I'm in such a situation where i need to wait till the image gets loaded once the image gets loaded i need to gets its computed height so that i can set the yellow color selector accordingly.
Question: based on computed height of image i'm setting yellow color selector. it works with setTimeout() randomly but i don't want such approach.
let images = ['https://via.placeholder.com/150','https://via.placeholder.com/110/0000FF/808080%20?Text=Digital.com','https://via.placeholder.com/80/0000FF/808080%20?Text=Digital.com'];
let image = `<img src="${images[Math.floor(Math.random()*images.length)]}"/>`
document.getElementById('content').innerHTML = `<div class="box">${image}</div>`;
//actual code
let height = window.getComputedStyle(document.querySelector('.box'), null).getPropertyValue('height');
let imageWidth = window.getComputedStyle(document.querySelector('.box img'), null).getPropertyValue('width');
console.log('height',height,'width',imageWidth);
wrapImage = `<div style="width:calc(${imageWidth} + 10px);height:calc(${height} + 10px);position:absolute;left:0;top:0;border:1px solid yellow;"></div>`;
document.querySelector('.box').insertAdjacentHTML('beforeend',wrapImage);
.box{
width:100%;
height:auto;
border:1px solid red;
position:relative;
}
<div id="content">
</div>
with setTimeout it works but i don't want such approach,i want callback or some event once element is ready
let images = ['https://via.placeholder.com/150','https://via.placeholder.com/110/0000FF/808080%20?Text=Digital.com','https://via.placeholder.com/80/0000FF/808080%20?Text=Digital.com'];
let image = `<img src="${images[Math.floor(Math.random()*images.length)]}"/>`
document.getElementById('content').innerHTML = `<div class="box">${image}</div>`;
//actual code
setTimeout(() => {
let height = window.getComputedStyle(document.querySelector('.box'), null).getPropertyValue('height');
let imageWidth = window.getComputedStyle(document.querySelector('.box img'), null).getPropertyValue('width');
console.log('height',height,'width',imageWidth);
wrapImage = `<div class="select" style="width:calc(${imageWidth} + 10px);height:${height};position:absolute;left:0;top:0;border:1px solid yellow;"></div>`;
document.querySelector('.box').insertAdjacentHTML('beforeend',wrapImage);
document.querySelector('.select').height = document.querySelector('.select').height + 10;
console.log('after computed height and added 10px',window.getComputedStyle(document.querySelector('.box'), null).getPropertyValue('height'));
},700);
.box{
width:100%;
height:auto;
border:1px solid red;
position:relative;
}
<div id="content">
</div>
Please help me thanks in advance !!!
The image hasn't finished loading when you retrieved the height and width. To solve this, you'll need to wait for the images to load first, then get their height and width.
Listen for the window load event, which will fire when all resources (including images) have loaded completely:
let images = ['https://via.placeholder.com/150', 'https://via.placeholder.com/110/0000FF/808080%20?Text=Digital.com', 'https://via.placeholder.com/80/0000FF/808080%20?Text=Digital.com'];
let image = `<img src="${images[Math.floor(Math.random()*images.length)]}"/>`
document.getElementById('content').innerHTML = `<div class="box">${image}</div>`;
//actual code
window.addEventListener('load', function() {
let height = window.getComputedStyle(document.querySelector('.box'), null).getPropertyValue('height');
let imageWidth = window.getComputedStyle(document.querySelector('.box img'), null).getPropertyValue('width');
console.log('height', height, 'width', imageWidth);
wrapImage = `<div class="select" style="width:calc(${imageWidth} + 10px);height:${height};position:absolute;left:0;top:0;border:1px solid yellow;"></div>`;
document.querySelector('.box').insertAdjacentHTML('beforeend', wrapImage);
document.querySelector('.select').height = document.querySelector('.select').height + 10;
console.log('after computed height and added 10px', window.getComputedStyle(document.querySelector('.box'), null).getPropertyValue('height'));
});
.box {
width: 100%;
height: auto;
border: 1px solid red;
position: relative;
}
<div id="content">
</div>
To indicate selection you can use CSS outline property. That way you won't have to manage selection dimensions yourself.
