Develop Reference

onload triggering too early for ajax content in IE

I have a page where the images are supplied dynamically and are scaled with javascript to fit within the appropriate dimensions. This was initially being done with an onload attribute in the img tag, but then I noticed that in IE, the height being returned for the image was much less in some cases than the actual height, which ended up distorting the image. I solved this by finding and resizing all the images after $(window).load() was done, which worked fine for the initial page load, but I also have the page set up to add more content with an ajax call. For the ajax content, I tried some code I found on here that improved the problem, but didn't completely solve it. Here is an example of one of my image tags
<img id="img<?php echo $prodModObj->rolloverID; ?>" class="mbImg unsized" src="<?php echo $prodModObj->img; ?>" alt="<?php echo $prodModObj->name; ?>" onerror="swapImage(<?php echo $prodModObj->rolloverID; ?>)" />
The swapImage function just swaps out the image with a placeholder if there is an error while loading. Here is my JS
function swapImage(thisImgID) {
var imgID = 'img#img' + thisImgID;
$(imgID).attr('src', '/images/NoImageAvail.jpg');
}
function checkImage(thisImgID, fitDimension, spaceDimension) {
var imgID = 'img#img' + thisImgID;
var imgHeight = $(imgID).height();
var imgWidth = $(imgID).width();
var displayHeight, displayWidth, newMargin;
if (imgHeight > imgWidth) {
displayHeight = fitDimension;
displayWidth = imgWidth*(displayHeight/imgHeight);
} else if (imgHeight < imgWidth) {
displayWidth = fitDimension;
displayHeight = imgHeight*(displayWidth/imgWidth);
} else {
displayWidth = fitDimension;
displayHeight = fitDimension;
}
$(imgID).css('height', displayHeight);
$(imgID).css('width', displayWidth);
newMargin = ((spaceDimension - displayHeight)/2);
$(imgID).css('margin-top', newMargin);
$(imgID).removeClass('mbImg unsized').addClass('mbImg sized');
}
And then on the page I have
$(window).load(function(){
// Resize product images
$('.mbImg.unsized').each( function() {
var rolloverID = $(this).attr('id').substr(3);
checkImage(rolloverID,250,270);
});
});
And then in the success portion of the ajax call, I have
$('.mbImg.unsized').each( function() {
var rolloverID = $(this).attr('id').substr(3);
if (this.complete) {
checkImage(rolloverID,250,270);
} else {
$(this).on('load', function(){
checkImage(rolloverID,250,270);
});
}
});
Images that have been cached by the browser work fine, and the images in the initial page load work fine, but about 1 in 5 of new ajax images come out distorted. Is there another method I can use to size all the ajax images correctly in IE?
Thanks for your help,

Maybe come at it another way?
I've tried to move away from html4 style tag syntax, to using simple html5 tags and a combination of JavaScript and CSS to control the "view".
Check out this fiddle:
http://jsfiddle.net/zacwolf/s1haq3mz/
A question becomes how you want your images to flow, as using this approach all of the images are technically the same size (as demonstrated by the border). Also note that the .src for the second image I tweeked the url a bit so that it was a 404 for the image file, which triggered the one error image instead.
<img id="one" class="myclass" />
<img id="two" class="myclass" />
<style>
.myclass{
height:270px;
width:250px;
background-position:center,center;
background-repeat:no-repeat;
background-size:contain;
}
</style>
<script>
var one = new Image();
one.onerror=
function(){
this.src='http://leomarketingep.com/wp-content/uploads/Sign-Error-icon.png'
}
one.onload=
function(){
$('#one').css('background-image','url('+one.src+')')
}
one.src='https://cjjulian.files.wordpress.com/2009/04/blah_blah_blah-703369.jpg';
var two = new Image();
two.onerror=
function(){
this.src='http://leomarketingep.com/wp-content/uploads/Sign-Error-icon.png';
}
two.onload=
function(){
$('#two').css('background-image','url('+two.src+')')
}
two.src='https://cjjulian.files.wordpress.com/2019/04/blah_blah_blah-703369.jpg';
</script>
If you have a lot of images, you can populate an array of Image objects, for better referencing, etc.

How to contain a mouseover image link without the new image moving objects above it?

What I would like is when the new image loads on mouseover, it does not move any objects above it. I've tried containing it in a div, but for some reason I cannot get this to work. Any help or ideas on what I could do?
Here is a page with what it does now:
click
And here is my code:
<head>
<script type="text/javascript">
function rollover() {
if (!document.getElementById) return
var imgOrSrc;
var imgPreload = new Array();
var images = document.getElementsByTagName('img');
for (var i = 0; i < images.length; i++) {
if (images[i].getAttribute('rsrc')) {
imgPreload[i] = new Image();
imgPreload[i].src = images[i].getAttribute('rsrc');
images[i].onmouseover = function() {
imgOrSrc = this.getAttribute('src');
this.setAttribute('src',this.getAttribute('rsrc'))
}
images[i].onmouseout = function() {
this.setAttribute('src',imgOrSrc)
}
}
}
}
</script>
</head>
<body onLoad="rollover()">
<div id="landimage">
<img src="/images/braeden.png" rsrc="/images/braeden2.png" border="0">
</div>
</body>

This is simply because the images are not of the same dimensions. The easiest method would be to increase the canvas size of /images/braeden.png and adding a whitespace to the top of it so it becomes exactly the same height as /images/braeden2.png
If you do not want to to that, then you have to add padding-top to the containing div, when the smaller image is being displayed, to cater for the height difference.

