JQuery: Onload event on image not working - javascript

I am trying to call a function after the image loads completely in DOM.
The image structure is created dynamically on AJAX call success and the image url is also added in success using the result of API call.
Problem:
I want to call a function after the image loads completely in DOM.
To do this I have used JQuery load event.
Function which is called on load.
function carouselHeight() {
$('.home-banner-img-container').each(function() {
var $this = $(this);
var dynamicheight = $(this).parent();
var sectionInnerHeight = $this.innerHeight();
dynamicheight.css({
'height': sectionInnerHeight
});
});
}
I have tried below steps but it didn't worked
$(window).on('load', function() {
carouselHeight();
});
$(window).on('load', 'img.image-preview', function() {
carouselHeight();
});
$(document).on('load', 'img.image-preview', function() {
carouselHeight();
});
The first method $(window).on('load', function() {}) works perfectly on hard reload but on normal reload it is not able to find $('.home-banner-img-container') element which is inside of carouselHeight function.
Please help me to find a solution for this. Thank you.

I have found the solution on stack overflow where I have added the below code in ajax call complete method.
function imageLoaded() {
// function to invoke for loaded image
// decrement the counter
counter--;
if( counter === 0 ) {
// counter is 0 which means the last
// one loaded, so do something else
}
}
var images = $('img');
var counter = images.length; // initialize the counter
images.each(function() {
if( this.complete ) {
imageLoaded.call( this );
} else {
$(this).one('load', imageLoaded);
}
});

Related

Jquery Animations not waiting for callback

I have a Jquery animation that is running the code from its function before the animation is complete. the Page this code is being used at is no where near complete yet but if you want to take a look it's cottageboards.com/orderform
$('#snow').fadeIn(500, "linear", function () {
$('#largeImage').fadeOut(500, function () {
$('#largeImage').attr('src', selectedimg).load(function () {
$('#largeImage').fadeIn(1000, function () {
//Everything below here is running before the above image's fade in is complete
$('#snow').fadeOut(5000);
var selection = 'input[name="' + $(selectionage).data('type') + '_selection"]';
$($('#selected_thumb').val()).attr('src', $($('#selected_thumb').val()).data('regular'));
$(selectionage).attr('src', $(selectionage).data('selected'));
selectedid = '#' + $(selectionage).attr('id');
$('#selected_thumb').val(selectedid);
$('#selected_info').html($(selectionage).data('desc'));
$('#name').html($(selectionage).data('name'));
if ($(selectionage).data('val') === 99) {
$('#upload').show();
$('#displayinfo').hide();
} else {
$(selection).val($(selectionage).data('val'));
$('#upload').hide();
$('#displayinfo').show();
}
$('#next').prop('disabled', false);
});
});
});
});
When rewritten so the load function comes before the src change it works like a charm. Thanks for the help guys!
Working code:
$('#snow').fadeIn(500, "linear", function () {
$('#largeImage').fadeOut(500, function () {
$('#largeImage').unbind().load(function () {
$('#largeImage').fadeIn(1000, function () {
$('#snow').fadeOut(5000);
var selection = 'input[name="' + $(selectionage).data('type') + '_selection"]';
$($('#selected_thumb').val()).attr('src', $($('#selected_thumb').val()).data('regular'));
$(selectionage).attr('src', $(selectionage).data('selected'));
selectedid = '#' + $(selectionage).attr('id');
$('#selected_thumb').val(selectedid);
$('#selected_info').html($(selectionage).data('desc'));
$('#name').html($(selectionage).data('name'));
if ($(selectionage).data('val') === 99) {
$('#upload').show();
$('#displayinfo').hide();
} else {
$(selection).val($(selectionage).data('val'));
$('#upload').hide();
$('#displayinfo').show();
}
$('#next').prop('disabled', false);
});
}).attr('src', selectedimg);
});
});
You are binding the load function to largeimage every time you click. The first click the load function gets called once, the second time, it gets called twice. I suspect everything is getting messed up because you are firing multiple .fadeIns on the same object, and they are running in parallel.
Only call $('#largeImage').load(...) once, not on every click. Of course, you'll have to do something about your captured vars, but that's a different issue. Alternatively, call $('#largeImage').unbind().load(...)
If that's hard to follow, replace this line:
$('#largeImage').attr('src', selectedimg).load(function () {
with:
$('#largeImage').unbind().attr('src', selectedimg).load(function () {
I tested it by putting a break point after this line:
$('#thumbs').delegate('img','click', function() {
and calling $('#largeImage').unbind(); and everything seemed to work, so you can do it that way too.
see this fiddle for example how to use done : http://jsfiddle.net/gcnes8b2/1/
$('span').click(function() {
$('#1').fadeIn({
duration: 1000,
done:function(){
$('#2').fadeOut(1000);
// etc
}
});
});

