The code I’m working with is too long to post, so I’ve made a fiddle here: http://jsfiddle.net/Emily92/5b72k225/
This code takes a random image and cuts it up into a number of pieces depending on the class that is applied in the div which contains the image.
When the page loads, a random image is selected from the array and the class is applied to it, what I’m trying to do is create a separate div, which when clicked on will reload the div containing the image. The result I’m looking for is for the image to be replaced by a new random image with the class applied to it.
Right now, the only way I can make a new image appear in the div is to reload the entire page, ideally this would be achieved by just having the div reload instead of all the other page elements reloading too.
I haven’t been able to do this so far but have received some help on here on how to reload an image and class on click of a div, lines 980-1018 of the Javascript code in the jsfiddle is the current attempt at achieving this, but solving this problem seems much more complicated as the image is being manipulated by the Javascript code, so perhaps this needs to also be reloaded at the same time as the new randomised image is selected?
This is the current attempt at solving this problem:
$(function() {
var imageArray = [
'http://www.webdesignhot.com/wp-content/uploads/2009/10/CatsVectorImage.jpg',
'http://www.costume-works.com/images/halloween_cat_in_witch_hat.jpg',
'http://onthewight.com/wp-content/2013/04/sooty-ryde.jpg'];
reloadImages(imageArray);
$('#reload').on('click',function(){
$( "#masterdiv img[id^='div']" ).each(function(index){
$(this).removeClass("jqPuzzle jqp-r"+(index+3)+"-c"+(index+3)+"-SCN");
$(this).fadeOut( "slow", function() {
if(index==0) {
reloadImages(imageArray);
}
$(this).addClass("jqPuzzle jqp-r"+(index+3)+"-c"+(index+3)+"-SCN");
$(this).fadeIn();
});
});
});
});
function shuffleArray(array) {
for (var i = array.length - 1; i > 0; i--) {
var j = Math.floor(Math.random() * (i + 1));
var temp = array[i];
array[i] = array[j];
array[j] = temp;
}
return array;
}
function reloadImages(array){
shuffleArray(array);
for(var i=0;i<3;i++){
// places the first image into all divs
document.getElementById('div'+(i+1)+'id').src=array[0];
}
}
I’ve written more details on the issue in the html section of the jsfiddle. I'd really appreciate any advice in solving this and thank you for any help in advance!
The plugin reads the images' src before page load, takes them and then generates the puzzle. As such, you can not just update the images as they're not there anymore. So you'd have to clear the divs under each difficulty classes (easyDiv,mediumDiv,hardDiv), append a new <img> under each div then calls / reload the plugin. Updated code in : http://jsfiddle.net/5b72k225/6/
Changes I've made:
Separate old reloadImages into initImages and reloadImages. initImages is called in the beginning, while reloadImages is called when reloading.
Created new function makePuzzle by taking out the intialization of the plugin from $(document).ready() block, so makePuzzle can be called after reloading new image.
The new $(document).ready() block now initializes the images and attaches click event handler to the button. When clicked, divs are emptied, new <img>s inserted and plugin is called.
Hello Stack Overflow community, recently, I've been working on a quick image display using jQuery. It has a list of possible images that can be picked and displayed at random. The issue is, after the page has finished loading, jQuery ceases to detect image load errors for if the image is invalid.
My current method of finding and fixing errors is as follows:
$('img').error(function() {
$(this).attr('src',getImgUrl());
});
This, in normal circumstances such as the page being loaded, picks a valid image, even if multiple invalid images are specified in a row. However, after the page is finished loading, if an invalid image is picked, and fails to load, this function is not even called. Strangely enough though, if I add an onerror attribute to all images, they are always called from the onerror no matter if the page was freshly loaded or not, so why is jQuery having this issue? Any help is appreciated, thanks.
UPDATE:
It also appears this is happening to other jQuery functions as well, such as click.
UPDATE:
It would appear to be an issue with jQuery recognizing new elements on a page, such as newly created images.
UPDATE for those asking getImageUrl:
function getImgUrl()
{
var text = (Math.round(Math.random() * 3)).toString();
var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
for(var i=0; i < 4; i++ )
text += possible.charAt(Math.floor(Math.random() * possible.length));
return '/' + text;
}
All this does is pick a random URL, which matches occasionally to an image on my web-server that has many many images.
It would appear that jQuery has issues recognizing new elements on the page, so the way I fixed this was instead of deleting and adding images to the page, I just edited the existing SRC of images when doing changes, which strangely enough, the jQuery error function responds perfectly to.
