Adding multiple images with preview - javascript

I have multiple images that need to be uploaded and in preview user should be able to select one of those images for their main image.My idea was to assign them an id with counted but that doesn't seem to work,they always have the same id of number of images that are uploaded. This is js a code that I am using
$(function() {
var imagesPreview = function(input, placeToInsertImagePreview) {
if (input.files) {
var filesAmount = input.files.length;
for (i = 0; i < filesAmount; i++) {
var reader = new FileReader();
reader.onload = function(event) {
$($.parseHTML("<img height=' 50px' width='50px' class='img-id' id='" +i+"'>")).attr('src', event.target.result).appendTo(placeToInsertImagePreview);
}
reader.readAsDataURL(input.files[i]);
}
}
};
$('#gallery-photo-add').on('change', function() {
imagesPreview(this, 'div.gallery');
});
});

I think the problem here is because you declared i as a global variable, so when the onload method is called it is getting the i global value which is now equal to your array size.
Fix by declaring the var properly.
$(function() {
var imagesPreview = function(input, placeToInsertImagePreview) {
if (input.files) {
var filesAmount = input.files.length;
for (var i = 0; i < filesAmount; i++) {
let index = i;
var reader = new FileReader();
reader.onload = function(event) {
$($.parseHTML("<img height=' 50px' width='50px' class='img-id' id='" + index + "'>"))
.attr('src', event.target.result)
.appendTo(placeToInsertImagePreview);
}
reader.readAsDataURL(input.files[i]);
}
}
};
$('#gallery-photo-add').on('change', function() {
imagesPreview(this, 'div.gallery');
});
});

Related

Importing data to localstorage

Could anybody help me out sorting the following code or help me in the right direction?
It needs to import data from a .txt file and store it into localstorage as key & value.
Key is before ':' and value comes after it. A new key / value is separated after each ','.
Sample data from .txt file is:
nl-step1chapter1Question6:U2FsdGVkX19bRT84xShxK+29ypgj1d6ZHt+2DVBCUtY=,nl-step1chapter1Question1:U2FsdGVkX1+/Sv61L69bLvQGTkf1A9Uy4jgJ3KZTkzI=,nl-step1chapter1Question4:U2FsdGVkX1+9SVVOvTKeZuaQGj58L5WnEgL8htS0c7U=,jft:320982da-f32a-46a2-a97c-605ebe305518,nl-step1chapter1Question5:U2FsdGVkX19pi8A+PQZ7rBNCWrFeCwl2HdXpV+wWkFk=,nl-step1chapter1Question2:U2FsdGVkX19hnRnpmP3omzYNU0jXd3NtsHM+mvGYBnc=,nl-step1chapter1Question3:U2FsdGVkX1+hPbMRN+x19y7pF73eXoxG0qK1igZYZbA=
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script>
<script type="application/x-javascript">
$(function importData() {
document.getElementById('file').onchange = function () {
//debugger;
var file = this.files[0];
var reader = new FileReader();
reader.onload = function (progressEvent) {
//console.log(this.result.split(','));
var lines = this.result.split(',');
var list = [];
for (var line = 0; line < lines.length; line++) {
list.push(lines[line]);
localStorage.setItem([line],lines);
}
};
reader.readAsText(file);
};
});
</script>
Any help is much appreciated!
The way you are using FileReader doesn't seem correct to me. This is how your importData() function should be:
$(function importData() {
document.getElementById('file').onchange = function (event) {
var input = event.target;
var reader = new FileReader();
reader.onload = function () {
var text = reader.result;
var lines = text.split(',');
for (var line = 0; line < lines.length; line++) {
let elements = lines[line].split(':');
localStorage.setItem(elements[0], elements[1]);
}
};
reader.readAsText(input.files[0]);
};
});
It will insert the elements in the localStorage as you described. For example: key = step1chapter1Question1 and value = U2FsdGVkX1+/Sv61L69bLvQGTkf1A9Uy4jgJ3KZTkzI=

Show mulitple images after event change using jquery

I have a mulitple input file and I will want to display the selected images in a div.
I tried with this code but it just shows me the first image
I try with this :
function readURL(input) {
var reader = new FileReader();
reader.onload = function(e) {
for (var i = 0; i <= input.files.length; i++) {
var imgId = $('<img />', {
id: 'show_bultin_paie-' + input.files[i].lastModified,
alt: 'MyAlt'
});
imgId.appendTo($('#imagediv'));
$(imgId).attr('src', e.target.result);
}
}
reader.readAsDataURL(input.files[0]);
}
}
$('#file_test').change(function(event) {
readURL(this);
});
You're not looping all the files, you're only reading the first one (reader.readAsDataURL(input.files[0]);). Use let instead of var since you're doing async stuff inside the loop.
function readURL(input) {
for (let i = 0; i < input.files.length; i++) {
var reader = new FileReader();
reader.onload = function(e) {
$('#imagediv').append("<img src='"+e.target.result+"'>");
}
reader.readAsDataURL(input.files[i]);
}
}
$('#file_test').change(function(event) {
readURL(this);
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type=file id=file_test multiple accept='image/png, image/jpg, .png, .jpg'>
<div id=imagediv></div>

