Currently, I'm developing a drag and drop feature. The problem is that I can't figure out how to get multiple files from user separately. Let's say that we have a drop zone container and when user drops there images, it assigns them to <input type="file">. Let's say, a user drops here an image and then decides to drop another image and we have to somehow add this second image to the input. I tried finding solution in the Internet(of course :)) but found nothing that solves this problem.
Here is my HTML:
<form action="" method="POST" enctype="multipart/form-data">
<div class="drop_zone">
<span class="drop_zone__prompt">Drop your files here</span>
<input required name="images" type="file" multiple class="drop_zone__input">
</div>
<input type="submit" value="Отправить">
</form>
JavaScript:
document.querySelectorAll('.drop_zone__input').forEach(InputElement => {
const dropZoneElement = InputElement.closest('.drop_zone');
dropZoneElement.addEventListener('drop', e => {
e.preventDefault();
if (e.dataTransfer.files.length){
InputElement.files = e.dataTransfer.files;
}
});
I tried this:
dropZoneElement.addEventListener('drop', e => {
e.preventDefault();
if (e.dataTransfer.files.length){
myfiles = e.dataTransfer.add(InputElement.files);
InputElement.files = myfiles;
}
});
But it returns error saying that 'e.dataTransfer.add is not a function'
Why I tried this:
I found add() method here
And this article says:
The DataTransferItemList object is a list of DataTransferItem objects representing items being dragged. During a drag operation, each DragEvent has a dataTransfer property and that property is a DataTransferItemList.
Actually, there is a way to do that. It's far from straightforward, but it does work.
The only way to create a FileList object is to create a custom DataTransfer object. You can add files to it using dataTransfer.items.add(), and obtain the corresponding FileList through dataTransfer.files.
So, create a new DataTransfer object every time you want to add files, add the existing and the new files to it, and assign its FileList to the files property of the input element.
Note: You can't use the drop event's DataTransfer object for this, because it's read-only.
document.querySelectorAll('.drop_zone__input').forEach(InputElement => {
const dropZoneElement = InputElement.closest('.drop_zone');
dropZoneElement.addEventListener('dragover', e => {
e.preventDefault()
});
dropZoneElement.addEventListener('drop', e => {
e.preventDefault();
//Create a new DataTransfer object
const dataTransfer = new DataTransfer
//Add new files from the event's DataTransfer
for(let i = 0; i < e.dataTransfer.files.length; i++)
dataTransfer.items.add(e.dataTransfer.files[i])
//Add existing files from the input element
for(let i = 0; i < InputElement.files.length; i++)
dataTransfer.items.add(InputElement.files[i])
//Assign the files to the input element
InputElement.files = dataTransfer.files
});
})
.drop_zone{
height: 200px;
width: 200px;
border: solid black 1px;
}
<form action="" method="POST" enctype="multipart/form-data">
<div class="drop_zone">
<span class="drop_zone__prompt">Drop your files here</span>
<input required name="images" type="file" multiple class="drop_zone__input">
</div>
<input type="submit" value="Отправить">
</form>
You can also reuse the same DataTransfer object, so you don't have to re-add the existing files.
However, in this case, you also have to handle input events on the input element.
