How to set src to each shuffled image in javascript? - javascript

I'm trying to shuffle images from array to a specific div.
<body>
<div id="set"></div>
</body>
<script>
var ArrayOfImages = ['bar.jpg',
'foo.jpg',
'koo.jpg',
'too.jpg'
];
var set = document.getElementById("set");
set.addEventListener("click", randomize, false);
ArrayOfImages.forEach(function(image) {
var elem = document.createElement('img');
elem.src = image;
set.appendChild(elem);
});
function shuffle(array) {
let counter = array.length;
// While there are elements in the array`enter code here`
while (counter > 0) {
// Pick a random index
let index = Math.floor(Math.random() * counter);
// Decrease counter by 1
counter--;
// And swap the last element with it
let temp = array[counter];
array[counter] = array[index];
array[index] = temp;
}
return array;
}
function randomize() {
set.innerHTML = shuffle(ArrayOfImages);
}
</script>
Now the problem is, that innerHTML only changes the text of the image but cannot set an src to it. Though it does the shuffle.
Any help would be appreciated!

.innerHTML will change the actual HTML, not the images src which is what you want to change.
At the moment you are getting your image elements from your HTML using
document.getElementById('set)
however, you HTML can only have one element with the id set. Thus, you can use the class attribute instead to give multiple elements the identifier of 'set' and get all your image elements using:
document.getElementsByClassName('set')
which will return a collection of your HTML image tags. Now, to change each image's source you can loop over this collection or loop over your shuffled images and set each image's source.
See an example below for further clarification:
var img_elems = document.getElementsByClassName('set'); // Get all elements to set the image to
// To go into your randomize() function:
// Shuffled images returned via your shuffle() function
var shuffled_images = ['https://images.pexels.com/photos/34950/pexels-photo.jpg?auto=compress&cs=tinysrgb&h=350', 'https://www.pandotrip.com/wp-content/uploads/2018/09/Seigantoji-Pagoda-and-Nachi-Falls-in-Nacho-Japan.jpg', 'https://www.elastic.co/assets/bltada7771f270d08f6/enhanced-buzz-1492-1379411828-15.jpg'];
for (var i = 0; i < shuffled_images.length; i++) {
img_elems[i].src = shuffled_images[i]; // Set the image to the src value.
}
/* Ignore this */
img {
height: 200px;
width: 200px;
}
<img src="" class="set" /><br />
<img src="" class="set" /><br />
<img src="" class="set" />

More clean and better way of doing it in vanilla javascript.
The issue was in your shuffle function.
var image_swap_tool = function(options){
var self = this;
self.ArrayOfImages = options.ArrayOfImages;
self.image_container_elem = document.getElementById("set");
self.image_container_elem.addEventListener("click", function(){
self.randomize();
});
}
image_swap_tool.prototype.create_image = function(){
var self = this;
var images = self.ArrayOfImages;
var image_container = self.image_container_elem;
image_container.innerHTML = '';
for(var i=0; i < images.length;i++){
var img = document.createElement('img');
img.setAttribute('src',images[i]);
image_container.appendChild(img);
}
};
image_swap_tool.prototype.shuffle = function(){
var self = this;
var images = self.ArrayOfImages;
let counter = images.length;
while (counter > 0) {
// Pick a random index
let index = Math.floor(Math.random() * counter);
// Decrease counter by 1
counter--;
// And swap the last element with it
let temp = images[counter];
images[counter] = images[index];
images[index] = temp;
}
//Set new order back to images for next time
self.ArrayOfImages = images;
//Images are shuffled then append them again
self.create_image();
}
image_swap_tool.prototype.randomize = function(){
var self = this;
var image_container = self.image_container_elem;
self.shuffle();
}
var options = {};
options.ArrayOfImages = ['bar.jpg', 'foo.jpg', 'koo.jpg', 'too.jpg'];
var tool = new image_swap_tool(options);
tool.create_image();
Thanks