How to load image from directory, then show onclick

I am trying to have a function which has functions that do the following.
One function to store the files i get with input into the parent functions loadedimages array(loadimages).
One function to show those files in the correct component(showLoadedImages).
And one function to make the correct img file appear on the correct component.
The last function is what i want it to be like(it does not work).
The other two seem ok.
The problem i have is how to make the last function work while using the loadedimages array. You can change what i store in the array , i wouldnt mind.
Here is the JS code:
function imgviewer() {
"use strict";
var loadedimages = [];
var lidivs = [];
function loadimages() {
var files = document.getElementById("images").files;
for (var i = 0; i < files.length; i++) {
var file = files[i];
if (!file.name.match(/\.(jpg|jpeg|png|gif)$/)) {
alert('THERE IS NO IMAGE IN THIS DIRECTORY.');
break;
}
loadedimages.push(file);
}
}
function showLoadedImages(elem) {
loadimages();
var ld = loadedimages;
//var files = getLoadedImages(); //filelist obj
for (var i = 0; i < ld.length; i++) {
var file = ld[i];
var reader = new FileReader();
reader.onload = (function(file) {
return function(e) {
// Render thumbnail.
var span = document.createElement(
'span');
span.innerHTML = [
'<img class="tile" src="',
e.target.result,
'" title="', encodeURI(
file.name), '">'
].join('');
document.getElementById(elem).insertBefore(
span, null);
lidivs.push(span);
};
})(file);
// Read in the image file as a data URL.
reader.readAsDataURL(file);
}
}
function showImage(index, elem) {
var chosenFile = loadedimages[index];
document.getElementById(elem).src = chosenFile;
}
document.getElementById('images').addEventListener('change', function(){
showLoadedImages("main");
}, false);
}
And some HTML
<form name="uploadForm">
<input id="images" type="file" webkitdirectory mozdirectory directory name="myFiles"
multiple/>
<span id="list"></span>
</form>
<div id="sidebar1"><img id="willchange" src="images/railaythailand.jpg" width="1200" height="832" alt=""/></div>
<div id="main"></div>
When i call showLoadedImages("main") the images are shown in main div. I want to be able to click those images so that they appear on "willchange" .
This does what you asked for. There are a number of other issues with your code that you might want to address, starting with the images are not thumbnails at all (and shrunken images take just as long to load as the original), but perhaps I'm missing something.
"use strict";
var loadedimages = [];
var lidivs = [];
function loadimages() {
var files = document.getElementById("images").files;
for (var i = 0; i < files.length; i++) {
var file = files[i];
if (!file.name.match(/\.(jpg|jpeg|png|gif)$/)) {
continue;
}
loadedimages.push(file);
}
loadedimages.length || alert('THERE IS NO IMAGE IN THIS DIRECTORY.');
}
function showLoadedImages(elem) {
loadimages();
var ld = loadedimages;
//var files = getLoadedImages(); //filelist obj
for (var i = 0; i < ld.length; i++) {
var file = ld[i];
var reader = new FileReader();
reader.onload = (function(file) {
return function(e) {
// Render thumbnail.
var span = document.createElement(
'span');
span.innerHTML = [
'<img data-index="',
lidivs.length,
'" class="tile" src="',
e.target.result,
'" title="', encodeURI(
file.name), '">'
].join('');
span.addEventListener("click", foo );
document.getElementById(elem).insertBefore(
span, null);
lidivs.push(span);
};
})(file);
// Read in the image file as a data URL.
reader.readAsDataURL(file);
}
}
function showImage(index, elem) {
document.getElementById(elem).src = lidivs[index].children[0].src;
}
function foo(event) {
showImage(event.target.dataset.index, "willchange");
}
function show() {
showLoadedImages("list");
}
function init() {
document.getElementById("images").addEventListener("change", show, false);
}
document.addEventListener( "DOMContentLoaded", init, false );
<body>
<form name="uploadForm">
<input id="images" type="file" webkitdirectory mozdirectory directory name="myFiles"
multiple/>
<span id="list"></span>
</form>
<div id="sidebar1"><img id="willchange" src="images/railaythailand.jpg" width="1200" height="832" alt=""/></div>
</body>