Here's the refresh function I ended up coming up with for all interested:
function refreshImages()
{
var images = 10;
for(var i = 0;i < images;i++)
{
var url = getImgUrl();
$('#thumb' + i).attr('src',url);
if(i == 0)
{
$('#fullimage').attr('src',url);
$('.thumb').css('border','2px solid white');
}
}
resize();
}
Title is self-explanatory, but I'll provide a step-by-step view on the matter. Hopefully I'm not the first one to have noticed this (apparently) bug on Webkit/Chrome.
I want to reset a GIF animation. All of the examples I've seen so far either simply set the src of the image to itself or set it to an empty string followed by the original src again.
Take a look at this JSFiddle for reference. The GIF resets perfectly fine on IE, Firefox and Chrome.
The issue which I have is when the image has display:none on Google Chrome only.
Check this JSFiddle. The GIF resets fine on IE and Firefox before being displayed in the page, but Chrome simply refuses to reset its animation!
What I've tried so far:
Setting the src to itself as in Fiddle, doesn't work in Chrome.
Setting the src to an empty string and restoring it to the default, doesn't work either.
Putting an wrapper around the image, emptying the container through .html('') and putting the image back inside of it, doesn't work either.
Changing the display of the image through .show() or .fadeIn() right before setting the src doesn't work either.
The only workaround which I've found so far is keeping the image with its default display and manipulating it through .animate()ing and .css()ing the opacity, height and visibility when necessary to simulate a display:none behaviour.
The main reason (context) of this question is that I wanted to reset an ajax loader GIF right before fading it in the page.
So my question is, is there a proper way to reset a GIF image's animation (which avoids Chrome's display:none "bug") or is it actually a bug?
(ps. You may change the GIF in the fiddles for a more appropriate/longer animation gif for testing)
The most reliable way to "reset" a GIF is by appending a random query string. However this does mean that the GIF will be redownloaded every time so make sure it's a small file.
// reset a gif:
img.src = img.src.replace(/\?.*$/,"")+"?x="+Math.random();
Chrome deals with style changes differently than other browsers.
In Chrome, when you call .show() with no argument, the element is not actually shown immediately right where you call it. Instead, Chrome queues the application of the new style for execution after evaluating the current chunk of JavaScript; whereas other browsers would apply the new style change immediately. .attr(), however, does not get queued. So you are effectively trying to set the src when the element is still not visible according to Chrome, and Chrome won't do anything about it when the original src and new src are the same.
Instead, what you need to do is to make sure jQuery sets the src after display:block is applied. You can make use of setTimeout to achieve this effect:
var src = 'http://i.imgur.com/JfkmXjG.gif';
$(document).ready(function(){
var $img = $('img');
$('#target').toggle(
function(){
var timeout = 0; // no delay
$img.show();
setTimeout(function() {
$img.attr('src', src);
}, timeout);
},
function(){
$img.hide();
}
);
});
This ensures that src is set after display:block has been applied to the element.
The reason this works is because setTimeout queues the function for execution later (however long later is), so the function is no longer considered to be part of the current "chunk" of JavaScript, and it provides a gap for Chrome to render and apply the display:block first, thus making the element visible before its src attribute is set.
Demo: http://jsfiddle.net/F8Q44/19/
Thanks to shoky in #jquery of freenode IRC for providing a simpler answer.
Alternatively, you can force a redraw to flush the batched style changes. This can be done, for example, by accessing the element's offsetHeight property:
$('img').show().each(function() {
this.offsetHeight;
}).prop('src', 'image src');
Demo: http://jsfiddle.net/F8Q44/266/
Just because I still need this every now and then I figured the pure JS function I use might be helpful for someone else. This is a pure JS way of restarting an animated gif, without reloading it. You can call this from a link and/or document load event.
<img id="img3" src="../_Images/animated.gif">
<a onClick="resetGif('img3')">reset gif3</a>
<script type="text/javascript">
// reset an animated gif to start at first image without reloading it from server.
// Note: if you have the same image on the page more than ones, they all reset.
function resetGif(id) {
var img = document.getElementById(id);
var imageUrl = img.src;
img.src = "";
img.src = imageUrl;
};
</script>
On some browsers you only need to reset the img.src to itself and it works fine. On IE you need to clear it before resetting it. This resetGif() picks the image name from the image id. This is handy in case you ever change the actual image link for a given id because you do not have to remember to change the resetGiF() calls.
