I tried js image changing example using two different if methods.
<img id="myImage" onclick="changeImage()" src="s.png">
Click image
<script>
function changeImage() {
var image = document.getElementById('myImage');
if (image.getAttribute('src')=='s.png')
image.src="m.png";
else
image.src="s.png";
}
</script>
Above method works totally fine no matter how many times clicked on the image or no matter which image is compared inside the 'if' part.
But below method which is given in w3c doesn't work as expected.
function changeImage(){
var image = document.getElementById('myImage');
if (image.src.match("s"))
{image.src ="m.png";}
else
{image.src ="s.png";}
This second method works only at first click. And also when the image compared inside the 'if' part is swapped with other image, it doesn't work at all even at the first click. Can someone please explain me, why second 'if' method doesn't work properly while first 'if' method works finely?
The reason why your code is not working is that web browser automatically adds site path to your image url because you are using relative image url. So you will have 's' character in every url (because s letter is in site url). And every .match('s') will always return true.
The solution is just to find out another checking of current image.
Here is example which logs out image src, so it should help you to understand the problem: https://jsfiddle.net/0yL0fwpL/4/
Html:
<img id="myImage" onclick="changeImage();" src="s.png">
Click image
Javascript:
changeImage = function() {
var image = document.getElementById('myImage');
if (image.getAttribute('src')=='s.png') {
image.setAttribute('src', "m.png");
} else {
image.setAttribute('src', "s.png");
}
}
Working example: https://jsfiddle.net/0yL0fwpL/2/
Related
Edit: Sorry if I reply late to any solutions because I need time to figure out how they work haha
I am a beginner in Javascript and I am currently trying to use this piece of code to change an image on mouseover
// Mouseover change (Ciel):
function rollover(my_image){
my_image.src = "images/ci2_a.png";
}
function mouseaway(my_image){
my_image.src = "images/ci_a.png";
}
and this is the corresponding HTML
<img src="images/ci_a.png" onmouseover="rollover(this)" onmouseout="mouseaway(this)" alt="xxx" style="float:left; width:38%">
This works fine, but I want to do it for more than one image on the same page (a different image rollover for each picture) . Even after changing the name of the functions and stuff it doesn't work. The first image stops changing onmouseover immediately when I try to add a similar function for the next image. Could someone tell me how to perform similar events on more than one image (not concurrently)? Thank you!
You could add event listeners to all the image elements you'd like.
<img class="my-image" src="images/ci_a.png" onmouseover="rollover(this)" onmouseout="mouseaway(this)" alt="xxx" style="float:left; width:38%"/>
function rollover(){
this.src = "images/ci2_a.png";
}
function mouseaway(){
this.src = "images/ci_a.png";
}
const myImages = document.querySelectorAll('.my-image')
myImages.forEach(img => {
img.addEventListener('mouseenter', rollover)
img.addEventListener('mouseleave', mouseaway)
})
You can send the image file as the second parameter like this:
function rollover(element, image) {
element.src = image
}
...
<img onmouseover="rollover(this, 'images/ci2_a.png')" ...>
But my question is why do you need JavaScript for that? You can use a simple CSS to achieve this.
Since you need different images on load and on hover, you need a single way to define this functionality across a collection of images.
Building on Matthew's approach, here's a way to do that.
JSFiddle to test it real-time.
You'll dynamically generate the images using data attributes to store the alternate (hover) image URL.
<img class="pics" src="https://picsum.photos/id/0/100"
data-swap="https://picsum.photos/id/10/100">
<br>
<img class="pics" src="https://picsum.photos/id/1/100"
data-swap="https://picsum.photos/id/11/100">
<br>
<img class="pics" src="https://picsum.photos/id/2/100"
data-swap="https://picsum.photos/id/12/100">
<br>
<img class="pics" src="https://picsum.photos/id/3/100"
data-swap="https://picsum.photos/id/14/100">
Then define the event listeners for all elements with the class pics. Here's a list of all the events that can be referenced.
On mouseover, store the original image in a data element original.