Related

I don't how why my backgroundImage doesn't work

Why does my banner doesn't change her background? Please help me.
When I run the file the console tells me:
Uncaught TypeError: flechedroite.addEventListener is not a function
I really don't understand. I'm a beginner in Javascript so please explain me with kind words how I can fix this error :)
var flechedroite = document.getElementsByClassName('fa-arrow-right');
var flechegauche = document.getElementsByClassName('switch-left');
var banner = document.getElementById('banner');
var images = [];
var changeBackground = function (bElement, bUrl) {
return bElement.style.backgroundImage = "url(" + bUrl + ")";
}
//image list
images[0] = 'images/image1.jpg';
images[1] = 'images/image2.jpg';
images[2] = 'images/image3.jpg';
flechedroite.addEventListener('click', function() {
for (var i = 0; i < images.length; i++) {
changeBackground(document.body, images[i]);
}
})
addEventListener should be called in window.onload or in $(document).ready()
Since getElementsByClassName returns an array, you need to use array index with flechedroite to add an event listener. i.e. flechedroite[0].addEventListener('click', function() {...});
You are calling changeBackground function in a loop to set the background image, effectively you will see only the last image from the array being set as background.
JS Code
var images = [];
var changeBackground = function (bElement, bUrl) {
return bElement.style.backgroundImage = "url("+bUrl+")";
}
//image list
images[0] = 'https://www.gettyimages.ie/gi-resources/images/Homepage/Hero/UK/CMS_Creative_164657191_Kingfisher.jpg';
images[1] = 'https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTOGUhZo0Qe81U5qY_Z-seXgsD79LEEet832TVOlLMOEy10ZPsV';
images[2] = 'https://cdn.pixabay.com/photo/2016/06/18/17/42/image-1465348_960_720.jpg';
window.onload = function(){
var flechedroite = document.getElementsByClassName('fa-arrow-right');
var flechegauche = document.getElementsByClassName('switch-left');
var banner = document.getElementById('banner');
var currentImageIndex = 0;
flechedroite[0].addEventListener('click', function() {
currentImageIndex = (currentImageIndex+1)%images.length;
changeBackground(document.body, images[currentImageIndex]);
})
}
The function getElementsByClassName returns a HTMLCollection, which is an array like structure that can contain multiple elements. So you need to use an index to access the elements contained in it.
So flechedroite.addEventListener results in an error but flechedroite[0].addEventListener should work
https://developer.mozilla.org/en-US/docs/Web/API/Element/getElementsByClassName
if you use 'getElementsByClassName' and you want to add an 'addEventListener', you can not do it in a 'generic' way: "flechedroite.addEventListener ('click', function () {}". You have to do this for each element:
var flechedroite = document.getElementsByClassName('fa fa-arrow-right');
//flechedroite contains all the elements that have the 'fa fa-arrow-right' classes
//on each element you have to add the "addEventListener"
for (var i = 0; i < flechedroite.length; i++) {
flechedroite[i].addEventListener('click', function() {
alert('flechedroite');
});
}
basic example JSFiddle1
a more advanced example
JSFiddle2

JavaScript change img src

I am trying to make an image slider just using JavaScript. I have a button with an id in HTML and want to change the src of the button based on a position in an array. This is my following code.
var index = 0;
var imageArray = [{'images/img1.jpg'},{'images/img2.jpg'},{'images/img3.jpg'},{'images/img4.jpg'}];
function moveToNextSlide()
{
if (index >= imageArray.length -1)
{
index =-1;
}
var img = getElementById(img_start);
index = index + 1;
var currentSlide = imageArray[index];
getElementByid(img_start).src="currentSlide";
}
Looks like you're trying to create an array of strings. You have:
var imageArray = [{'images/img1.jpg'},{'images/img2.jpg'},{'images/img3.jpg'},{'images/img4.jpg'}];
Braces ({}) are used to declare objects; the braces you have around each string are a syntax error. For just an array of strings, simply leave the quoted literals without braces:
var imageArray = ['images/img1.jpg','images/img2.jpg','images/img3.jpg','images/img4.jpg'];
There are a few issues. Firstly, you need to use the correct array syntax.
var imageArray = ['images/img1.jpg','images/img2.jpg','images/img3.jpg','images/img4.jpg'];
Also, you need to use document.getElementById and set as getElementById on it's own will refer to the window, not the document.
Finally, you need to set to the variable currentSlide like so img.src= currentSlide;, not "currentSlide" as a string.
function moveToNextSlide(){
if (index >= imageArray.length -1){
index =-1;
}
var img = document.getElementById('img_start');
index = index + 1;
var currentSlide = imageArray[index];
img.src= currentSlide;
}
See full example here
var index = 0;
var imageArray = ['http://www.profightdb.com/img/wrestlers/thumbs-600/1414330df8brethart.jpg', 'http://armpit-wrestling.com/wp-content/uploads/2016/06/bret-hart.jpg'];
document.body.onload = function(){
document.getElementById('img_start').src = imageArray[0];
};
function moveToNextSlide() {
if (index >= imageArray.length - 1) {
index = -1;
}
var img = document.getElementById('img_start');
index = index + 1;
var currentSlide = imageArray[index];
img.src = currentSlide;
}
img {
max-width: 100px;
}
p {
cursor: pointer;
}
<img id="img_start" src="">
<p onclick="moveToNextSlide()">Click Here</p>