--Nico
This solution preloads the gif and takes it out of the dom and then back in the src (thus avoiding another download)
I just tested it using jquery to remove the attribute and it works fine.
Example:
<html>
<head>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js" type="text/javascript"></script>
<script>
$(function() {
$('.reset').click(resetGif);
function resetGif()
{
$('.img1').removeAttr('src', '');
}
});
</script>
</head>
<body>
<img class="img1" src="1.gif" />
reset gif
</body>
</html>
This seemed to work for me in Chrome, it runs each time just before I fade in the image and clears then refills the src and my animation now starts from the beginning every time.
var imgsrc = $('#my_image').attr('src');
$('#my_image').attr('src', '');
$('#my_image').attr('src', imgsrc);
I've a button with the an animated no-loop image in it. I just reload the image with some jquery and this seems to be working for me.
var asdf = $(".settings-button img").attr("src");
$(".settings-button img").attr("src", "").attr("src", asdf);
here's my hack for background images:
$(document).on('mouseenter', '.logo', function() {
window.logo = (window.logocount || 0) + 1;
var img = new Image();
var url = "/img/mylogimagename.gif?v=" + window.logocount;
var that = this;
$(img).load(function(){
$(that ).css('background-image','url(' + url + ')');
});
img.src = url;
});
I experienced problems with all of the above solutions. What finally worked was replacing the src temporarily with a transparent 1px gif:
var transparent1PxGif = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7';
var reloadGif = function(img) {
var src = img.src;
img.src = transparent1PxGif;
img.offsetHeight; // triggers browser redraw
img.src = src;
};
It's been several years and I've decided to revisit this since we have a number of new options at our disposal.
The issue with my previous answer is that it forces a re-download of the GIF every single time you want to re-start it. While that's fine for small files, it's still an overhead that's best avoided if possible.
With that in mind, I've got a new solution that uses AJAX to download the GIF once, and then converts it into a data URL (via a FileReader) and uses that as the source with a random query string attached.
This way, the browser only ever downloads the image once, and can even cache it properly, and the "reset" pulls from that pre-downloaded resource.
The only catch, of course, is that you have to make sure it's properly loaded before you can use it.
Demo: http://adamhaskell.net/misc/numbers/numbers.html
Relevant code:
var url = "something.gif"; // fallback until the FileReader is done
function setup() {
var xhr = new XMLHttpRequest();
xhr.open("GET",url,true);
xhr.responseType = "blob";
xhr.onreadystatechange = function() {
if( this.readyState == 4) {
var fr = new FileReader();
fr.onload = function() {
url = this.result; // overwrite URL with the data one
};
fr.readAsDataURL(this.response);
}
};
xhr.send();
}
function getGIF() {
return url+"?x="+Math.random();
}
Reset gif animation
When the browser render img, the source specified in src attribute is cached into memory for future reuse. This allows to increase the speed of page loading/reloading, as well as reduce the load on the network. And this behavior suits mostly everyone, because in reality, this is the most optimal and demanded option.
However, as always, there are exceptions. I came up with a dataUrl-based animation update option that solves several problems.
Issues solved:
Need to display gif images with animation without a loop (loop = 1), which may have the same src. But when one such picture appears, it is necessary that it play the animation without changing the animation of other pictures with the same src. The same picture should be loaded from server only once. Stackoverflow
Reset gif animation.
Start animation on hover
Reset src attribute
If we use a solution that clears the src attribute of an image, then all images with the same source will replay their animation. Unfortunately, I still did not fully understand why this is happening, but it interferes with correct work.
Cons
Reset animation of all images with the same src.
There are problems in mobile devices
Pros
Easy and fast
Modify url with random query
This solution consists in adding a random query parameter to the end of the src attribute, so that all images will have a different source, and therefore they will animate independently of each other. There is one big fat NO: this will lead to a constant request to the server to download the picture, and therefore they will no longer be cached. And if we need to display 100 identical pictures, then there will be 100 requests to the server. Rough and tough, but it always works.
Cons
Each picture with a unique query will be reloaded from the server.
Pros
Easy and fast
Modify dataUrl (Proposed Solution)
Data URLs, URLs prefixed with the data: scheme, allow content creators to embed small files inline in documents. They were formerly known as "data URIs" until that name was retired by the WHATWG.
