I want display image preview on change event of file input. So I am creating Image element using JavaScript and I want to wrap it inside a div to display a close button. To achieve this I have written following code:
preview(event, imageList) {
let imgLen = event.target.files.length;
if (imgLen > 0) {
for (let i = 0; i < imgLen; i++) {
let myImage = new Image(100, 100);
myImage.src = URL.createObjectURL(event.target.files[i]);
myImage.setAttribute('style', 'margin: 5px');
imageList.appendChild("<div>" + myImage + "</div>");
}
}
}
But I throwing error at the run time.
error
Use this:
var divNode = document.createElement('DIV');
divNode.appendChild(myImage);
imageList.appendChild(divNode);
preview(event, imageList) {
let imgLen =event.target.files.length;
if(imgLen > 0) {
for (let i = 0; i< imgLen; i++) {
let myImage = new Image(100, 100);
myImage.src = URL.createObjectURL(event.target.files[i]);
let div = document.createElement('div');
div.appendChild(myImage);
myImage.setAttribute('style', 'margin: 5px');
imageList.append( myImage);
}
}
Related
I'm new to javascript and I need some help with a function that I am trying to get to run. I would like for the background of my body to change every seconds using the images provided but when I try to run the script it does not seem to work.
Javascript:
var i = 0;
var images = [
URL('file:///Users/BodyDesigns/Documents/Altered%20Images/P1010216.jpg'),
URL('file:///Users/BodyDesigns/Documents/Altered%20Images/P1010217.jpg'),
URL('file:///Users/BodyDesigns/Documents/Altered%20Images/P1010200.jpg')
];
function backgroundChanger() {
for(; i < images.length; i++) {
document.getElementById('background').style.backgroundImage.innerHTML = images[i];
}
}
setInterval( backgroundChanger(), 4000);
html:
<body id="background" onLoad="backgroundChanger()">
This should do the trick.
var i = 0;
var images = [
'https://upload.wikimedia.org/wikipedia/commons/2/23/Screenshot_from_IMAX%C2%AE_3D_movie_Hidden_Universe_showing_the_Helix_Nebula_in_infrared.jpg',
'http://ichef.bbci.co.uk/wwfeatures/wm/live/1280_640/images/live/p0/40/m0/p040m0bc.jpg',
'http://az616578.vo.msecnd.net/files/2016/08/06/636060577940287734-194579614_maxresdefault.jpg'
];
function backgroundChanger() {
if(i >= images.length){
i = 0;
}
document.getElementById('background').style.backgroundImage = 'url(' + images[i++] + ')';
}
setInterval( backgroundChanger, 4000);
As you can see, the url() should be passed inside a string to work. And there is no innerHtml on backgroundImage property.
I am not sure how to use increments.
through a function. i can't get the paragraph to show the array words
<p id= "demo"
var Array = ["hello", "goodbye"];
var mimg = document.getElementById(imageArray[0]);
mimg.setAttribute('src', [index]);
//var ArrayIndex = 0;
function change() {
("src", Array[Index]);
imageIndex++;
if (Index >= Array.length) {
Index = 0;
}
}
Don't forget to use your browser's console, read this article Using Your Browser to Diagnose JavaScript Errors.
Don't use setattribute function, use src attribute.
var myImage = document.getElementById("mainImage");
var imageArray = ["http://lorempixel.com/400/200/sports/1/", "http://lorempixel.com/400/200/sports/2/", "http://lorempixel.com/400/200/sports/3/", "http://lorempixel.com/400/200/sports/4/"];
myImage.src = imageArray[0];
var imageIndex = 0;
function changeImage() {
myImage.src = imageArray[imageIndex];
imageIndex++;
if (imageIndex >= imageArray.length)
imageIndex = 0;
}
window.onload = function() {
setInterval(function() {
changeImage();
}, 1000);
};
<img id="mainImage" />
var myImage = document.getElementById("mainImage");
var imageArray = ["images/1.png","images/2.png","images/3.png","images/4.png"];
var mimg=document.getElementById(imageArray[0]);
mimg.setAttribute('src',photos[index]);
You aren't showing your relevant HTML, but I notice in this section you are getting an element with ID "images/1.png" and setting the src of that element to the value of something in photos[index]. You haven't shown how the photos array is loaded. Do you actually have an element with an ID "images/1.png"?