Then change the src with the value of the data-swap.
On mouseout, replace the src with the original value.
const myImages = document.querySelectorAll('.pics')
myImages.forEach(img => {
img.addEventListener('mouseover', function () {
img.dataset.original = img.src;
img.src = img.dataset.swap;
});
img.addEventListener('mouseout', function () {
img.src = img.dataset.original;
});
})
For some reason, when I use the attribute onload on my img tag, it causes my images to flicker. Ideally, when I load the page, an image is displayed and when I refresh the page, the image is changed.
Here's my tag as well as the function for it:
HTML
<img id="randomimage" onload="randomImg()" src="images/carmainpic.jpg" alt="main pic of car"/>
JavasScript
function randomImg(){
var images=["images/carmainpic.jpg","images/carmainpic2.jpg","images/carmainpic3.jpg"];
var num=Math.floor(Math.random()*3);
document.getElementById("randomimage").src=images[num];
}
Because the function you're calling changes the image's src to a random pick from the array, triggering a new load event, which changes the src randomly again, etc. On at least some browsers the cycle probably stops when you happen to assign the URL the image already has, too.
If your goal is to just show one of those images, at random, you can do that by leaving src off the img entirely and then adding it (once) with script (either immediately following the img in order to avoid your layout having to be adjusted when you add it, or in script at the end of the page if you prefer; no need to wait for any event):
<img id="randomimage" alt="main pic of car"/>
<script>
(function() {
var images=["images/carmainpic.jpg","images/carmainpic2.jpg","images/carmainpic3.jpg"];
var num=Math.floor(Math.random() * images.length); // <== Note change, so adding images to the array Just Works
document.getElementById("randomimage").src=images[num];
})();
</script>
Even if you put the script immediately after the <img ...> tag, the img element will be available to the script. So your choice whether to do it inline or with the other scripts at the end of the page.
The randomImg function is called every time the image loads. You can use a flag variable to make sure that you only change the image once:
var changed = false;
function randomImg(){
if (!changed) {
changed = true;
var images=["images/carmainpic.jpg","images/carmainpic2.jpg","images/carmainpic3.jpg"];
var num=Math.floor(Math.random()*3);
document.getElementById("randomimage").src=images[num];
}
}
The problem is that you are listening to the load event on the image, instead of the page.
onload="randomImg()"
So, as soon as the first image loads, it triggers the function randomImg which causes change of src attribute on the image. So the browser will attempt to assign a new image to the element, and yet another load event is triggered, which repeats the entire cycle.
Instead, if you want to choose a random image when the page loads, you can listen to DOMContentLoaded event on the document, and choose a random image.
document.addEventListener("DOMContentLoaded", function() {
var images=["images/carmainpic.jpg","images/carmainpic2.jpg","images/carmainpic3.jpg"];
var num=Math.floor(Math.random()*3);
document.getElementById("randomimage").src=images[num];
console.log("Showing: " + images[num]);
});
<img id="randomimage" src="images/carmainpic.jpg" alt="main pic of car"/>
Note: Since you are selecting a random image, it is not guaranteed that you will always get a different image when the page is refreshed. Instead, if you must get a different image on refreshing the page, you can perhaps persist the image identifier in localStorage, and use that to determine the next image to display.
Well you can use $(document).ready(function(){}) to do that. Because you want when charge the page that function execute it.
$(document).ready(function(){
function randomImg(){
var images=["https://www.bensound.com/bensound-img/romantic.jpg","https://www.psdstack.com/wp-content/uploads/2016/10/featured-copyright-free-mages.jpg","http://shaebaxter.com/wp-content/uploads/2015/04/Life-of-Pix-free-stock-photos-sea-peaople-water-waves-back-Sunset-Joshua-earle-1024x682.jpg"];
var num=Math.floor(Math.random()*3);
document.getElementById("randomimage").src=images[num];
}
randomImg();
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<img id="randomimage" src="" alt="main pic of car"/>
I have some javascript functionality that did work at one time, a few weeks ago, but wasn't crucial while I developed an application for my company, so I didn't notice when it seemed to simply stop working...but now it matters. It's a button which, when clicked, should display an image below the button. At present nothing happens when I click the button...though it used to properly display the image.