How to pass variable asyncronously through different scripts

I can't figure out how to do it.
I have two separate scripts. The first one generates an interval (or a timeout) to run a specified function every x seconds, i.e. reload the page.
The other script contains actions for a button to control (pause/play) this interval.
The pitfall here is that both sides must be asyncronous (both run when the document is loaded).
How could I properly use the interval within the second script?
Here's the jsFiddle: http://jsfiddle.net/hm2d6d6L/4/
And here's the code for a quick view:
var interval;
// main script
(function($){
$(function(){
var reload = function() {
console.log('reloading...');
};
// Create interval here to run reload() every time
});
})(jQuery);
// Another script, available for specific users
(function($){
$(function(){
var $playerButton = $('body').find('button.player'),
$icon = $playerButton.children('i');
buttonAction = function(e){
e.preventDefault();
if ($(this).hasClass('playing')) {
// Pause/clear interval here
$(this).removeClass('playing').addClass('paused');
$icon.removeClass('glyphicon-pause').addClass('glyphicon-play');
}
else {
// Play/recreate interval here
$(this).removeClass('paused').addClass('playing');
$icon.removeClass('glyphicon-play').addClass('glyphicon-pause');
}
},
buttonInit = function() {
$playerButton.on('click', buttonAction);
};
buttonInit();
});
})(jQuery);
You could just create a simple event bus. This is pretty easy to create with jQuery, since you already have it in there:
// somewhere globally accessible (script 1 works fine)
var bus = $({});
// script 1
setInterval(function() {
reload();
bus.trigger('reload');
}, 1000);
// script 2
bus.on('reload', function() {
// there was a reload in script 1, yay!
});
I've found a solution. I'm sure it's not the best one, but it works.
As you pointed out, I eventually needed at least one global variable to act as a join between both scripts, and the use of a closure to overcome asyncronous issues. Note that I manipulate the button within reload, just to remark that sometimes it's not as easy as moving code outside in the global namespace:
Check it out here in jsFiddle: yay! this works!
And here's the code:
var intervalControl;
// main script
(function($){
$(function(){
var $playerButton = $('body').find('button.player'),
reload = function() {
console.log('reloading...');
$playerButton.css('top', parseInt($playerButton.css('top')) + 1);
};
var interval = function(callback) {
var timer,
playing = false;
this.play = function() {
if (! playing) {
timer = setInterval(callback, 2000);
playing = true;
}
};
this.pause = function() {
if (playing) {
clearInterval(timer);
playing = false;
}
};
this.play();
return this;
};
intervalControl = function() {
var timer = interval(reload);
return {
play: function() {
timer.play();
},
pause: function(){
timer.pause();
}
}
}
});
})(jQuery);
// Another script, available for specific users
(function($){
$(function(){
var $playerButton = $('body').find('button.player'),
$icon = $playerButton.children('i'),
interval;
buttonAction = function(e){
e.preventDefault();
if ($(this).hasClass('playing')) {
interval.pause();
$(this).removeClass('playing').addClass('paused');
$icon.removeClass('glyphicon-pause').addClass('glyphicon-play');
}
else {
interval.play();
$(this).removeClass('paused').addClass('playing');
$icon.removeClass('glyphicon-play').addClass('glyphicon-pause');
}
},
buttonInit = function() {
$playerButton.on('click', buttonAction);
interval = intervalControl();
};
buttonInit();
});
})(jQuery);
Any better suggestion is most welcome.