using onmouseover as

I have a continuous loop of alternating images that I would like to be able to interrupt and have display a new picture that corresponds with the current displayed picture using an onmouseover affect for as long as the mouse is on the image.
As an example to better describe my problem, I would like to have a bunch of images alternating on the screen every five seconds (which I can already do). Then when the mouseover event happens, have the images stop alternating and have a new image displayed that corresponds with the image that was just displayed (it will be another image that describes the image that was just being displayed). I also want the images to stop alternating while the mouse is over the images.
So far I can get the first image to display its corresponding image, but I can't seem to get the rest to work. Also I can't get the alternating images to stop while the mouse is still on the image.
Here's what I have so far:
<body>
<img src="image1.jpeg" alt="Image1" width="344" height="311" id="rotator" onmouseover="this.src='imageText1.jpeg'" onmouseout="this.src='image1.jpeg'">
<script type="text/javascript">
(function() {
var rotator = document.getElementById("rotator");
var imageDir = '';
var delayInSeconds = 5;
var images = ["image2.png", "image3.gif", "image4.png", "image5.jpeg","image6.gif", "image7.jpeg", "image1.jpeg"];
var num = 0;
if (rotator.onmouseover == )
var changeImage = function() {
var len = images.length;
rotator.src = imageDir + images[num++];
if (num == len) {
num = 0;
}
};
setInterval(changeImage, delayInSeconds * 1000);
})();
</script>

if (rotator.onmouseover == )
{
}
we must check something in if conditon.
empty condition is a problem.please check it.

Using javascript to derive height of image when only resized width is explicitly given in html

Forgive my ignorance of javascript, but I'm trying to create a simple image hover that enlarges the image when you hover your mouse over it. (And no, I don't want to use JQuery. I want to learn this directly in javascript!) My problem is that only the width is specified in the html. The height is omitted so that the image displays proportionally on the page. When I hover over the image with my mouse, the javascript works fine in IE, but in FF, Chrome, Safari, etc. img.offsetHeight gets assigned 0 rather than a proportion of img.offsetWidth.
<script type="text/javascript">
var img=document.getElementById('imageid');
var thiswidth=img.offsetWidth;
var thisheight=img.offsetHeight;
var ratio=thisheight/thiswidth;
var bigwidth=600;
var bigheight=bigwidth*ratio;
function bigImg(x) {
x.style.width=bigwidth;
x.style.height=bigheight;
}
function normalImg(x) {
x.style.width=thiswidth;
x.style.height=thisheight;
}
</script>
<img id="imageid" onmouseover="bigImg(this)" onmouseout="normalImg(this)" src="myimage.jpg" alt="image" width="200" >
As you can see from the img tag, height is inferred proportional to width by not being specified. Can someone tell me how I can use javascript to derive thisheight from thiswidth?

this will work for you in all ie FF, Chrome, Safari, etc
<html>
<body>
<img id="imageid" onmouseover="bigImg(this)" onmouseout="normalImg(this)" src="C810623C.gif" alt="image" width="200" >
<script type="text/javascript">
var img = document.getElementById('imageid');
var normsizeimg = img.style.width;
var bigwidth = 600;
function bigImg(x)
{ x.style.width = bigwidth; }
function normalImg(x) { x.style.width = normsizeimg; }
</script>
</body>
</html>

this is why it's easier to do such things with jquery, some browsers keep dimension values in offsetWidth others don't;
here's a tip of how you can get across this problem
var thiswidth=img.offsetWidth;
var thisheight=img.offsetHeight;
//it's non IE browser
if(XMLHttpRequest){
var thisheight=img.clientHeight;
var thiswidth=img.clientWidth;
}

This works fine for me on Firefox (I don't have access to other browsers right now, sorry):
<img id="imageid" src="myimage.jpg" alt="image" width="200" >
<script type="text/javascript">
var img = document.getElementById('imageid');
img.onload = function(){
var thiswidth = img.offsetWidth;
var thisheight = img.offsetHeight;
var ratio = thisheight/thiswidth;
var bigwidth = 600;
var bigheight = bigwidth*ratio;
img.onmouseover = function bigImg() {
img.style.width = bigwidth;
img.style.height = bigheight;
}
img.onmouseout = function normalImg(x) {
img.style.width = thiswidth;
img.style.height = thisheight;
}
};
</script>
The main differences between this code and yours is that:
I'm only accessing the element after it is declared
I'm only accessing its properties after the image loads
I'm also only adding the onmouseover and onmouseout attributes later because it makes the HTML look cleaner, but that's optional.
Update: actually, adding the event handlers later isn't optional, because they use the calculated bigwidth and bigheight, which are only available after the image loads.

Change pre-defined body background image

I found this script to change the body's background image when you click a link. It works, great except the only problem is is that I cannot have a pre-defined bg image in the css or else it won't change.
So I remove the css for the background image and it switches the images fine, but I want an image to be default to start with.
Script:
<script language="JavaScript">
<!--
var backImage = new Array(); // don't change this
backImage[0] = "images/bg0.png";
backImage[1] = "images/bg1.png";
backImage[2] = "images/bg2.png";
backImage[3] = "images/bg3.png";
backImage[4] = "images/bg4.png";
backImage[5] = "images/bg5.png";
function changeBGImage(whichImage){
if (document.body){
document.body.background = backImage[whichImage];
}
}
//-->
</script>
Link:
Change2
And, for example, I want bg0.png to be the background by default when the page loads.
It would also be great if it was possible to fade between the bg images.
Thanks in advance.

Keep the background in the CSS, and use this code instead
var backImage = [
"images/bg0.png",
"images/bg1.png",
"images/bg2.png",
"images/bg3.png",
"images/bg4.png",
"images/bg5.png"
];
function changeBGImage(whichImage) {
if (document.body){
document.body.style.backgroundImage = 'url('+backImage[whichImage]+')';
}
}

To change the background if you have one defined in the css you need to alter: document.body.style.backgroundImage attribute