var mql = window.matchMedia("(max-width: 320px)");
mql.addListener(function(event) {
if(event.matches) {
// Window width is less than or equal to 320, do something cool.
} else {
// Window width is more than 320, do something else.
}
});
The events will trigger when the query is either met or 'unmet'.
Alternatively, you can listen to a resize event, but note your function will get triggered for every new dimension. (Assuming jQuery in the code below.)
$(window).resize(function() {
if($(window).width() <= 320) {
// Window width is less than or equal to 320, do something cool.
} else {
// Window width is more than 320, do something else.
}
});
Like you said yourself though, using JS to make your layout responsive is generally NOT advisable. You can never assume all your users have JS enabled and all goes well.
I would rather see you solve this by restructuring your HTML and CSS. If the content layout has to change a lot, try outputting a block of content in two different places in your HTML and toggling visibility with CSS media queries (setting one to display:none; and the other to display:block;). You should be able to solve most responsive layout issues by rethinking your website structure.

Others looking for a solution may be interested in the Bootstrap Toolkit JS library available here: https://github.com/maciej-gurban/responsive-bootstrap-toolkit
Responsive Bootstrap Toolkit provides an easy way of breakpoint
detection in JavaScript, detecting changes in currently active
breakpoint, as well as executing any breakpoint-specific JavaScript
code.
The SASS module enables quick and simple styling for elements needing
different property values for each screen resolution.
Then you can do things like:
(function($, document, window, viewport){
// Listen to resize event
$(window).bind('resize', function() {
// Default 300ms poll delay
viewport.changed(function() {
// Debug
console.log( 'Current breakpoint: '+ viewport.current() );
// Trigger custom event
$('body').trigger('viewportChanged', [viewport.current()]);
}, 300)
});
// Register event listener
$(document).on('viewportChanged', 'body', function(event, current) {
console.log('Current breakpoint: '+ current);
}
})(jQuery, document, window, ResponsiveBootstrapToolkit);

You could check out some of the already available responsive design HTML boilerplates like Twitter Bootstrap or Zurb Foundation. Maybe their existing configurations satisfy your need.

I have a similar problem on two websites and i do:
JavaScript/jQuery with the window re size event and have breakpoints in JavaScript to. I then remove the item and append/prepend it where i want it to be.
On my other website i use Twitter Bootstrap which is very responsive and looks nice.
I would personally go with Twitter Bootstrap as its a nice grid system. If your site is very complex and cant be done using Twitter Bootstrap them capturing the window re size event is the best way.
$(window).resize(function() {
//Use $(window).width() and maybe some ifs/a switch to handle break points
if($(window).width()<700){
//Move it here
}
});

With CSS and JS it can be done :) You can clone the content to another section with jquery (append), then using media queries you can control what shows.
Here is what I do:
I do the appendTo:
$( $('.goto').html() ).appendTo('.mobile')
Here's an example I did:
http://jsfiddle.net/Riskbreaker/vkfWd/
This might not be what you are looking for (since its really not moving it but cloning the content )but this is the way I do it.

Slideshow in Javascript without framework, animation?

The issue I am having is fairly complicated to explain. I have written up a javascript that displays an image slideshow, and it works fairly well, despite using up more resources than I would like
// imgArr[] is populated before
var i = 0;
var pageLoaded = 0;
window.onload = function() {pageLoaded = 1;}
function loaded(i,f) {
if (document.getElementById(i) != null) f();
else if (!pageLoaded) setTimeout('loaded(\''+i+'\','+f+')',100);
}
}
function displaySlideshow() {
document.getElementById(destinationId).innerHTML = '<div id="slideWindow"><img src="'+imgArr[i]+'" />' + '<img src="'+imgArr[i + 1]+'" /></div>';
setTimeout('displaySlideshow()',1000*3);
i++;
if (i >= imgArr.length - 1)
i = 0;
}
loaded(destinationId,displaySlideshow);
So, this script dynamically adds two images to a HTML element, and it is wrapped in a div.
The div is styled with the height and width of the image, with the overflow (the second image) hidden.
The second image is below the first, and the slideshow is meant to go from RIGHT to LEFT.
My inquiry is twofold:
1) Is there a more efficient way of doing this?
2) How would I animate the images? Would I need to put the second image on the right of the first with CSS somehow, and then set a timer to pull the images (via a style) leftward?

I really don't recommend rolling your own animation library. The Facebook Animation Library written by the wonderful Marcel Laverdet is simple to use and comes with a lot of tutorials to get what you want out of your slideshow. (Note: ignore the FBJS stuff, it's exactly the same even if you're using it on your own site.)

If you're not using a framework, I think you'll find a lot of pain ahead of you. If you still don't want to use a framework, at least find one that is liberally licensed, and take a look at the source code. Here's one, for example.
The basic theory is, yes, you set a timer that moves the image on some sort of interval, either fixed or based on some sort of mathematical equation (eg, sin, cos, etc). By setting these intervals close together, and making lots of them, you get an "animation" in javascript. Typically, you'd use some sort of absolute positioning, moving one element off the screen as the other moves on.