Following is demo code. As you want to do it over multiple images, I've added 3 images. And you can select multiple images.
function changeImages() {
var images = document.getElementsByTagName('img');
for (var i = 0; i < images.length; i++) {
images[i].src = "https://via.placeholder.com/" + Math.floor(Math.random() * 50 + 50).toString() + "/0a0a0a/ffffff";
}
}
function setClickEvents() {
var images = document.getElementsByTagName('img');
for (var i = 0; i < images.length; i++) {
images[i].addEventListener("click", function(event) {
event.target.classList.toggle("selected");
});;
}
}
function init() {
document.getElementById('content').innerHTML = `<div id="box"></div>`;
var box = document.getElementById('box');
var img = document.createElement("img");
img.classList.add("selected");
box.appendChild(img);
box.appendChild(document.createElement("img"));
box.appendChild(document.createElement("img"));
setClickEvents();
changeImages();
}
#content {
padding: 15px;
margin: 10px;
}
#box {
width: 100%;
height: 120px;
border: 1px dotted red;
position: relative;
}
img {
margin: 15px;
}
/* use this class for marking selected elements */
.selected {
outline: thick double #f7d205;
outline-offset: 7px;
}
<!DOCTYPE html>
<html lang="en">
<body onload="init()">
<button onclick="changeImages()">Change Images</button>
<div id="content"></div>
</body>
</html>
Click on image to toggle selection.
If you want more flexibility then you can use Resize Observer. With this when you change src attribute of image tag you'll able to change selection size.
const imageObserver = new ResizeObserver(function(entries) {
for (let entry of entries) {
var img = entry.target;
let height = img.height + 10;
let width = img.width + 10;
console.log('Added 10px. height:', height, ' width:', width);
wrapImage = `<div class="select" style="width:${width}px;height:${height}px;position:absolute;left:0;top:0;border:1px solid #f7d205;"></div>`;
document.querySelector('.box').insertAdjacentHTML('beforeend', wrapImage);
}
});
function init() {
document.getElementById('content').innerHTML = `<div id="box" class="box"></div>`;
var box = document.getElementById('box');
var img = document.createElement("img");
img.src = "https://via.placeholder.com/" + Math.floor(Math.random() * 50 + 80).toString() + "/0a0a0a/ffffff";
box.appendChild(img);
imageObserver.observe(img);
}
<!DOCTYPE html>
<html lang="en">
<style>
#box {
width: 100%;
border: 1px dotted red;
position: relative;
}
</style>
<body onload="init()">
<div id="content"></div>
</body>
</html>
Note: Using same ResizeObserver you can observe multiple images:
var images = document.getElementsByTagName('img');
for (var i = 0; i < images.length; i++) {
imageObserver.observe(images[i]);
}
Edit: As requested, demonstrating observing img resize from parent div element. Here the image is wrapped in div #box. On resize img dispatches a custom event and parent handles it.
function handleChildResize(event) {
console.log('parent: got it! handling it.. ')
var img = event.data;
let height = img.offsetHeight + 10;
let width = img.offsetWidth + 10;
console.log('Added 10px. height:', height, ' width:', width);
wrapImage = `<div class="select" style="width:${width}px;height:${height}px;position:absolute;left:0;top:0;border:2px solid #f7d205;"></div>`;
if (document.querySelector('.box > .select')) {
document.querySelector('.box > .select').remove();
}
document.querySelector('.box').insertAdjacentHTML('beforeend', wrapImage);
event.stopPropagation();
}
const imgObserver = new ResizeObserver(function(entries) {
for (let entry of entries) {
var img = entry.target;
var event = new Event('childResized');
event.data = img;
console.log("img: i am resized. Raising an event.");
img.dispatchEvent(event);
}
});
function init() {
var box = document.getElementById('box');
box.addEventListener('load', (event) => {
console.log('The page has fully loaded');
});
var img = document.createElement("img");
img.src = "https://via.placeholder.com/" + Math.floor(Math.random() * 50 + 80).toString() + "/0a0a0a/ffffff";
box.appendChild(img);
imgObserver.observe(img);
box.addEventListener('childResized', handleChildResize, true);
}
<!DOCTYPE html>
<html>
<head>
<style>
#box {
width: 100%;
padding: 10px;
border: 1px solid red;
position: relative;
}
</style>
</head>
<body onload="init()">
<div id="content">
<div id="box" class="box"></div>
</div>
</body>
</html>
You could consider adding the 'load' event listener as a callback for image loading.
Please check the example:
const image = document.getElementById('image');
const handler = () => {
alert(image.height);
};
image.addEventListener('load', handler);
<img src="https://image.shutterstock.com/z/stock-vector-sample-stamp-grunge-texture-vector-illustration-1389188336.jpg" id="image" />
I see that you want to compute the final value of the get computed style
you see. The thing is that the getComputedStyle doesn't get updated.