document.querySelectorAll('.drop_zone__input').forEach(InputElement => {
const dropZoneElement = InputElement.closest('.drop_zone');
const dataTransfer = new DataTransfer
dropZoneElement.addEventListener('dragover', e => {
e.preventDefault()
});
dropZoneElement.addEventListener('drop', e => {
e.preventDefault();
//Add new files from the event's DataTransfer
for(let i = 0; i < e.dataTransfer.files.length; i++)
dataTransfer.items.add(e.dataTransfer.files[i])
//Assign the files to the input element
InputElement.files = dataTransfer.files
});
InputElement.addEventListener('input', e => {
dataTransfer.items.clear()
for(let i = 0; i < InputElement.files.length; i++)
dataTransfer.items.add(InputElement.files[i])
})
})
.drop_zone{
height: 200px;
width: 200px;
border: solid black 1px;
}
<form action="" method="POST" enctype="multipart/form-data">
<div class="drop_zone">
<span class="drop_zone__prompt">Drop your files here</span>
<input required name="images" type="file" multiple class="drop_zone__input">
</div>
<input type="submit" value="Отправить">
</form>
Or, if you want to add the files when interacting with the file input instead of replacing them, you can do this:
document.querySelectorAll('.drop_zone__input').forEach(InputElement => {
const dropZoneElement = InputElement.closest('.drop_zone');
const dataTransfer = new DataTransfer
dropZoneElement.addEventListener('dragover', e => {
e.preventDefault()
});
dropZoneElement.addEventListener('drop', e => {
e.preventDefault();
//Add new files from the event's DataTransfer
for(let i = 0; i < e.dataTransfer.files.length; i++)
dataTransfer.items.add(e.dataTransfer.files[i])
//Assign the files to the input element
InputElement.files = dataTransfer.files
});
InputElement.addEventListener('input', e => {
e.preventDefault()
for(let i = 0; i < InputElement.files.length; i++)
dataTransfer.items.add(InputElement.files[i])
InputElement.files = dataTransfer.files
})
})
.drop_zone{
height: 200px;
width: 200px;
border: solid black 1px;
}
<form action="" method="POST" enctype="multipart/form-data">
<div class="drop_zone">
<span class="drop_zone__prompt">Drop your files here</span>
<input required name="images" type="file" multiple class="drop_zone__input">
</div>
<input type="submit" value="Отправить">
</form>
You can remove files from the DataTransfer object using dataTransfer.items.remove():
document.querySelectorAll('.drop_zone__input').forEach(InputElement => {
const dropZoneElement = InputElement.closest('.drop_zone');
const removeFirstElement = dropZoneElement.querySelector('.drop_zone__remove_first')
const dataTransfer = new DataTransfer
dropZoneElement.addEventListener('dragover', e => {
e.preventDefault()
});
dropZoneElement.addEventListener('drop', e => {
e.preventDefault();
//Add new files from the event's DataTransfer
for(let i = 0; i < e.dataTransfer.files.length; i++)
dataTransfer.items.add(e.dataTransfer.files[i])
//Assign the files to the input element
InputElement.files = dataTransfer.files
});
InputElement.addEventListener('input', e => {
e.preventDefault()
for(let i = 0; i < InputElement.files.length; i++)
dataTransfer.items.add(InputElement.files[i])
InputElement.files = dataTransfer.files
})
removeFirstElement.addEventListener('click', () => {
dataTransfer.items.remove(0)
InputElement.files = dataTransfer.files
})
})
.drop_zone{
height: 200px;
width: 200px;
border: solid black 1px;
}
<form action="" method="POST" enctype="multipart/form-data">
<div class="drop_zone">
<span class="drop_zone__prompt">Drop your files here</span>
<input required name="images" type="file" multiple class="drop_zone__input">
<input type="button" class="drop_zone__remove_first" value="Remove first file">
</div>
<input type="submit" value="Отправить">
</form>
You can't add to the files to the input's list of files, although apparently you can replace that list as described by FZs, which largely comes to the same thing.
Another way to deal with this is to make the original input hidden via CSS and add a new input where it used to be, so it can receive new files. You can make the UI clean by listing all of the files you're going to upload separately from the input.
How you deal with on submission depends on how you're handling submission.
If you're doing a standard HTTP form submission, ensure that your server side script handles all of the files regardless of which input they came from (it will receive more than one).
If you're submitting via ajax, you can use a FormData object and append each file to it, then submit that.
