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"touchend" event partly not working on iphone mobile browser

On the mobile version of the website I have made, I use a javascript file to handle the tap of a user to open up the side display.
What I wanted to do was if a user presses the side display it should expand, if the touch area is not the side display shrink back to the original state.
It is currently working on samsung browsers, I have also tried on iphones using a chrome and safari browser and it expands when pressed on the side display but only closes when I press the button located on the lower right hand corner. The areas excluding the side navigation and the background do not initiate the div to return to original state.
Here is my javascript code for handling touch events:
document.getElementById('side_box').addEventListener('touchend', function(event){
var touchobj = event.changedTouches[0] // reference first touch point for this event
const vals = document.getElementById('val-display');
const lst_elem = document.getElementsByClassName('list-element');
const arrow = document.getElementById('arrow');
if(screen && screen.width < 480) {
if (event.target === this || event.target === arrow) {
this.style.opacity = "0.7";
this.style.width = "200px";
vals.style.opacity = "0";
arrow.style.display = "none";
for (let i = 0; i < lst_elem.length; i++) {
lst_elem[i].style.visibility = "visible";
}
} else {
this.style.opacity = "0.3";
this.style.width = "50px";
vals.style.opacity = "1";
arrow.style.display = "block";
for (let i = 0; i < lst_elem.length; i++) {
lst_elem[i].style.visibility = "hidden";
}
}
}
event.preventDefault();
}, false);
The if statement is currently working perfect but there is a problem in the else not initiating when pressed anywhere else except the side display.
You can also check the problem by going on andy.serra.us on your mobile.
Thanks for the help in advance.

Javascript hiding and showing dynamic content of a div

Currently I hide and show the content of a div like this:
var header = null;
var content = null;
var mainHolder = null;
var expandCollapseBtn = null;
var heightValue = 0;
header = document.getElementById("header");
content = document.getElementById("content");
mainHolder = document.getElementById("mainHolder");
expandCollapseBtn = header.getElementsByTagName('img')[0];
heightValue = mainHolder.offsetHeight;
header.addEventListener('click', handleClick, false);
mainHolder.addEventListener('webkitTransitionEnd',transitionEndHandler,false);
function handleClick() {
if(expandCollapseBtn.src.search('collapse') !=-1)
{
mainHolder.style.height = "26px";
content.style.display = "none";
}
else
{
mainHolder.style.height = heightValue + "px";
}
}
function transitionEndHandler() {
if(expandCollapseBtn.src.search('collapse') !=-1)
{
expandCollapseBtn.src = "expand1.png";
}
else{
expandCollapseBtn.src = "collapse1.png";
content.style.display = "block";
}
}
This is fine if the content is static, but I'm trying to populate my div dynamically like so.
This is called from an iphone application and populates the div with a string.
var method;
function myFunc(str)
{
method = str;
alert(method);
document.getElementById('method').innerHTML = method;
}
I store the string globally in the variable method. The problem I am having is now when I try expand the div I have just collapsed there is nothing there. Is there some way that I could use the information stored in var to repopulate the div before expanding it again? I've tried inserting it like I do in the function but it doesn't work.
Does anyone have any ideas?
to replicate:
Here is the jsfiddle. jsfiddle.net/6a9B3 If you type in text between
here it will work fine. I'm not sure
how I can call myfunc with a string only once in this jsfiddle, but if
you can work out how to do that you will see it loads ok the first
time, but when you collapse the section and attempt to re open it, it
wont work.
If the only way to fix this is using jquery I dont mind going down that route.

is it working in other browsers?
can you jsfiddle.net for present functionality because it is hard to understand context of problem in such code-shoot...
there are tonns of suggestions :) but I have strong feeling that
document.getElementById('method')
returns wrong element or this element not placed inside mainHolder
update: after review sample in jsfiddle
feeling about wrong element was correct :) change 'method' to 'info'
document.getElementById('method') -> document.getElementById('info')

I think you want to use document.getElementById('content') instead of document.getElementById('method') in myFunc.

I really see nothing wrong with this code. However, a guess you could explore is altering the line
content.style.display = "none";
It might be the case that whatever is displaying your html ( a webview or the browser itself) might be wiping the content of the elemtns, as the display is set to none

Menu that fit to the buttom/top of the screen

I saw a cool style/js function (I can tell what it is) that implemented on a side menu.
You know the situation when you have a long center page and one of / both of you sides ends and that leave a blank space? Well this site implemented this thing that just when the user scrool to the place where the side menu end - the menu get absolute postion and doesnt move.
How can I do this?
If you want to see an example you can look here (just scroll and look on the sides)