So just make a function to do it!
let images = ['https://via.placeholder.com/150','https://via.placeholder.com/110/0000FF/808080%20?Text=Digital.com','https://via.placeholder.com/80/0000FF/808080%20?Text=Digital.com'];'
let image = `<img src="${images[Math.floor(Math.random()*images.length)]}"/>`
document.getElementById('content').innerHTML = `<div class="box">${image}</div>`;
//actual code
setTimeout(() => {
let height;
let imageWidth;
function calculateHeightAndWidth() {
height = window.getComputedStyle(document.querySelector('.box'), null).getPropertyValue('height');
imageWidth = window.getComputedStyle(document.querySelector('.box img'), null).getPropertyValue('width');
}
calculateHeightAndWidth()
console.log('height',height,'width',imageWidth);
wrapImage = `<div class="select" style="width:calc(${imageWidth} + 10px);height:${height};position:absolute;left:0;top:0;border:1px solid yellow;"></div>`;
document.querySelector('.box').insertAdjacentHTML('beforeend',wrapImage);
document.querySelector('.select').height = document.querySelector('.select').height + 10;
calculateHeightAndWidth()
console.log('after computed height and added 10px',window.getComputedStyle(document.querySelector('.box'), null).getPropertyValue('height'));
},700);
.box{
width:100%;
height:auto;
border:1px solid red;
position:relative;
}
<div id="content">
</div>
I see that you are creating your imgNode on a fly using ternary which means you do not have it pre-created in your HTML. So for that, you can use the solution as below by creating an Image constructor.
const images = [
"https://via.placeholder.com/150",
"https://via.placeholder.com/110/0000FF/808080%20?Text=Digital.com",
"https://via.placeholder.com/80/0000FF/808080%20?Text=Digital.com"
];
const img = new Image();
img.addEventListener("load", (ev) => {
console.log(ev);
document.getElementById(
"content"
).innerHTML = `<div class="box">${ev.target}</div>`;
const height = window
.getComputedStyle(document.querySelector(".box"), null)
.getPropertyValue("height");
const imageWidth = window
.getComputedStyle(document.querySelector(".box img"), null)
.getPropertyValue("width");
console.log("height", height, "width", imageWidth);
const wrapImage = `<div style="width:calc(${imageWidth} + 10px);height:calc(${height} + 10px);position:absolute;left:0;top:0;border:1px solid yellow;"></div>`;
document.querySelector(".box").insertAdjacentHTML("beforeend", wrapImage);
});
img.src = `${images[Math.floor(Math.random() * images.length)]}`;
I want to generate five image imgs first in left side, then remove the lastchild of it and copy the rest to the right side. If user clicks the extra img in left side, then clear all and generate more 5(10) img in left and copy 9 to the right side, and so on. If user clicks the wrong place, alert ("game over").Here is my code:
<html>
<head>
<style>
img{
position: absolute;
}
div{
position: absolute;
width: 500px;
height: 500px;
}
#rightSide { left: 500px;
border-left: 1px solid black;
}
</style>
<script>
var numberOfFaces = 5;
function generateFaces(){
var theLeftSide = document.getElementById("leftSide");
for (var i = 0; i < numberOfFaces; i++){
var img = document.createElement("img");
img.src = "smile.png";
var randomTop = Math.random() * 400;
var randomLeft = Math.random() * 400;
img.style.top = randomTop + "px";
img.style.left = randomLeft + "px";
theLeftSide.appendChild(img);
}
var theRightSide = document.getElementById("rightSide");
leftSideImages = theLeftSide.cloneNode(true);
leftSideImages.removeChild(leftSideImages.lastChild);
document.getElementById("rightSide").appendChild(leftSideImages);
var theBody = document.getElementByTagName("body")[0];
theLeftSide.lastChild.onclick = function nextLevel(event){
event.stopPropagation();
while (theBody.firstChild){
theBody.removeChild(theBody.firstChild);
}
numberOfFaces += 5;
generateFaces();
}
theBody.onclick = function gameover(){
alert("Game Over");
thBody.onclick = null;
theLeftSide.lastChild.onclick = null;
}
}
window.onload = generateFaces;
</script>
</head>
<body>
<h1>Matching Game</h1>
<p>click on the extra smiling face on the left</p>
<div id = "leftSide">
</div>
<div id = "rightSide">
</div>
</body>
</html>
I could generate and clone at first time, but when I click, nothing happens, so what is the problem?