Here's a quick and dirty example maintaining the files in a FormData object:
let nextFileNum = 1;
const formData = new FormData();
const fileList = document.getElementById("file-list");
document.getElementById("inputs").addEventListener("input", function() {
let input = event.target.closest("input[type=file]");
if (!input) {
return;
}
for (const file of input.files) {
const fileId = `file${nextFileNum++}`;
formData.append(fileId, file, file.name);
debugShowCurrentFiles("added");
let div = document.createElement("div");
// This is a Q&D sketch, needs a11y
div.innerHTML = "<span tabindex class=delete>[X]</span><span class=filename></span>";
div.querySelector(".filename").textContent = file.name;
div.querySelector(".delete").addEventListener("click", function() {
formData.delete(fileId);
debugShowCurrentFiles("deleted");
div.remove();
div = null;
});
fileList.appendChild(div);
}
this.removeChild(input);
this.insertAdjacentHTML("beforeend", input.outerHTML);
input = null;
});
function debugShowCurrentFiles(action) {
const contents = [...formData.entries()];
console.log(`--- ${action}, updated formData contents (${contents.length}):`);
for (const [key, value] of contents) {
console.log(`${key}: ${value.name}`);
}
}
#file-list .delete {
margin-right: 2em;
cursor: pointer;
}
<div id="inputs">
<input type="file" multiple>
</div>
<div id="file-list"></div>
You can do this with FileList, heres an article about it.
Also added code snippet which outputs file name and type after you submit the form just for visualization.
let form = document.getElementById('file_drop_form');
function getFiles(event) {
event.preventDefault();
let files = document.getElementById('file').files;
for(let i = 0; i < files.length; i++) {
document.write(`Title: ${files[i].name}; Type: ${files[i].type} <br>`);
}
}
form.addEventListener('submit', getFiles);
<form id="file_drop_form" method="post" enctype="multipart/form-data">
<div>
<label for="file">Drop your files here</label>
<input type="file" id="file" name="file" required multiple>
</div>
<input type="submit" value="Submit">
</form>
Related
My goal is to get a way to upload multiple images and also set in which order they should be displayed later on (it's for an ecommerce website). I have an idea which seems to work. But I would like to know if there is a better way of doing this. Here is my code. Let's assume the number of images is limited to 3.
One input for multiple images.
Preview images and make them sortable.
Store the order in hidden inputs.
Store the images in the filesystem.
Add the path and order index of every image to the database.
HTML
<!-- One input for all images -->
<input type="file" name="images[]" onchange="previewImages(this)" multiple>
<!-- This <div> will be made sortable with SortableJS -->
<div id="preview-parent">
<div class="preview">
<!--
Hidden input to save the order of images.
The idea is to have images_order[name_of_image] = index.
name_of_image and index will be set with JavaScript
-->
<input class="order-input" type="hidden" name="images_order[]" value="0">
<!-- <img> is for preview -->
<img class="preview-image" src="" alt="Image1">
</div>
<div class="preview">
<input class="order-input" type="hidden" name="images_order[]" value="1">
<img class="preview-image" src="" alt="Image2">
</div>
<div class="preview">
<input class="order-input" type="hidden" name="images_order[]" value="2">
<img class="preview-image" src="" alt="Image3">
</div>
</div>
JavaScript
function previewImages(input) {
// First I take the images
var file = input.files
// Then I go through each of them. This code is based on the explanation
// from https://developer.mozilla.org/en-US/docs/Web/API/FileReader/readAsDataURL
for (var i = 0; i < file.length; i++) {
let preview = document.querySelectorAll('.preview-image')[i]
let reader = new FileReader()
reader.onloadend = function () {
preview.src = reader.result
}
if (file[i]) {
reader.readAsDataURL(file[i])
// In addition to previewing images I take their names
// and put them into my hidden inputs
let order_inputs = document.querySelectorAll('.order-input')
order_inputs[i].name = 'images_order[' + file[i].name +']'
} else {