In your function, you set the src of the mainImage to the values in imageArray rather than the values in the photo array. That may be valid, but since that is different than what you did outside the function, I want to make sure that was intended.
I think you are talking about such solution:
var imageArr=["images/1.png", "images/2.png", "images/3.png", "images/4.png"];
$('#button'). on('click',function(){
var index=(Math.random(0,imageArr.length)*10)
$('#img').attr('src',imageArr[index])
});
Again you question is not clear, thus I think this will help you to get direction.
This should be solution if you are using plain JavaScript
var myImage = document.getElementById("mainImage"),
imageArray = ["images/1.png", "images/2.png", "images/3.png", "images/4.png"],
imageArrayIndex = 0;
myImage.src = imageArray[imageArrayIndex++];
function changeImage () {
myImage.src = imageArray[imageArrayIndex++];
imageArrayIndex = imageArrayIndex >= imageArray.length ? 0 : imageArrayIndex;
}
Make sure that your element is defined as "img".
Here's a solution which sets a data-index attribute on the image to keep track of the selected index. This solution is compatible with down to IE8 and does not use the Jquery library. Run the code snippet below for a test (click the image to go to the next one).
var mimg = document.getElementById('main-image'),
simg = document.getElementById('sec-image')
imgArr = [
'http://placehold.it/50x50/00AAAA',
'http://placehold.it/50x50/AAAA00',
'http://placehold.it/50x50/AA00AA',
];
var loopImages = function(element, imgArray, startAt) {
var index = element.getAttribute('data-index'),
newIndex = 0;
if (!index)
newIndex = ((startAt && startAt < imgArr.length-1) || 0) + 1;
else if (index < imgArr.length-1)
newIndex = parseInt(index) + 1;
element.setAttribute('data-index', newIndex);
element.src = imgArr[newIndex];
};
mimg.addEventListener('click', function(e) {
loopImages(e.target || e.srcElement, imgArr);
});
setInterval(function() {
loopImages(simg, imgArr);
}, 500);
<p>Preview (click to change)</p>
<img id="main-image" src="http://placehold.it/50x50/00AAAA">
<br>
<p>Preview with interval</p>
<img id="sec-image" src="http://placehold.it/50x50/00AAAA">
I'm creating an image that changes on click. My code isn't working whats wrong with it?
<div id="img"></div>
<script>
var fNames = ["SD1", "SD2", "SD3", "SD4"]; //File names
var _img = document.getElementById("img"); //Grabs images, groups them
var imgIdx = 0;
_img.style.position = "relative";
_img.style.left = "auto";
_img.style.right = "auto";
_img.style.width = "1920";
_img.style.height = "1280";
_img.style.backgroundImage = "url('images/"+fNames[imgIdx]+".jpg')"; //Retrieves images from file
_img.addEventListener("click", onImageClick); //Allows image click
function onImageClick() {
imgIdx++;
if(imgIdx == 6) {
imgIdx = 0;
}
_img.style.backgroundImage = "url('images/"+fNames[imgIdx]+".jpg')";
}
</script>
You need a unit when you specify the size:
_img.style.width = "1920px";
_img.style.height = "1280px";
When making the index wrap around you are using 6, but it should be 5. Better yet, use the length of the array, that way you don't need to change that part of the code if the array changes:
if(imgIdx > fNames.length) {
imgIdx = 0;
}
Im trying to make a div expanded once you click on another div. In my case I'm try to make div with some text in it expand when the image is clicked. A link to my JSFiddle - https://jsfiddle.net/txoyuvqn/3/
My javascript that I am using looks like.
var divs = document.getElementsByClassName('image');
var whattochange = document.getElementsByClassName('text');
for (var i = 0; i < divs.length; i++)
divs[i].addEventListener("click", function () {
for (var i = 0; i < whattochange.length; i++) {
whattochange[i].style.width = '500px'
whattochange[i].style.transition = 'all 1s'
whattochange[i].style.backgroundColor = 'red'
}
}, false);
However when I click on the class called image it effects all the Text classes, i know it's because were changing the css to all of the text divs, however is there a way to make it only effect the correlating div? Or am I going about creating this in the wrong way?
getElementsByClassName returns an array, not a single element.
divs is an array, and you are correctly using a for loop and the index indicator [i] after your variable name divs.