I believe you can achieve similar effect using this: http://www.wduffy.co.uk/blog/keep-element-in-view-while-scrolling-using-jquery/comment-page-1/ (just making it move with 0 as speed parameter instead of slow, as in the example) and adding conditions about whether the current position fits within the box it is displayed (you can take height of the box - menu being moved on page or box that contains the menu - by using .height() jQuery function).
EDIT:
The page you referenced uses the following JavaScript code to support what you try to accomplish:
<script type="text/javascript">
$(function(){
var seoHeight = $$('dvIndexSeoMaster').height();
seoHeight = (seoHeight > 0) ? seoHeight : 0;
var documentHeight = $(document.body).height() - 120 - seoHeight;
var fixedMode = false;
var hasFixedClass = false;
var leftColElm = $sc('dvFixed');
var leftColPos = leftColElm.offset().top;
var leftColHeight = leftColElm.height();
var rightColElm = $$('dvIndexMasterRightCol');
var rightColPos = rightColElm.offset().top;
var rightColHeight = rightColElm.height();
function scrollElm(elmPos,elmHeight,objElm, cssClass){
var fixedMode = false;
var hasFixedClass = false;
var windowTop = $(window).scrollTop();
(windowTop >= elmPos && (windowTop + elmHeight) < documentHeight) ? fixedMode = true : fixedMode = false;
if( fixedMode){
$(objElm).addClass(cssClass);
hasFixedClass = true;
}else if( (fixedMode == false)){
$(objElm).removeClass(cssClass);
hasFixedClass = false;
}
};
$(window).scroll(function(){
scrollElm(leftColPos,leftColHeight,leftColElm,'make-fixed');
scrollElm(rightColPos,rightColHeight,rightColElm, 'make-fixed');
});
});
</script>
And the make-fixed CSS class has the following definition:
.make-fixed {
position: fixed;
top: 0;
z-index: 200;
}

You can make an element stay in the same place, even as the user scrolls, with the CSS position:fixed property: http://www.w3.org/TR/CSS2/visuren.html#fixed-positioning

How to improve image cross-fade performance?

I want to be able to do a cross fade transition on large images whose width is set to 100% of the screen. I have a working example of what I want to accomplish. However, when I test it out on various browsers and various computers I don't get a buttery-smooth transition everywhere.
See demo on jsFiddle: http://jsfiddle.net/vrD2C/
See on Amazon S3: http://imagefader.s3.amazonaws.com/index.htm
I want to know how to improve the performance. Here's the function that actually does the image swap:
function swapImage(oldImg, newImg) {
newImg.css({
"display": "block",
"z-index": 2,
"opacity": 0
})
.removeClass("shadow")
.animate({ "opacity": 1 }, 500, function () {
if (oldImg) {
oldImg.hide();
}
newImg.addClass("shadow").css("z-index", 1);
});
}
Is using jQuery animate() to change the opacity a bad way to go?

You might want to look into CSS3 Transitions, as the browser might be able to optimize that better than Javascript directly setting the attributes in a loop. This seems to be a pretty good start for it:
http://robertnyman.com/2010/04/27/using-css3-transitions-to-create-rich-effects/

I'm not sure if this will help optimize your performance as I am currently using IE9 on an amped up machine and even if I put the browser into IE7 or 8 document mode, the JavaScript doesn't falter with your current code. However, you might consider making the following optimizations to the code.
Unclutter the contents of the main photo stage by placing all your photos in a hidden container you could give an id of "queue" or something similar, making the DOM do the work of storing and ordering the images you are not currently displaying for you. This will also leave the browser only working with two visible images at any given time, giving it less to consider as far as stacking context, positioning, and so on.
Rewrite the code to use an event trigger and bind the fade-in handling to the event, calling the first image in the queue's event once the current transition is complete. I find this method is more well-behaved for cycling animation than some timeout-managed scripts. An example of how to do this follows:
// Bind a custom event to each image called "transition"
$("#queue img").bind("transition", function() {
$(this)
// Hide the image
.hide()
// Move it to the visible stage
.appendTo("#photos")
// Delay the upcoming animation by the desired value
.delay(2500)
// Slowly fade the image in
.fadeIn("slow", function() {
// Animation callback
$(this)
// Add a shadow class to this image
.addClass("shadow")
// Select the replaced image
.siblings("img")
// Remove its shadow class
.removeClass("shadow")
// Move it to the back of the image queue container
.appendTo("#queue");
// Trigger the transition event on the next image in the queue
$("#queue img:first").trigger("transition");
});
}).first().addClass("shadow").trigger("transition"); // Fire the initial event
Try this working demo in your problem browsers and let me know if the performance is still poor.

I had the same problem too. I just preloaded my images and the transitions became smooth again.