preview.src = ""
}
}
}
// I make the images sortable by means of SortableJS
var el = document.getElementById('preview-parent')
new Sortable(el, {
animation: 150,
// This function updates the values of my hidden inputs
// every time a change is made
onEnd: function (event) {
let order_inputs = document.querySelectorAll('.order-input')
for (var i = 0; i < order_inputs.length; i++) {
order_inputs[i].value = [i]
}
}
})
function previewImages(input) {
var file = input.files
for (var i = 0; i < file.length; i++) {
let preview = document.querySelectorAll('.preview-image')[i]
let reader = new FileReader()
reader.onloadend = function () {
preview.src = reader.result
}
if (file[i]) {
reader.readAsDataURL(file[i])
let order_inputs = document.querySelectorAll('.order-input')
order_inputs[i].name = 'images_order[' + file[i].name +']'
} else {
preview.src = ""
}
}
}
var el = document.getElementById('preview-parent')
new Sortable(el, {
animation: 150,
onEnd: function (event) {
let order_inputs = document.querySelectorAll('.order-input')
for (var i = 0; i < order_inputs.length; i++) {
order_inputs[i].value = [i]
}
}
})
#preview-parent {
display: flex;
gap: 1rem;
margin: 1rem;
}
.preview {
height: 100px;
width: 100px;
padding: 1rem;
border: 1px solid grey;
}
.preview img {
max-height: 100%;
max-width: 100%;
}
<script src="https://cdn.jsdelivr.net/npm/sortablejs#latest/Sortable.min.js"></script>
<input type="file" name="images[]" onchange="previewImages(this)" multiple>
<div id="preview-parent">
<div class="preview">
<input class="order-input" type="hidden" name="images_order[]" value="0">
<img class="preview-image" src="" alt="Image1">
</div>
<div class="preview">
<input class="order-input" type="hidden" name="images_order[]" value="1">
<img class="preview-image" src="" alt="Image2">
</div>
<div class="preview">
<input class="order-input" type="hidden" name="images_order[]" value="2">
<img class="preview-image" src="" alt="Image3">
</div>
</div>
I haven't figured out yet how to limit the number of submitted images. But I saw a number of discussions about that, so I hope it will not be a problem.
PHP. The next step is done by means of PHP (CodeIgniter 4). I take the images, store them in my filesystem. Also I add the path to every image and its order index (taken from the hidden input) to the database. Later when a user will open certain product, the data will be taken from the database and ordered by order index. So basically my controller has this:
// I inserted the product before and can get its id
$product_id = $this->products->insertID();
// This line is just for reference, I actually create $input earlier
$input = $this->request->getPost();
// Here I take all the images as suggested in CodeIgniter docs
if($imagefile = $this->request->getFiles())
{
foreach($imagefile['images'] as $img)
{
if ($img->isValid() && ! $img->hasMoved())
{
// Store each image
$name = $img->getName();
$img->move('assets/images/'.$product_id, $name);
// Add info about the image to the database
$data = [
'product_id' => $product_id,
'path' => base_url('assets/images/'.$product_id.'/'.$name),
'order_index' => $input['images_order'][$name],
];
$this->imagesModel->insert($data);
}
}
}
It would be perfect if I could upload multiple images at once and then not only reorder them but also be able to replace one of the images. If someone could share any ideas, I will appreciate it very much!
After long time I have returned to this project and made further research. So I would like to share my solution.
So I have decided that a convenient option will be to have only one input for multiple images. The user clicks it and chooses the needed images. If he needs to add more images after this, he clicks the same input again and the new images are added to the list. All images immediately appear as previews with the "delete" button. So if the user needs to replace one image, he can delete it, upload a new image and move it to the needed place.
The PHP code from my post does not require any changes. The work is done in Javascript. There are lots of lines of code, but a big part of them is simply for dynamic generating of previews. Please see the snippet.