easier way to code series of images javascript

In the code below, I've successfully made it so when someone clicks on a thumbnail of a picture, it's full picture will come up in the target.
I was wondering if anyone knew of a nicer way to create onclick events for multiple thumbnails I would like to make this expandable.
Also, please consider only javaScript answers as I don't write in jQuery (yet!).
var img = document.getElementById("galleryImg");
var thumb = document.getElementsByClassName("imgThumb");
var p0 = "https://dl.dropboxusercontent.com/u/89495286/test/images/pic1.png";
var p1 = "https://dl.dropboxusercontent.com/u/89495286/test/images/pic2.png";
var p2 = "https://dl.dropboxusercontent.com/u/89495286/test/images/pic3.png";
var p3 = "https://dl.dropboxusercontent.com/u/89495286/test/images/pic4.png";
var p4 = "https://dl.dropboxusercontent.com/u/89495286/test/images/pic5.png";
var p5 = "https://dl.dropboxusercontent.com/u/89495286/test/images/pic6.png";
var pArray = [p0, p1, p2, p3, p4, p5]
img.src = pArray[0];
thumb[0].onclick = function(){pic0()};
function pic0(){img.src = pArray[0]};
thumb[1].onclick = function(){pic1()};
function pic1(){img.src = pArray[1]};
thumb[2].onclick = function(){pic2()};
function pic2(){img.src = pArray[2]};
thumb[3].onclick = function(){pic3()};
function pic3(){img.src = pArray[3]};
thumb[4].onclick = function(){pic4()};
function pic4(){img.src = pArray[4]};
thumb[5].onclick = function(){pic5()};
function pic5(){img.src = pArray[5]};
Assuming that you'll have the same amount of elements in pArray as you would have thumbnails, you would do this:
Array.prototype.forEach.call(thumb, function(thumbItem, index) {
thumbItem.onclick = function() {
img.src = pArray[index];
};
});
It iterates through the thumbnails, attaching the onclick handler and assigning the main image with the corresponding image based on the element's index.
You could use the loop for any array, we usually use the for loop for related arrays.
for (var i = 0; i < thumb.length; i++) {
thumb[i].src = pArray[i]; // change if different src
thumb[i].onclick = function() { img.src = this.src; };
}
Try on: https://jsfiddle.net/Zay_DEV/8r1gqnfx/
var img = document.getElementById("galleryImg");
var thumb = document.getElementsByClassName("imgThumb");
var pArray = [
"https://dl.dropboxusercontent.com/u/89495286/test/images/pic1.png",
"https://dl.dropboxusercontent.com/u/89495286/test/images/pic2.png",
"https://dl.dropboxusercontent.com/u/89495286/test/images/pic3.png",
"https://dl.dropboxusercontent.com/u/89495286/test/images/pic4.png",
"https://dl.dropboxusercontent.com/u/89495286/test/images/pic5.png",
"https://dl.dropboxusercontent.com/u/89495286/test/images/pic6.png"
]
for (var i = 0; i < thumb.length; i++) {
thumb[i].src = pArray[i];
thumb[i].onclick = function() { img.src = this.src; };
}
thumb[0].onclick();
#galleryImg { max-height: 25vh; }
.imgThumb { width: 100px; height: 50px; }
<img id="galleryImg"/>
<br />
<img class="imgThumb"/>
<img class="imgThumb"/>
<img class="imgThumb"/>
<img class="imgThumb"/>
<img class="imgThumb"/>
<img class="imgThumb"/>
You iterate over the array, however, using a loop alone will not completely fix the problem, because you're assigning a function inside the loop, which means any outside variables could change before the onclick executes.
So what you need is a closure.
Create a function that sets the onclick callback
Call that function in a loop.
Here's an example:
function setOnClick(element, imgSrc) {
element.onclick = function() { img.src = imgSrc; };
}
for (var i = 0; i < thumb.length; i++) {
setOnClick(thumb[i], pArray[i]);
}
This functionality is very common, so it has also been implemented by Array#forEach:
pArray.forEach(function(imgSrc, index) {
thumb[index].onclick = function() { img.src = imgSrc; };
});