Here is the original code (in the head of the page):
function getImageFL()
{
var x = document.getElementById("flacBtn").value;
document.getElementById("flac_place").src=x;
}
And the the button tag (from the body of the page):
<button id="flacBtn" value="other_pages/images/flac.png" onclick="getImageFL()">Click for image of FLAC model</button><br>
<img id="flac_place" height="200" width="349" style="visibility:hidden">
Today I tried something else, for another button/image pair, but this doesn't seem to do anything either...the new code (also in head):
function getImageRW()
{
var x = document.getElementById("rwBtn").value;
var image = document.getElementById('rw_place');
image.setAttribute('src', x);
image.style.visibility='visible';
}
And in the button tag (in body):
<button id="rwBtn" value="other_pages/images/3D-3.png" onclick="getImageRW()">Click for image of RW model</button><br>
<img id="rw_place" height="170" width="425" style="visibility:hidden">
Any ideas why neither of these do a thing? And why the first one, at least, used to? Thanks!
The first one wouldn't work as you forgot to set visibility='visible'; on there
function getImageFL()
{
var x = document.getElementById("flacBtn").value;
document.getElementById("flac_place").src=x;
document.getElementById("flac_place").style.visibility = 'visible';
}
Fiddle here
The 2nd one works for me: http://jsfiddle.net/tTLf6/
I have been learning JavaScript and I have been doing some tasks, which I got in my college.
Tasks go like this:
Make a webpage, where 3 200x150 images and one 600x450 image will appear. Add JavaScript function, which will make sure, that the 600x450 image shown will be an enlarged image of an 200x150 image, on which we have pointed with a mouse previously (call the function with onMouseOver).
The second task goes like this:
Complete the webpage from task 1 in a way, when clicking the smaller image, the bigger image of the same image, we clicked will appear in a new window.
The code for the 1st task looks like this:
function bigImg(x)
{
x.style.height="600px";
x.style.width="450px";
}
function normalImg(x)
{
x.style.height="200px";
x.style.width="150px";
}
...
<img onmouseover="bigImg(this)" onmouseout="normalImg(this)" border="0" src="slika1.jpg" alt="slika1" width="150" height="200">
<img src="slika2.jpg">
<img src="slika3.jpg">
For the 2nd one like this:
function swipe()
{
var largeImage = document.getElementById('Slika1');
largeImage.style.display = 'block';
largeImage.style.width=450+"px";
// enter code here
var url=largeImage.getAttribute('src');
window.open(url,'Image','width=largeImage.style.width,height=largeImage.style.height,resizable=1');
}
...
<img src="slika1.jpg" id= "Slika1" onClick="swipe();"/>
<img src="slika2.jpg">
<img src="slika3.jpg">
What should be done differently?
<script>
function swipe(image)
{
newWidth=450+"px";
newHeight=600+"px";
var url=image.getAttribute('src');
myWindow=window.open('','Image','width='+newWidth+',height='+newHeight+',resizable=1');
myWindow.document.write('<img src="'+url+'" width="'+newWidth+'" height="'+newHeight+'" />');
}
</script>
<img src="slika1.jpg" onClick="swipe(this);"/>
<img src="slika2.jpg" onClick="swipe(this);"/>
<img src="slika3.jpg" onClick="swipe(this);"/>
To answer a few questions of the original poster:
The first parameter in the window.open() function here is '' (empty string), which basically creates a blank web page. The return value of this function call is the newly opened web page (which is assigned to the variable myWindow). You then drill down into that window object and call it's document.write() function to actually display the desired HTML (the image). In your original code you were simply opening a window that browsed to the image file (not an HTML page). Since that was the case, there is no way you could have actually set the width or height of the image--you were just setting (or trying to) the width and height of the window. Setting the width and height of the window wasn't even working in your example code because you didn't break the variable out of the string. So in the window.open() function you needed to pass a string in the third parameter that looked like:
width=450px,height=600px,resize=1
But what you were actually passing was:
width=largeImage.style.width,height=largeImage.style.height,resizable=1
The swipe() function we created takes in a single parameter "image". When we call this function from the onClick event inside the img tag we use the keyword "this" to pass a reference of itself. Essentially a copy of the img object that called swipe() is passed in as a parameter. So in the function, image.getAttribute('src') references the "src" attribute of the img object that called it, which you need to display in the opened window.