// DataTransfer allows updating files in input
var dataTransfer = new DataTransfer()
const form = document.querySelector('#form')
const input = document.querySelector('#input')
input.addEventListener('change', () => {
let files = input.files
for (let i = 0; i < files.length; i++) {
// A new upload must not replace images but be added
dataTransfer.items.add(files[i])
// Generate previews using FileReader
let reader, preview, previewImage
reader = new FileReader()
preview = document.createElement('div')
previewImage = document.createElement('img')
deleteButton = document.createElement('button')
orderInput = document.createElement('input')
preview.classList.add('preview')
document.querySelector('#preview-parent').appendChild(preview)
deleteButton.setAttribute('data-index', i)
deleteButton.setAttribute('onclick', 'deleteImage(this)')
deleteButton.innerText = 'Delete'
orderInput.type = 'hidden'
orderInput.name = 'images_order[' + files[i].name + ']'
preview.appendChild(previewImage)
preview.appendChild(deleteButton)
preview.appendChild(orderInput)
reader.readAsDataURL(files[i])
reader.onloadend = () => {
previewImage.src = reader.result
}
}
// Update order values for all images
updateOrder()
// Finally update input files that will be sumbitted
input.files = dataTransfer.files
})
const updateOrder = () => {
let orderInputs = document.querySelectorAll('input[name^="images_order"]')
let deleteButtons = document.querySelectorAll('button[data-index]')
for (let i = 0; i < orderInputs.length; i++) {
orderInputs[i].value = [i]
deleteButtons[i].dataset.index = [i]
// Just to show that order is always correct I add index here
deleteButtons[i].innerText = 'Delete (index ' + i + ')'
}
}
const deleteImage = (item) => {
// Remove image from DataTransfer and update input
dataTransfer.items.remove(item.dataset.index)
input.files = dataTransfer.files
// Delete element from DOM and update order
item.parentNode.remove()
updateOrder()
}
// I make the images sortable by means of SortableJS
const el = document.getElementById('preview-parent')
new Sortable(el, {
animation: 150,
// Update order values every time a change is made
onEnd: (event) => {
updateOrder()
}
})
#preview-parent {
display: flex;
}
.preview {
display: flex;
flex-direction: column;
margin: 1rem;
}
img {
width: 100px;
height: 100px;
object-fit: cover;
}
<script src="https://cdn.jsdelivr.net/npm/sortablejs#latest/Sortable.min.js"></script>
<form method="post" enctype="multipart/form-data" id="form">
<input type="file" name="images[]" id="input" multiple>
<button type="submit">Save</button>
</form>
<!-- This <div> will be made sortable with SortableJS -->
<div id="preview-parent">
<!-- After upload Javascript will generate previews with this pattern
<div class="preview">
<img src="...">
<button data-index=0>Delete</button>
<input type="hidden" name="images_order['name']" value=0>
</div>
-->
</div>
I have the following problem that I cannot solve
is a form of this type
in HTML
<button (click)="addform()">agregar formulario</button>
<div class="conten-form">
<div class="MyForm">
<label>Nombre</label>
<input type="text" class="name">
<label>descripcion</label>
<input type="text" class="description">
<label>Foto</label>
<div class="img-cont">
<div class="img">
<img src="{{img}}">
</div>
<div class="addimg">
<input type="file" (change)="createimg($event)">
</div>
</div>
</div>
<div class="AddForm"></div>
<input type="buttom" value="enviar" (click)="enviarform()">
</div>
in TS
img : any; //to show
imgfile : any; //to send it through the form
constructor(...){...}
addform(){
let addform = document.querySelectorAll('.AddForm');
let myform = document.querySelectorAll('.MyForm');
let cloneform = myform.cloneNode(true);
addform.appendChild(cloneform);
}
createimg(event){
this.imgfile = event.target.files[0];
const reader = new FileReader();
reader.readAsDataURL(this.imgfile);
reader.onload = () => {
this.img = reader.result;
};
}
enviarform(event){
let nombre = document.querySelectorAll(".name");
let description = document.querySelectorAll(".description");
let formdata = new FormData;
//add all inputs class name
for (let i = 0; i < nombre .length; i++) {
let stringname = (nombre.[i] as HTMLTextAreaElement).value;
formdata.append('name',stringname);
}
//add all inputs class description
for (let i = 0; i < description.length; i++) {
let stringdescription = (description.[i] as HTMLTextAreaElement).value;
formdata.append('description',stringdescription );
}
//send the form
}
As you will see, I can add more forms with the add button, cloning the first one, the part of the text inputs I have solved to add as many as I want, but in the part of the inputs for the image I have no idea how to do it, the operation is that after attaching an image to the input, I get a preview image of what I am going to attach in the div.class = img, this makes it only work in the first form, and it no longer works in the forms that I add dynamically, as it could fix this issue? taking into account that I have to send it through the formdata in a single shipment, I thank you in advance.
you should not use
let addform = document.querySelectorAll('.AddForm');
let myform = document.querySelectorAll('.MyForm');
let cloneform = myform.cloneNode(true);
at all. to add forms. instead you should create a separate component for each form.
check my question earlier on stackoverflow to get what I mean.
more specifically check the answer stackblitz.