Passing functions between RequireJS files

I've got a file which needs to run on page load (randomise_colors.js), but also needs to be called by another file as part of a callback function (in infinite_scroll.js). The randomise_colors script just loops through a list of posts on the page and assigns each one a color from an array which is used on the front-end.
Infinite Scroll loads new posts in to the DOM on a button click, but because the randomise_colors.js file has already ran on page load, new content loaded is not affected by this so I need it to run again. I'm open to other suggestions if it sounds like I could be tackling the problem in a different way, I'm no JS expert.
Currently I'm getting Uncaught ReferenceError: randomise_colours is not defined referring this line of infinite_scroll.js:
randomise_colours.init();
I'm calling all files that need be loaded on document.ready in app.js
require(['base/randomise-colours', 'base/infinite-scroll'],
function(randomise_colours, infinite_scroll) {
var $ = jQuery;
$(document).ready(function() {
infinite_scroll.init();
randomise_colours.init();
});
}
);
This is infinite_scroll.js which initialises Infinite Scroll and features the callback. The callback function runs whenever new items are loaded in via AJAX using the Infinite Scroll jQuery plugin. I've put asterix around the area where I need to run the randomise_colors.init() function from randomise_colors.js.
define(['infinitescroll'], function() {
var $ = jQuery,
$loadMore = $('.load-more-posts a');
function addClasses() {
**randomise_colours.init();**
};
return {
init: function() {
if($loadMore.length >= 1) {
this.setUp();
} else {
return false;
}
},
setUp: function() {
this.initInfiniteScroll();
},
initInfiniteScroll: function() {
$('.article-listing').infinitescroll({
navSelector : '.load-more-posts',
nextSelector : '.load-more-posts a',
itemSelector : '.standard-post'
}, function(newItems) {
addClasses();
});
//Unbind the standard scroll-load function
$(window).unbind('.infscr');
//Click handler to retrieve new posts
$loadMore.on('click', function() {
$('.article-listing').infinitescroll('retrieve');
return false;
});
}
};
});
And this is my randomise_colors.js file which runs fine on load, but needs to be re-called again after new content has loaded in.
define([], function() {
var $ = jQuery,
$colouredSlide = $('.image-overlay'),
colours = ['#e4cba3', '#867d75', '#e1ecb9', '#f5f08a'],
used = [];
function pickRandomColour() {
if(colours.length == 0) {
colours.push.apply(colours, used);
used = [];
}
var selected = colours[Math.floor(Math.random() * colours.length)];
var getSelectedIndex = colours.indexOf(selected);
colours.splice(getSelectedIndex, 1);
used.push(selected);
return selected;
};
return {
init: function() {
if($colouredSlide.length >= 1) {
this.setUp();
} else {
return false;
}
},
setUp: function() {
this.randomiseColours();
},
randomiseColours: function() {
console.log('randomise');
$colouredSlide.each(function() {
var newColour = pickRandomColour();
$(this).css('background', newColour);
});
}
};
});
You would have to reference randomiseColours inside the infiniteScroll file. So you need to change your define function to the following:
define(['infinitescroll', 'randomise-colours'], function(infiniteScroll, randomise_colours)
Remember that when using require you need to reference all variables through the define function, otherwise they will not be recognised.