You need a similar for loop for whattochange.
var divs = document.getElementsByClassName('image');
var whattochange = document.getElementsByClassName('text');
for (var i = 0; i < divs.length; i++)
divs[i].addEventListener("click", function () {
for (var i = 0; i < whattochange.length; i++) {
whattochange[i].style.width = '800px';
whattochange[i].style.transition = 'all 1s';
whattochange[i].style.backgroundColor = 'red';
}
}, false);
There may be a better way, but you could do it like this:
var divs = document.getElementsByClassName('image');
var whattochange = document.getElementsByClassName('text');
for (var i = 0; i < divs.length; i++)
{
divs[i].addEventListener("click", function()
{
var w = document.getElementById(this.id.replace('img', 'text'));
w.style.width = '800px'
w.style.transition = 'all 1s'
w.style.backgroundColor = 'red'
});
whattochange[i].id = 'text' + i;
divs[i].id = 'img' + i;
}
See the fiddle
Javascript
var divs = document.getElementsByClassName('image');
var whattochange = document.getElementsByClassName('text');
for (var i = 0; i < divs.length; i++) {
divs[i].addEventListener("click", function () {
for (var i = 0; i < whattochange.length; i++) {
whattochange[i].style.width = '800px';
whattochange[i].style.transition = 'all 1s';
whattochange[i].style.backgroundColor = 'red';
}
}, false);
}
You have to be sure that the elements exist if your JavaScript code depends on them. The reason why your fiddle didnt work was because, you was not loading the script after the body has finished loading.
In your code, One way of achieving this is by putting the <script> tag at the end of the body like this:
<html>
<head></head>
<body>
<script type="text/javascript">
// code here
</script>
</body>
You can also put all your code in a function for the window.onload event or use jQuery.
I want to analyse every image of an article and set an class for all images smaller/equal than perhaps 400px (and another class for images bigger than 400px) so that I can give them a specific style.
In jQuery it would be perhaps something like this
$('div#content').find('img').each(function () {
var $this = $(this), width = $this.width();
if (width <= 400) {
$this.addClass('small_img');
}
var $this = $(this), width = $this.width();
if (width > 400) {
$this.addClass('large_img');
}
});
But I need it to be in pure Javascript. As a stupid Journalist and Webdesigner I don't get it... If you could help me, I would be very thankful.
You mean something FAST and short like this?
window.onload = function() {
var n=document.getElementById('content').getElementsByTagName('img'),
i=n.length;
while(i--){
n[i].className = n[i].clientWidth > 400 ? 'large_img' : 'small_img' ;
}
};
See this fiddle for working example.
Also read this question on SO for selecting a method to fetch the (computed) width.
window.onload = function() {
var content = document.getElementById('content');
if (content) {
var img = content.getElementsByTagName('img');
for (var i = 0, count = img.length; i < count; i++) {
if (img[i].offsetWidth <= 400) {
img[i].className += ' small_img';
} else {
img[i].className += ' large_img';
}
}
}
};
Something like this should work:
// Find the parent container 'div#content'
var container = document.getElementById( "content" ),
// Find all images within the parent
images = container.getElementsByTagName( "img" ),
// Total number of images to check
len = images.length,
// Loop counter
i = 0,
// Represents the current image in the loop
image;
// Loop through all the images
for ( ; i < len; i++ ) {
// Access the current image
image = images[ i ];
// Use the ternary operator to assign one of two classes, based on width
image.className += ( image.clientWidth > 400 ) ? " large_img" : " small_img";
}
Hope that helps. Cheers!
var contentDiv = document.getElementById('content');
var imgs = contentDiv.getElementsByTagName('img');
for(i=0;i<img.length;i++){
var img = imgs[i];
if(img.clientWidth <= 400) img.className += " small_img"
else img.className += " large_img"
}