I have a problem while uploading files using a drop area. It seems that files get converted to strings when they arrive at the backend. I'm adding the file objects to a new array because I want the users to be able to remove unwanted files before they submit the form.
The form looks like this:
<form action="" class="dropzone" id="image_upload" enctype="multipart/form-data">
<div class="upload-input">
<label for="delivery_address" id="delivery_address_label">Delivery address</label>
<input type="text" name="delivery_address" id="delivery_address" class="form-control" />
</div>
<div class="" id="drop-area">
<p>Upload multiple files with the file dialog or by dragging and dropping images onto the dashed
region
</p>
</div>
<div class="upload-input">
<input class="btn btn-info w-100" type="submit" id="btnUpload" value="Send" />
</div>
</form>
Javascript:
let dropArea = document.getElementById("drop-area");
let fileList = [];
['dragenter', 'dragover', 'dragleave', 'drop'].forEach(eventName => {
dropArea.addEventListener(eventName, preventDefaults, false)
})
function preventDefaults(e) {
e.preventDefault()
e.stopPropagation()
}
dropArea.addEventListener('drop', handleDrop, false)
function handleDrop(e) {
let dt = e.dataTransfer;
let files = dt.files;
handleFiles(files);
}
function handleFiles(files) {
files = [...files];
files.forEach(addFiles);
}
function addFiles(file) {
fileList.push(file);
}
btnUpload.addEventListener("click", function(evt) {
evt.preventDefault();
const xhr = new XMLHttpRequest();
const form = document.getElementById("image_upload");
const formData = new FormData(form);
console.log(fileList);
formData.append("fileList", fileList);
xhr.open("POST", "add.php");
xhr.onreadystatechange = function() {
document.getElementById("phpResponse").innerHTML = this.responseText;
};
xhr.send(formData);
});
And in the PHP file I'm just var dumping $_FILES for now to see what's going through:
var_dump($_FILES);
Which returns
array(0) { }
var_dump($_POST) returns:
array(3) { ["delivery_type"]=> string(14) "Latvijas pasts" ["delivery_address"]=> string(6) "qweeqe" ["fileList"]=> string(27) "[object File],[object File]" }
I can't find where the problem is. The form is set to enctype="multipart/form-data". Before sending the form I console.log the fileList variable and it looks like the files are still files:
As suggested, I have to loop through every instance of File in the fileList array and append each File to FormData individually.
This part:
formData.append("fileList", fileList);;
Becomes:
for (let i = 0; i < fileList.length; i++) {
formData.append("fileList[]", fileList[i]);
}
And on the backend I can loop through every file:
foreach($_FILES['fileList']['tmp_name'] as $key => $tmp_name){
echo $_FILES['fileList']['name'][$key] . "<br />";
}
I have two buttons ... when clicked they display some text in a input field. I use some simple javascript to select which text to display, the one defined under the button with id="blabla1" or the one under the button with id="blabla2".
Is it possible to display the text defined in an external .txt file?
It is working fine with the text defined as value under the input button:
<input type="hidden" id="SupSite1Title" value="Subsite1 Title!"><br>
but i want text from a txt file instead.