The point is that IE is not W3C compliant, but +1 with ctcherry as using css is the most efficient way for smooth transitions.
Then there are the javascript coded solutions, either using js straight (but need some efforts are needed to comply with W3C Vs browsers), or using libs like JQuery or Mootools.
Here is a good javascript coded example (See demo online) compliant to your needs :
var Fondu = function(classe_img){
this.classe_img = classe_img;
this.courant = 0;
this.coeff = 100;
this.collection = this.getImages();
this.collection[0].style.zIndex = 100;
this.total = this.collection.length - 1;
this.encours = false;
}
Fondu.prototype.getImages = function(){
var tmp = [];
if(document.getElementsByClassName){
tmp = document.getElementsByClassName(this.classe_img);
}
else{
var i=0;
while(document.getElementsByTagName('*')[i]){
if(document.getElementsByTagName('*')[i].className.indexOf(this.classe_img) > -1){
tmp.push(document.getElementsByTagName('*')[i]);
}
i++;
}
}
var j=tmp.length;
while(j--){
if(tmp[j].filters){
tmp[j].style.width = tmp[j].style.width || tmp[j].offsetWidth+'px';
tmp[j].style.filter = 'alpha(opacity=100)';
tmp[j].opaque = tmp[j].filters[0];
this.coeff = 1;
}
else{
tmp[j].opaque = tmp[j].style;
}
}
return tmp;
}
Fondu.prototype.change = function(sens){
if(this.encours){
return false;
}
var prevObj = this.collection[this.courant];
this.encours = true;
if(sens){
this.courant++;
if(this.courant>this.total){
this.courant = 0;
}
}
else{
this.courant--;
if(this.courant<0){
this.courant = this.total;
}
}
var nextObj = this.collection[this.courant];
nextObj.style.zIndex = 50;
var tmpOp = 100;
var that = this;
var timer = setInterval(function(){
if(tmpOp<0){
clearInterval(timer);
timer = null;
prevObj.opaque.opacity = 0;
nextObj.style.zIndex = 100;
prevObj.style.zIndex = 0;
prevObj.opaque.opacity = 100 / that.coeff;
that.encours = false;
}
else{
prevObj.opaque.opacity = tmpOp / that.coeff;
tmpOp -= 5;
}
}, 25);
}

Dashcode webapp flickers upon transition, only in iPhone Safari

I created a simple RSS web app using the template in Dashcode. Problem is, when choosing items in the list from the feed the transition flickers (even with the default settings). I am guessing its because of the images in the posts.
I tried disabling the transitions completely but even then I get a flickering when returning to the list. This problem does not appear to affect safari on OSX only on the iphone.
Here is the code that I think is responsible:
var topStories = parseInt(attributes.topStories, 30);
function load()
{
dashcode.setupParts();
// set today's date
var todaysDate = document.getElementById("todaysDate");
todaysDate.innerText = createDateStr(new Date()).toUpperCase();
setupFilters("headlineList");
// This message checks for common errors with the RSS feed or setup.
// The handler will hide the split view and display the error message.
handleCommonErrors(attributes.dataSource,
function(errorMessage) {
var stackLayout = document.getElementById("StackLayout")
if (stackLayout) {
stackLayout.style.display = 'none';
}
showError(errorMessage);
});
// get notifications from the stack layout when the transition ends
document.getElementById("StackLayout").object.endTransitionCallback = function(stackLayout, oldView, newView) {
// clear selection of lists when navigating to the first view
var firstView = stackLayout.getAllViews()[0];
if (newView == firstView) {
document.getElementById("headlineList").object.clearSelection(true);
}
}
}
function articleClicked(event)
{
document.getElementById("StackLayout").object.setCurrentView("articlePage", false, true);
}
function backToArticlesClicked(event)
{
document.getElementById("StackLayout").object.setCurrentView("frontPage", true);
}
function readMoreClicked(event)
{
var headlineList = dashcode.getDataSource('headlineList');
var secondHeadlines = dashcode.getDataSource("secondHeadlines");
var selectedItem = null;
if (headlineList.hasSelection()) {
selectedItem = headlineList.selectedObjects()[0];
} else if (secondHeadlines.hasSelection()) {
selectedItem = secondHeadlines.selectedObjects()[0];
}
if (selectedItem) {
var link = selectedItem.valueForKeyPath('link');
// If the link is an object, not a string, then this may be an ATOM feed, grab the actual
// href from the href attr
if (typeof(link) == 'object') {
link = selectedItem.valueForKeyPath('link.$href');
// If the link is an array (there is more then one link), just grab the first one
if (DC.typeOf(link) == 'array') {
link = link[0];
}
}
window.location = link;
}
}
var headlineListDataSource = {
// The List calls this method once for every row.
prepareRow: function(rowElement, rowIndex, templateElements) {
if (rowIndex >= topStories) {
templateElements['headlineDescription'].style.display = 'none';
templateElements['headlineTitle'].style.fontSize = '15px';
}
}
};

The following CSS rule fixed all of my "-webkit-transition" animation flickering issues on the iPad:
body {-webkit-transform:translate3d(0,0,0);}

I am not sure how well that applies to your problem but in general you should set the backface visibility to hidden if not needed. That will most likely kill all flickering on a page.
-webkit-backface-visibility: hidden;