I've got a pretty simple problem, but I've become clueless on what is causing the problem. In one of my applications I'm using jCrop as a small add-on to crop images to fit in banners/headers etc. These steps will be taken:
1) Select an image (using CKFinder for this, CKFinder returns the image path to an input field)
2) Click a button to load the image
3) Crop the image
4) Save the image
in about 75% of the cases everything goes according to plan, however the in the other 25% of the cases jCrop fails to load the cropping area and leaves it blank. Here's the jQuery code I'm using:
jQuery('#selectimg').live('click', function(e) {
e.preventDefault();
var newsrc = jQuery('#img2').val();
jQuery('#cropbox').attr('src', newsrc);
var jcrop_api = jQuery.Jcrop('#cropbox', {
boxWidth: 700,
boxHeight: 700,
onSelect: updateCoords,
onChange: updateCoords
});
//Some other JS code come's here for buttons (they work all the time)
});
I noticed that when I left the part away where #cropbox is being transformd in a cropable area, that the image is loading just fine, so the mistake lies with the var = jcrop_api part, but I slowsly start to think that there is no solution for this...
This is what I've tried so far:
Making a div <div id="cropper-box"></div> and use jQuery('#cropper-box').append('<img src="" id="cropbox" />'); and afterwards set the value. I tried the same thing but setting the image src in 1 step instead of afterwards.
I tried to put a placeholder on the page <img src="placeholder.png" id="cropbox" /> and change the source upon clicking the button. This works, but the cropperarea stays the size of the image (300x180px or something) and doesn't get bigger as it should.
// Edit:
Trying some more showed me that the image source is being replaced properly(! using Firefox to show the source for the selected text), I double checked the URL but this was a correct URL and a working image.
At the place where the cropper should be, there's an about 10x10 pixel white spot where the cropper icon (a plus sign) is popping up.. but as said before: the image isn't shown.
// Edit 2:
So I've took the sources for both the 1st and the 2nd try for the same image. As told before the first try the image won't load properly and the 2nd try it does (only when the 2nd try is the same image(!!)).
The selected page source shows 1 difference which is, first try:
<img style="position: absolute; width: 0px; height: 0px;" src="http://95.142.175.17/uploads/files/Desert.jpg">
second try:
<img style="position: absolute; width: 700px; height: 525px;" src="http://95.142.175.17/uploads/files/Desert.jpg">
I guess this is the image that's being replace by jCrop, but it's a complete riddle why it puts 0 heigth/width in there the first and the proper sizes the second time.
Okay guys, in case anyone else runs into this problem:
jCrop kinda gets messed up if the actions of loading an image and applying jCrop to it are queued too fast after eachother. I still find it strange that a second attempt works perfect, but I think that has something to do with cached image dimensions which are recognized by the DOM of the page or something.
The solution I came up with was by creating a function that converts the #cropbox into a jCrop area and then setting a 2 second interval, just to give jCrop some time to recognize the image and it's dimensions and then convert the element.
This is the part of html I used (with a preloader):
<div id="cropper-loading" style="display: none;"><img src="images/analytics/ajax-loader.gif" /></div>
<img id="cropbox" src="images/placeholder.png" style="display: none;" />
As you can see both the cropbox image and cropper-loading div are hidden as they are not needed instantly. You could display the placeholder if you wanted though.. Then this HTML form is used:
<input name="image2" id="img2" type="text" readonly="readonly" onclick="openKCFinder(this)" value="click here to select an image" style="width: 285px;" /> <button class="button button-blue" type="submit" name="load" id="selectimg">Load Image in cropper</button>
In my case I've been using KCFinder to load the images (it's part of CKEditor, really worth watching into!), KCFinder handles uploads, renaming etc and after choosing it returns the chosen image path (relative/absolute is configurable) to the input field.