How to Change the Source of an Image W/JS

I have to change the src of an image using java script and I am pretty sure i hit a road block, in the html I have 3 li elements and in the id is the source of the mouseenter img. I feel like I am close but so far. Heres my code so far. Thanks for any help!
Javascript:
var $ = function (id) {
return document.getElementById(id);};
window.onload = function () {
var links = document.getElementsByTagName("li"),
imgElements = document.getElementsByTagName("img"),
imgNode,
i,
URLone,
URLtwo,
link,
image;
for (i = 0; i < imgElements.length; i++) {
imgNode = imgElements[i];
}
imgNode.mouseenter = function () {
var img = this;
URLtwo = img.getAttribute('id');
img.src = URLtwo;
}
imgNode.mouseout = function () {
var img = this;
URLone = img.getAttribute('src');
img.src = URLone;
};
//preload
for (i = 0; i < links.length * 2; i++) {
link = links[i];
image = new Image();
image.src = link.src;
image = new Image();
image.src = link.id;
}};
HTML ::
<body>
<section>
<h1>Ram Tap Combined Test</h1>
<ul id="image_rollovers">
<li><img src="images/h1.jpg" alt="" id="images/h4.jpg"></li>
<li><img src="images/h2.jpg" alt="" id="images/h5.jpg"></li>
<li><img src="images/h3.jpg" alt="" id="images/h6.jpg"></li>
</ul>
</section>
Working jQuery :
$(document).ready(function() {
$("#image_rollovers img").each(function() {
var oldURL = $(this).attr("src"); // gets the src attribute
var newURL = $(this).attr("id"); // gets the id attribute
// preload images
var rolloverImage = new Image();
rolloverImage.src = newURL;
$(this).hover(
function() {
$(this).attr("src", newURL); // sets the src attribute
},
function() {
$(this).attr("src", oldURL); // sets the src attribute
}
); // end hover
}); // end each
}); // end ready
for (i = 0; i < imgElements.length; i++) {
(function(imgNode) {
imgNode.addEventListener("mouseenter", function () {
var img = this;
URLtwo = img.getAttribute('id');
img.src = URLtwo;
}, false);
imgNode.addEventListener("mouseout", function () {
var img = this;
URLone = img.getAttribute('src');
img.src = URLone;
}, false);
})(imgElements[i]);
}
A couple of problems in your code.
First for loop closing right away, instead should close after your
imgNode.mouseout function
for (i = 0; i < imgElements.length; i++) {
imgNode = imgElements[i];
imgNode.mouseenter = function () {
var img = this;
URLtwo = img.getAttribute('id');
img.src = URLtwo;
}
imgNode.mouseout = function () {
var img = this;
URLone = img.getAttribute('src');
img.src = URLone;
};
}
//preload
for (i = 0; i < links.length * 2; i++) {
link = links[i];
image = new Image();
image.src = link.src;
image = new Image();
image.src = link.id;
}};
Last for loop runs 6 times but there are only 3 tags in html. When it coming to loop no. 3 it doesn't get any value for link.src.
Also links variable provides a collection of 'li' tags and not 'img', last for loop requires src from link.src which doesn't have any value, need to change
var links = document.getElementsByTagName("li"),
to
var links = document.getElementsByTagName("img"),
Try that. Hopefully after correcting above errors your code should work.

Variable isn't increementing on file reader

I'm trying to do thumbnails for the images uploaded. I want to create diferents classes for the thumbs, for this, I'm trying to use de i of the loop. But this assume just the final value. Why? Thanks
for (var i = 0; i < inp.files.length; i++) {
//create the thumbnails
var reader = new FileReader();
reader.onload = function (e) {
$('.thumbs').append('<div class="thumb_item" id="c'+ i +'"></div>');
$('<img />').attr({'src': e.target.result}).addClass('img_thumb').appendTo('.thumb_item:last');
};
reader.readAsDataURL(this.files[i]);
}
Why can't you apply the same technique pointed out in the comment?
reader.onload = (function(index)
{
return function (e)
{
$('.thumbs').append('<div class="thumb_item" id="c'+ index +'"></div>');
$('<img />').attr({'src': e.target.result}).addClass('img_thumb').appendTo('.thumb_item:last');
};
})(i);
Thanks for all, I solved this way:
for (var i = 0; i < inp.files.length; i++) {
var reader = new FileReader();
// Closure to capture the file information.
reader.onload = (function (theFile) {
var count = i;
return function (e) {
$('.thumbs').append('<div class="thumb_item" id="c'+ count +'"></div>');
$('<img />').attr({'src': e.target.result}).addClass('img_thumb').appendTo('.thumb_item:last');
};
})(i);
reader.readAsDataURL(this.files[i]);
}

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