Load Image and Fade In, but in sequential way

I'm trying to load my images and fade in. Its working. But lets suppose that I have 4 images. Right now, my script its working by loading the last image, not the first. How can I make my js load the first image, and just start loading the second after the first has been loaded?
Here's my code:
$(function(){
$("a").click(function(){
$("#load").load('load.html', function() {
$('#load img').hide();
alert($("#load img").length);
$('#load img').each( function(){
$(this).on('load', function () {
$(this).fadeIn();
});
});
});
return false;
});
});
See http://jsfiddle.net/5uNGR/15/
Try something where you are not trying to perform a fadeIn on each image as they load, but test the ok-ness of the next image in your animation queue each time ANY load event happens, then on the animation callback, see if the next one is ready. Here is a script that should work.
BTW, see http://www.sajithmr.me/javascript-check-an-image-is-loaded-or-not for more on image readiness testing.
$(function () {
// util fn to test if image loaded properly
var isImgLoadOk = function (img) {
if (!img.complete) { return false; }
if (typeof img.naturalWidth != "undefined" && img.naturalWidth == 0) {
return false;
}
return true;
};
$("a").on('click', function () {
$("#load").load('load.html', function () {
var imgs = $('#load img').hide(), //create image array and hide (chaining)
animIndex = 0, //position in the animation queue
isFading = false; //track state of whether an animation is in prog
// this is a load handler AND is called in the fadeIn callback if
// not at last image in the collection
var fadeNextImg = function () {
// make sure a load event didn't happen in the middle of an animation
if (isFading) return;
// last image in animation queue?
var isLast = animIndex == imgs.length - 1;
// get the raw image out of the collection and test if it is loaded happily
var targetImage = imgs[animIndex];
if (isImgLoadOk(targetImage)) {
// jQuery-up the htmlImage
targetImage = $(targetImage);
// increment the queue
animIndex++;
// set animation state - this will ignore load events
isFading = true;
// fade in the img
targetImage.fadeIn('slow', function () {
isFading = false;
// test to see if next image is ready to load by
// recursively calling the parent fn
if (!isLast) fadeNextImg();
});
}
};
imgs.on('load', fadeNextImg);
});
return false;
});
});
Ron's solution is a little over-engineered IMO. If your intention is indeed to load all of the images before the animation starts, then you could do something similar to the following:
$(function(){
$("a").click(function(){
$("#load").load('load.html', function() {
$('#load img').hide(); // I would recommend using css to hide the image instead
alert($("#load img").length);
$("#load img").each(function(i, image) {
setTimeout(function() { // For each image, set increasingly large timeout before fadeIn
$(this).fadeIn();
}, 2000 * i);
});
});
return false;
});
});

jQuery function attr() doesn't always update img src attribute

Context: On my product website I have a link for a Java webstart application (in several locations).
My goal: prevent users from double-clicking, i. e. only "fire" on first click, wait 3 secs before enabling the link again. On clicking, change the link image to something that signifies that the application is launching.
My solution works, except the image doesn't update reliably after clicking. The commented out debug output gives me the right content and the mouseover callbacks work correctly, too.
See it running here: http://www.auctober.de/beta/ (click the Button "jetzt starten").
BTW: if anybody has a better way of calling a function with a delay than that dummy-animate, let me know.
JavaScript:
<script type="text/javascript">
<!--
allowClick = true;
linkElements = "a[href='http://www.auctober.de/beta/?startjnlp=true&rand=1249026819']";
$(document).ready(function() {
$('#jnlpLink').mouseover(function() {
if ( allowClick ) {
setImage('images/jetzt_starten2.gif');
}
});
$('#jnlpLink').mouseout(function() {
if ( allowClick ) {
setImage('images/jetzt_starten.gif');
}
});
$(linkElements).click(function(evt) {
if ( ! allowClick ) {
evt.preventDefault();
}
else {
setAllowClick(false);
var altContent = $('#jnlpLink').attr('altContent');
var oldContent = $('#launchImg').attr('src');
setImage(altContent);
$(this).animate({opacity: 1.0}, 3000, "", function() {
setAllowClick(true);
setImage(oldContent);
});
}
});
});
function setAllowClick(flag) {
allowClick = flag;
}
function setImage(imgSrc) {
//$('#debug').html("img:"+imgSrc);
$('#launchImg').attr('src', imgSrc);
}
//-->
</script>
A delay can be achieved with the setTimeout function
setTimeout(function() { alert('something')}, 3000);//3 secs
And for your src problem, try:
$('#launchImg')[0].src = imgSrc;
Check out the BlockUI plug-in. Sounds like it could be what you're looking for.
You'll find a nice demo here.
...or just use:
$(this).animate({opacity: '1'}, 1000);
wherever you want in your code, where $(this) is something that is already at opacity=1...which means everything seemingly pauses for one second. I use this all the time.
Add this variable at the top of your script:
var timer;
Implement this function:
function setFlagAndImage(flag) {
setAllowClick(flag);
setImage();
}
And then replace the dummy animation with:
timer = window.setTimeout(function() { setFlagAndImage(true); }, 3000);
If something else then happens and you want to stop the timer, you can just call:
window.clearTimeout(timer);

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