Then when clicking #selectimg this code is called:
jQuery('#selectimg').click(function(e) {
e.preventDefault();
jQuery('#cropper-loading').css('display', 'block');
var newsrc = jQuery('#img2').val();
jQuery('#cropbox').attr('src', newsrc);
jQuery('#img').val(newsrc);
function createJcropArea() {
jQuery('#cropper-loading').css('display', 'none');
jQuery('#cropbox').css('display', 'block');
var jcrop_api = jQuery.Jcrop('#cropbox', {
boxWidth: 700,
boxHeight: 700,
onSelect: updateCoords,
onChange: updateCoords
});
clearInterval(interval);
}
var interval = setInterval(createJcropArea, 2000);
});
At first I prevent the link too be followed as it normally would (or button action) and after that the loading div is displayed (that's my reason for hiding the placeholder image, otherwise it would look messed up).
Then the image location is being loaded from the input field and copied into another (#img), this field is used to process the image afterwards (PHP uses the value of #img to load this image). Also simultaneously the #cropbox src is being set to the new image.
And here comes the part which solved my problem:
Instead of directly activating jCrop, I've made a function that:
1) hides the loading icon
2) displays the image
3) converts #cropbox into a jCrop area
4) clean the interval (otherwise it would loop un-ending)
And after this function you can see that, just to be save, I took 2 seconds delay before the jCrop area is being converted.
Hope it helps anyone in the future!
Cheers and thanks for thinking #vector and whoever else did ;-)
Creating an 'Image' object and setting up the 'src' attribute does not apply that you can treat the image like it had already been loaded.
Also, giving any fixed timeout interval does not guaranty the image has already been loaded.
Instead, you should set up an 'onload' callback for the Image Object - which will then initialize the Jcrop Object:
var src = 'https://example.com/imgs/someimgtocrop.jpg';
var tmpImg = new Image();
tmpImg.onload = function() {
//This is where you can safely create an image and a Jcrop Object
};
tmpImg.src = src; //Note that the 'src' attribute is only added to the Image Object after the 'onload' listener was defined
Try the edge library on the repo here: https://github.com/tapmodo/Jcrop
This should solve your problem. The lines that are changed to solve your problem:
// Fix size of crop image.
// Necessary when crop image is within a hidden element when page is loaded.
if ($origimg[0].width != 0 && $origimg[0].height != 0) {
// Obtain dimensions from contained img element.
$origimg.width($origimg[0].width);
$origimg.height($origimg[0].height);
} else {
// Obtain dimensions from temporary image in case the original is not loaded yet (e.g. IE 7.0).
var tempImage = new Image();
tempImage.src = $origimg[0].src;
$origimg.width(tempImage.width);
$origimg.height(tempImage.height);
}
Don't call this function onChange : updateCoords
Try it without and it will run smooth on mobiles.
You can create base64 directly and show them as an image wherever you want.
Here my weird but fantastic solution:
if (obj.tagName == 'IMG') {
var tempImage = new Image();
tempImage.src = $origimg[0].src;
$origimg.width(tempImage.width);
$origimg.height(tempImage.height);
if ($origimg[0].width > 1 && $origimg[0].height > 1) {
$origimg.width($origimg[0].width);
$origimg.height($origimg[0].height);
} else {
var tempImage = new Image();
tempImage.src = $origimg[0].src;
$origimg.width(tempImage.width);
$origimg.height(tempImage.height);
//console.log('error'+$origimg[0].width + $origimg[0].height);
}
I know this is old, but it was happening randomly to my install recently. Found that it was due to images not being full loaded before before jCrop intialized.
All it took to fix it was wrapping the jCrop initialization stuff inside of a
$(window).on("load", function () { //jcrop stuff here });
And it has been working well since.