MDN
The dataUrl structure from this documentation:
data:[<mediatype>][;base64],<data>
And this is how it is indicated in the specification:
dataurl := "data:" [ mediatype ] [ ";base64" ] "," data
mediatype := [ type "/" subtype ] *( ";" parameter )
data := *urlchar
parameter := attribute "=" value
If you look closely at the description of mediatype, then some strange parameter is indicated there. But, there is also a specification:
attribute := token
; Matching of attributes
; is ALWAYS case-insensitive.
value := token / quoted-string
token := 1*<any (US-ASCII) CHAR except SPACE, CTLs, or tspecials>
tspecials := "(" / ")" / "<" / ">" / "#" /
"," / ";" / ":" / "\" / <">
"/" / "[" / "]" / "?" / "="
; Must be in quoted-string,
; to use within parameter values
As can be seen, we can specify any parameter, the main thing is that it meets the requirements presented above!
Therefore, we can embed an additional attribute in the mediatype, which will not affect the image in any way, but the data url will differ from the same image.
Generalized algorithm:
We load the image through a regular request and remove the metadata from created dataUrl from blob.
fetch("https://cdn140.picsart.com/330970106009201.gif").then(async (res) => {
const blob = await res.blob();
const reader = new FileReader();
reader.onload = (ev) => {
// It would be reasonable to remove metadata to the point!
// But for simplicity, I'm using this implementation.
const dataUrl = ev.currentTarget.result.replace(
"data:image/gif;base64",
""
);
};
reader.readAsDataURL(blob);
});
Create/edit img element with src attribute "src=data:image/gif;base64;${Math.random()}${dataUrl}"
That is all!
Example Vanila JS
const url = "https://cdn140.picsart.com/330970106009201.gif";
function loadImage(src) {
fetch(src)
.then((res) => res.blob())
.then(async(blob) => {
const reader = new FileReader();
reader.onload = (ev) => {
const dataUrl = ev.currentTarget.result.replace("data:image/gif;base64", "")
const container = document.getElementById("container");
while (container.firstChild) {
container.firstChild.remove()
}
for (let i = 0; i < 6; i++) {
const img = document.createElement("img");
img.setAttribute("src", `data:image/gif;base64;gif-id=${Date.now()}${dataUrl}`)
container.appendChild(img);
img.addEventListener('click', ev => {
img.setAttribute("src", `data:image/gif;base64;gif-id=${Date.now()}${dataUrl}`)
})
}
};
reader.readAsDataURL(blob);
});
}
loadImage(url);
function updateImage() {
const newSrc = document.getElementById("image-src");
loadImage(document.getElementById("image-src").value);
}
#main {
display: flex;
flex-direction: column;
gap: 5px;
}
img {
width: 128px;
height: 128px;
padding: 5px;
}
<div id="main">
<label>Change gif url if current will become unavailable </label>
<input id="image-src" value="https://cdn140.picsart.com/330970106009201.gif"></input>
<button onclick="updateImage()">Update image source attribute</button>
<span>Click to reset!</span>
<div id="container">
</div>
</div>
Example React
import React, { useState, useRef } from "react";
function App() {
const [stars, setStars] = useState(0);
const [data, setData] = useState(null);
const ref = useRef(null);
React.useEffect(() => {
fetch("https://cdn140.picsart.com/330970106009201.gif")
.then((res) => res.blob())
.then(async (text) => {
const reader = new FileReader();
reader.onload = (ev) => {
setData(ev.currentTarget.result.replace("data:image/gif;base64", ""));
};
reader.readAsDataURL(text);
});
}, []);
return (
<React.Fragment>
<p onClick={() => setStars((s) => s + 1)}>+</p>
{data &&
new Array(stars).fill().map((s, ind) => {
return <Star src={data} key={ind}></Star>;
})}
<p onClick={() => setStars((s) => (s === 0 ? 0 : s - 1))}>-</p>
</React.Fragment>
);
}
export function Star(props) {
const [id] = useState(Math.random());
return (
<img
className="icon"
src={`data:image/gif;base64;gif-id=${id}` + props.src}
alt="animated star"
/>
);
}
export default App;
I came across this thread after searching many others. David Bell's post led me to the solution I needed.
I thought I'd post my experience in the event that it could be useful for anyone trying to accomplish what I was after. This is for an HTML5/JavaScript/jQuery web app that will be an iPhone app via PhoneGap. Testing in Chrome.
The Goal:
When user taps/clicks button A, an animated gif appears and plays.
When user taps/clicks button B, gif disappears.
When user taps/clicks button A again, after tapping/clicking button
B, animated gif should reappear and play from the beginning.
The Problem:
On tap/click of button A, I was appending the gif to an existing div. It would play fine.