Passing image array values and changing image source onclick

OK, so finally the penny dropped (loud clunk!) on the click issue I was having here Append dynamic div just once and a JSFiddle issue. The code now shows user a choice of pics once per node clicked. Phew.
However, now my img.src=e.target.src line is having trouble accessing the other images in the array. Only the last image in the array will add to the table. I think this is because the allImages.onclick event should be inside the loop?
I have tried that and then img is showing up as undefined. I'm guessing that is because the loop (and therefore the function) is running before var img is declared? I think it is an issue with the order of things.
All help appreciated.
var makeChart = function () {
var table = document.createElement('table'),
taskName = document.getElementById('taskname').value,
header = document.createElement('th'),
numDays = document.getElementById('days').value, //columns
howOften = document.getElementById('times').value, //rows
row,
r,
col,
c;
var myImages = new Array();
myImages[0] = "http://www.olsug.org/wiki/images/9/95/Tux-small.png";
myImages[1] = "http://a2.twimg.com/profile_images/1139237954/just-logo_normal.png";
for (var i = 0; i < myImages.length; i++) {
var allImages = new Image();
allImages.src = myImages[i];
var my_div = document.createElement("div");
my_div.id = "showPics";
document.body.appendChild(my_div);
var newList = document.createElement("ul");
newList.appendChild(allImages);
my_div = document.getElementById("showPics");
my_div.appendChild(newList);
my_div.style.display = 'none';
}
header.innerHTML = taskName;
table.appendChild(header);
header.innerHTML = taskName;
table.appendChild(header);
function addImage(col) {
var img = new Image();
img.src = "http://cdn.sstatic.net/stackoverflow/img/tag-adobe.png";
col.appendChild(img);
img.onclick = function () {
my_div.style.display = 'block';
allImages.onclick = function (e) { // I THINK THIS IS THE PROBLEM
img.src = e.target.src;
my_div.style.display = 'none';
img.onclick=null;
};
}
}
for (r = 0; r < howOften; r++) {
row = table.insertRow(-1);
for (c = 0; c < numDays; c++) {
col = row.insertCell(-1);
addImage(col);
}
}
document.getElementById('holdTable').appendChild(table);
document.getElementById('createChart').onclick=null;
}
Well, the problem seems to stem from different parts. First of all,
for (var i = 0; i < myImages.length; i++) {
var allImages = new Image();
allImages.src = myImages[i];
var my_div = document.createElement("div");
my_div.id = "showPics";
document.body.appendChild(my_div);
var newList = document.createElement("ul");
newList.appendChild(allImages);
my_div = document.getElementById("showPics");
my_div.appendChild(newList);
my_div.style.display = 'none';
}
This loop creates a new div for EACH image in myImages, then appends a ul to that div, and finally appends the Image for the current image to the ul.
The question of what document.getElementById('showPics') returns, since there are as many divs with the id showPics appended to body as myImages.length, has a mystical magical answer which should never be spoken, or even thought, of again.
Why not do the sensible thing and create one singular happy div outside the loop? Append a single ul child to it, outside the loop. Then proceed to append as many li as you want in the loop.
var my_div = document.createElement('div');
my_div.id = 'showPics';
var newList = document.createElement('ul');
my_div.appendChild(newList);
for var i = 0; i < myImages.length; i++) {
...
var li = document.createElement('li');
li.appendChild(allImages);
newList.appendChild(li);
...
}
my_div.style.display = 'none';
Now, my_div is the one and only div containing the images. So, the click event handlers can toggle its visibility safely.
Second,
function addImage(col) {
var img = new Image();
img.src = "http://cdn.sstatic.net/stackoverflow/img/tag-adobe.png";
col.appendChild(img);
img.onclick = function () {
my_div.style.display = 'block';
allImages.onclick = function (e) { // I THINK THIS IS THE PROBLEM
img.src = e.target.src;
my_div.style.display = 'none';
img.onclick=null;
};
}
}
allImages references the same Image object now that you are out of the loop, which happens to be the last image in myImages. So, only the last image in myImages will register the handler to a click event. To solve this problem, we make a new variable.
var sel = null; //This comes before my_div
Now, we add the click handler to allImages inside the loop so that every image in myImages gets a piece of the pie, as they say.
for var i = 0; i < myImages.length; i++) {
var allImages = new Image();
allImages.src = myImages[i];
allImages.onclick = function (e) {
if(sel !== null) {
sel.src = e.target.src;
my_div.style.display = 'none';
sel.onclick=null;
sel = null;
}
};
...
}
And finally, adjust addImage so that sel can be set when the image is clicked.
function addImage(col) {
...
img.onclick = function () {
my_div.style.display = 'block';
sel = img;
}
...
}
That's all there is to it! Example.
Note that, if you comment out sel.onclick = null, you can change a particular cell's image as many times you like.
Your addImage() function makes a direct reference to the allImages variable. One problem is that since you were using (and reusing) that variable in a for loop earlier in the code it is only going to retain the last value that was assigned to it. So no matter how many times you call addImage() it's always adding the onclick function to the last image that allImages pointed to.
I'd also suggest renaming the allImages variable. That's a very misleading name because it in fact only ever represents a single image.
Hope that helps!