This may be a typing error.
var theBody = document.getElementsByTagName("body")[0];
your code: var theBody = document.getElementByTagName("body")[0];
I suggest to use a good editor for html. I fixed the error with Jetbrain phpStorm but better ones may exist.
Bellow is a modified version that worked for me. Notice that in this version I added the events on all children instead of the whole document body. I don't know but for me it feels more accurate not to end the game on a user clicks on a white space for example.
<html>
<head>
<style>
img{
position: absolute;
}
div{
position: absolute;
width: 500px;
height: 500px;
}
#rightSide { left: 500px;
border-left: 1px solid black;
}
</style>
<script>
var numberOfFaces = 5;
var theBody;
var theLeftSide;
var theRightSide;
function generateFaces(){
theBody = document.getElementsByTagName("body")[0];
theLeftSide = document.getElementById("leftSide");
theRightSide = document.getElementById("rightSide");
for (var i = 0; i < numberOfFaces; i++){
var img = document.createElement("img");
img.src = "smile.png";
var randomTop = Math.random() * 400;
var randomLeft = Math.random() * 400;
img.style.top = randomTop + "px";
img.style.left = randomLeft + "px";
if(theLeftSide != null)
theLeftSide.appendChild(img);
else
{
alert("Game Over");
return;
}
}
var leftSideImages = theLeftSide.cloneNode(true);
leftSideImages.removeChild(leftSideImages.lastChild);
document.getElementById("rightSide").appendChild(leftSideImages);
addEvents();
}
function addEvents(){
for(var i=0; i < theLeftSide.childNodes.length; i++){
theLeftSide.childNodes[i].onclick = nextLevel;
}
}
function removeEvents(){
for(var i=0; i < theLeftSide.childNodes.length; i++){
theLeftSide.childNodes[i].onclick = null;
}
}
function nextLevel(event){
if(this == theLeftSide.lastChild){
event.stopPropagation();
theLeftSide.innerHTML = "";
theRightSide.innerHTML = "";
numberOfFaces += 5;
generateFaces();
}
else
{
alert("Game Over");
removeEvents();
}
}
window.onload = generateFaces;
</script>
</head>
<body>
<h1>Matching Game</h1>
<p>click on the extra smiling face on the left</p>
<div id = "leftSide">
</div>
<div id = "rightSide">
</div>
</body>
</html>
I've tried all sorts of things to figure out why my code isn't however, I can't seem to find out why. `
var numberOfFaces = 5;
var theleftside = document.getElementById ("leftSide");
var top_position = Math.floor((Math.random() * 400) + 1);
var left_position = Math.floor((Math.random() * 400) + 1);
var theRightSide = document.getElementById("rightSide");
function generatefaces () {
for (var i = 1; i < numberOfFaces; i++) {
var img = document.createElement("img");
img.src = "smile.png";
img.style.top = top_position + "px";
img.style.left = left_position + "px";
theleftside.appendChild(img);
}
}
<style media="screen">
img {
position: absolute;
}
div {
position: absolute;
width: 500px;
height: 500px;
}
#rightSide {
left: 500px;
border-left: 2px solid black;
}
</style>
<h1>The Matching Game</h1>
<p>Click on the extra smiling face on the left.</p>
<div id="leftSide">
</div>
<div id="rightSide">
</div>
`
I am trying to generate 5 images (smiley faces) on the lefside div at different positions, then trying to clone it to the right hand side,
I'm new with JS, so hints and tips would be much appreciated.
Because you just implemented a function but did not call it. Try adding
generatefaces();
at the end.
Two fold firstly you need to, as burkay says, call the function generatefaces().
Secondly you need to create a second element for the right side using img.cloneNode(true) this creates a duplicate so you can then append that to the right side.
Also you are generating the random position outside of the loop so the same random position is used for each img you instead need to create a random position for every img by moving it inside the loop.
Example:
var numberOfFaces = 5;
var theleftside = document.getElementById("leftSide");
var theRightSide = document.getElementById("rightSide");
// You need to call this function
generatefaces()
function generatefaces() {
for (var i = 1; i < numberOfFaces; i++) {
// Generate the new random position for each img
var top_position = Math.floor((Math.random() * 400) + 1);
var left_position = Math.floor((Math.random() * 400) + 1);
var img = document.createElement("img");
// The location of your face image
img.src = "https://upload.wikimedia.org/wikipedia/commons/thumb/5/54/Emojione_1F60E.svg/64px-Emojione_1F60E.svg.png";
img.style.top = top_position + "px";
img.style.left = left_position + "px";
// Creates a duplicate version of the image
var imgright = img.cloneNode(true);
theleftside.appendChild(img);
// Appends the duplicate image to the right side
theRightSide.appendChild(imgright);
}
}
img {
position: absolute;
}
div {
position: absolute;
width: 500px;
height: 500px;
}
#rightSide {
left: 500px;
border-left: 2px solid black;
}
<h1>The Matching Game</h1>
<p>Click on the extra smiling face on the left.</p>
<div id="leftSide">
</div>
<div id="rightSide">
</div>
Hope this helps!