Then, on tap/click of button B, I was hiding the container div, then setting the img src of the gif to an empty string (''). Again, no problem (that is, the problem wasn't evident yet.)
Then, on tap/click of button A, after tap/click of button B, I was re-adding the path to the gif as the src.
- This did not work. The gif would show up on subsequent taps/clicks of button A...however, the more I tapped/clicked button A, the more times the gif would load and start over. That is, if I went back and forth, tapping/clicking button A then button B 3 times, the gif would appear and then start/stop/start 3 times...and my whole app started to chug. I guess the gif was being loaded multiple times, even though I had set the src to an empty string when button B was tapped/clicked.
The Solution:
After looking at David Bell's post, I arrived at my answer.
I defined a global variable (let's call it myVar) that held the container div and the image (with the source path) within.
On the tap/click function of button A, I appended that container div to an existing parent div in the dom.
In that function, I created a new variable that holds the src path of the gif.
Just like David suggested, I did this (plus an append):
$('#mainParent').append(myVar);
var imgsrc = $('#my_image').attr('src');
$('#my_image').attr('src', '');
$('#my_image').attr('src', imgsrc);
THEN, in the function for button B, I set the src to an empty string and then removed the div containing the gif:
$('#my_image').attr('src', '');
$('#mainParent').find('#my_image').remove();
Now, I can tap/click button A then button B then button A, etc., all day long. The gif loads and plays on tap/click of button A, then hides on tap/click of button B, then loads and plays from the beginning on subsequent taps of button A every time with no issues.
I worked out a complete solution for this problem. It can be found here: https://stackoverflow.com/a/31093916/1520422
My solution restarts the animation WITHOUT re-loading the image data from the network.
It also enforces the image to repaint to fix some painting artefacts that occured (in chrome).
I hope somebody could help me out with this.
I'm working on a portfolio website that currently looks like this:
http://cargocollective.com/shap
As you can see, I have a png image over 15 animated gif thumbnails.
Basically, I want to have some short gif animations popping into some of the screens from a time to time, so what i'm trying to do is to have a script that replaces some of the gifs with others, either randomly OR after a certain amount of time.
I hope that someone can understand what i mean and help me.
__________ *UPDATE*:
Thanks a lot, I really appreciate the help. I'm sorry for the lack of knowladge I have, making it hard for me to use what you just wrote there, but this is what I added to my source code:
<script type="text/javascript">
$(document).ready(function() { changer(); });
function changer() {
var imgnum = Math.floor(15*Math.random());
var time = Math.floor(5000*Math.random());
var $img = $("img").eq(imgnum);
if ($img.attr("src")=="http://payload.cargocollective.com/1/1/39798/479556/prt_166x132_1314132436.gif")
$img.attr("src","http://payload.cargocollective.com/1/1/39798/479849/prt_166x132_1314132538.gif");
else
$img.attr("src","http://payload.cargocollective.com/1/1/39798/479556/prt_166x132_1314132436.gif");
setTimeout(changer,time);
}
</script>
I just copied the URL of 2 of my gif thumbnails and added them to the script, is that absolutely wrong?
Maybe the fact that I'm using the cargocollective system makes things complicated.
Here is what it looks like right now, as you can see, something IS happening, but I can't really control it:
http://cargocollective.com/shap
(after a minute the png overlay is gone for whatever reason)
best,
s
Tube televisions! How wonderfully quaint. ;-)
Well, here's something I tossed together. Obviously you should change the actual image SRCs into something that exists on your server.
http://jsfiddle.net/9KrsV/1/
$(function() { changer(); });
function changer() {
var imgnum = Math.floor(15*Math.random());
var time = Math.floor(5000*Math.random());
var $img = $("img").eq(imgnum);
if ($img.attr("src")=="images/chalk-dotted.png")
$img.attr("src","images/chalk-box.png");
else
$img.attr("src","images/chalk-dotted.png");
setTimeout(changer,time);
}
UPDATE: Obviously, this is pretty narrow. Here's another script that will store the old SRC and eventually flip back to it:
function changer() {
var imgnum = Math.floor(15 * Math.random());
var time = Math.floor(5000 * Math.random());
var $img = $("img").eq(imgnum);
var newsrc = "noisy_static.gif";
if ($img.attr("src") == newsrc) {
$img.attr("src", $img.data("oldsrc"));
} else {
$img.data("oldsrc",$img.attr("src"));
$img.attr("src", newsrc);
}
setTimeout(changer, time);
}