How to check if the image is loaded?

with ajax i get an array of pictures URL and then I need to create from them the gallery. I also need to make a counter that shows the number of downloaded images, it looks like this:
var images;
var load_image = new Image();
load_image.onload = function(){
myPhotoSwipe.show(0);
}
$.each(images['images'], function(key, value) {
load_image.src = ('index.php?load_image=' + value);
$('#image_count').remove();
$('span[class="loading"]').after('<div id="count"><h6>Images: ['+key+' / '+images_array['images'].length+']</h6></div>');
images+= '<li><img src="index.php?load_image='+value+'" /></li>';
});
The problem is that the counter is always loaded at penultimate element and stay there until all images are loaded, but I need to show the load of each like a progress.
P.S.
I also tried complete, but it didn't help.
This should fix it. The reason is because the load handler was being bound to only 1 image object.
var images;
$.each(images['images'], function(key, value) {
var load_image = new Image();
load_image.src = ('index.php?load_image=' + value);
$('#image_count').remove();
$('span[class="loading"]').after('<div id="count"><h6>Images: ['+key+' / '+images_array['images'].length+']</h6></div>');
images+= '<li><img src="index.php?load_image='+value+'" /></li>';
load_image.onload = function(){
myPhotoSwipe.show(0);
}
});
You are almost there.
The problem is that you are re-using the same image object. You need to create an array of load_image instances and increment your counter inside onload, when each of them returns.
function load(){
var imageUrls = [];
imageUrls.push('http://www.nasa.gov/images/content/690106main_iss033e005644_full.jpg');
imageUrls.push('http://www.nasa.gov/images/content/690669main_201209210010_full.jpg');
imageUrls.push('http://www.nasa.gov/images/content/691806main_hs3_full_full.jpg');
imageUrls.push('http://www.nasa.gov/images/content/689231main_Webb_Mirror_Cans_orig_full.jpg');
var images = [];
var i;
var counter = 0;
var mainDiv = document.getElementById('somediv');
var counterDiv = document.getElementById('counter');
for (i = 0; i < imageUrls.length; i++)
{
images[i] = new Image();
images[i].width = 100;
images[i].height = 100;
images[i].onload = function () {
counter++;
counterDiv.innerText = counter;
}
mainDiv.appendChild(images[i]);
images[i].src = imageUrls[i];
}
}

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