The code is supposed to generate 5 elements one by one so that when the page is downloaded all we`ll see 5 elements (newFace) in random places.
This code generates all 5 elements but they are staying aligned one by one instead of appearing in random position as wished
function generate_faces() {
var theLeftSide = document.getElementById("leftSide");
var number_of_faces = 0;
while (number_of_faces < 5){
var top_position = Math.floor(Math.random()*300);
var left_position = Math.floor(Math.random()*300);
newFace = document.createElement("img");
newFace.setAttribute(
"src",
"http://home.cse.ust.hk/~rossiter/mooc/matching_game/smile.png"
);
newFace.style.top = top_position+"px";
newFace.style.left = left_position+"px";
theLeftSide.appendChild(newFace);
number_of_faces = number_of_faces + 1;
}
}
Try this.
<!DOCTYPE html>
<html>
<head></head>
<style>
html, body, leftSide {
width: 100%;
height: 100%;
position: relative;
}
#leftSide {
position: relative;
}
#leftSide img {
position: absolute;
}
</style>
<body onclick="generate_faces()">
<div id="leftSide">
</div>
</body>
</html>
<script>
function generate_faces() {
var theLeftSide = document.getElementById("leftSide");
var number_of_faces = 0;
while (number_of_faces < 5){
var top_position = Math.floor(Math.random()*300);
var left_position = Math.floor(Math.random()*300);
newFace = document.createElement("img");
newFace.setAttribute(
"src",
"http://home.cse.ust.hk/~rossiter/mooc/matching_game/smile.png"
);
newFace.style.top = top_position+"px";
newFace.style.left = left_position+"px";
theLeftSide.appendChild(newFace);
number_of_faces = number_of_faces + 1;
}
}
</script>
I want to clone the images of the div leftSide into the div rightSide. On each click on the body the images on the left div should be cloned into the right div. But I can't get the result with the code I'm doing. Is there any mistake in my code? I want to use JavaScript.
Here's my code:
var theLeftSide = document.getElementById("leftSide");
var width = 500; var height = 500;
top_position = 0; var left_position = 0,
var numberOfFaces = 5;
var theRightSide = document.getElementById("rightSide");
var leftSideImages = theLeftSide.cloneNode(true);
document.getElementById("rightSide").appendChild(leftSideImages);
for (var i = 0; i < 5; i++) {
createElement(i);
numberOfFaces += 5;
function createElement() {
var image = document.createElement('img');
image.src = "smile.png";
image.style.position = 'absolute';
image.style.top = top_position + "px";
image.style.left = left_position + "px";
theLeftSide.appendChild(image);
top_position = Math.random() * 500 ;
left_position = Math.random() * 500 ;
Here is a simple example that clones an HTMLElement in vanilla javascript:
additional information can be found in MDN
function CloneCtrl() {
'use strict';
var self = this;
self.source = document.querySelector('.source');
self.target = document.querySelector('.target');
self.cloneSource = function(event) {
var clone = self.source.cloneNode(true);
self.target.appendChild(clone);
}
document
.getElementById('cloneBtn')
.addEventListener('click', self.cloneSource)
;
}
document.addEventListener('DOMContentLoaded', CloneCtrl);
.source {
background: lightseagreen;
width: 100px;
height: 100px;
line-height: 100px;
overflow: hidden;
margin: 5px;
display: inline-block;
text-align: center;
color: #fff;
}
.target {
border: 1px solid lightcoral;
min-height: 110px;
}
<div><button id="cloneBtn">Clone Source</button></div>
<div class="source">SOURCE</div>
<hr>
<div class="target"></div>
With jQuery, you can do it kike that:
$('#div2').html($('#div1').html());
which is found from this question: Copy the content of a div into another div.
You don't actually provide many details, thus the best I can post, hope it helps!!
you could simply try this if you have second div on page.
document.getElementById("SecondDv").innerHTML = document.getElementById("FirstDv").innerHTML;
This will copy whatever is there in FirstDiv to Second. lmk if it works.