<body>
<div id="leftnav">
<ul>
<li><input type="text" id="TextField1"><br><br></li>
</ul>
</div>
<div id="rightnav">
<ul>
<li><button id="blabla1" onclick="myFunction1()">Side1</button></li>
<li><button id="blabla2" onclick="myFunction2()">Side2</button></li>
</ul>
</div>
<input type="hidden" id="SupSite1Title" value="Subsite1 Title!"><br>
<input type="hidden" id="SupSite2Title" value="Subsite2 Title!"><br>
<script>
function myFunction1() {document.getElementById("TextField1").value =document.getElementById("SupSite1Title").value;
}
</script>
<script>
function myFunction2() {document.getElementById("TextField1").value =document.getElementById("SupSite2Title").value;
}
</script>
If you want to display the text content of the .txt file ... you can use an API called FileReader API (you need to check if your browser supports that)
here is how you can do it :
UPDATED :
var file1 = document.getElementById('file1');
var file2 = document.getElementById('file2');
document.getElementById('bOne').addEventListener("click", function(){getFile(file1)})
document.getElementById('bTwo').addEventListener("click", function(){getFile(file2)})
function getFile(target) {
const input = target;
if ('files' in input && input.files.length > 0) {
placeFileContent(
document.getElementById('display'),
input.files[0])
}
}
function placeFileContent(target, file) {
readFileContent(file).then(content => {
target.value = content
}).catch(error => console.log(error))
}
function readFileContent(file) {
const reader = new FileReader()
return new Promise((resolve, reject) => {
reader.onload = event => resolve(event.target.result)
reader.onerror = error => reject(error)
reader.readAsText(file)
})
}
label {
display : block;
margin-top : 40px;
margin-bottom : 20px;
}
<label for="file1">Upload file 1 : </label>
<input type="file" accept=".txt" id="file1" name="file1">
<label for="file2">Upload file 2 : </label>
<input type="file" accept=".txt" id="file2" name="file2">
<button id="bOne">Display file1</button>
<button id="bTwo">Display file2</button>
<label for="file2">Selected file : </label>
<input type="text" id="display" for="display">
METHOD N°2 (data fetching from a server) :
function fetchData(buttonNumber) {
var btn1 = document.getElementById('b1')
var btn2 = document.getElementById('b2')
var display = document.getElementById('display')
//fetching data
if (buttonNumber == 1) {
//replace 'file1.txt' with your file URL
fetch('file1.txt').then(x => {
x.text().then(function(text) {
display.value = text
});
})
} else {
//replace 'file2.txt' with your file URL
fetch('file2.txt').then(x => {
x.text().then(function(text) {
display.value = text
});
})
}
}
#b1,
#b2 {
display: block;
margin: 40px;
}
<button id="b1" onclick="fetchData(1)">Get file 1 and show it</button>
<button id="b2" onclick="fetchData(2)">Get file 2 and show it</button>
<label for="file2">Selected file : </label>
<input type="text" id="display" for="display">
If you want to read the contents of a text file you cannot load it from local file system. You should put it on server and load it from there.
Give the input field the attributes type="file" and accept=".txt", and that should work
<input type="file" accept=".txt" />
And you can read this .txt file using node.js(Also you can read it with vanilla js), But i prefer node.js like this
const fs = require('fs');
const fileData = fs.readFileSync('fileName.txt', 'utf-8');
console.log(fileData) // Whatever inside .txt file
Update according to comment:
Suppose in your project folder, you have one index.html file and one index.js file. Create two .txt file named as file1.txt and file2.txt And write something on those file. NOTE: For simplicity i am writing solution using jQuery.
index.html
<body>
<p id="text-field"></p>
<button id="btn1">Button 1</button>
<button id="btn2">Button 2</button>
</body>
index.js
const fs = require('fs');
let fileData = '';
$('#btn1').click(()=> {
fileData = fs.readFileSync('file1.txt', 'utf-8');
$('#text-field').append(fileData);
});
$('#btn2').click(()=> {
fileData = fs.readFileSync('file2.txt', 'utf-8');
$('#text-field').append(fileData);
});
That's it. According to button click text will be append into p element.
You can handle two button click with one function also, like this
$('button').click(event => {
event.stopImmediatePropagation();
event.stopPropagation();
if($(event.target).attr('id') === 'btn1') {
fileData = fs.readFileSync('file1.txt', 'utf-8');
$('#text-field').append(fileData);
}else if($(event.target).attr('id') === 'btn2') {
fileData = fs.readFileSync('file2.txt', 'utf-8');
$('#text-field').append(fileData);
}
});
How to remove specific file from files selected with input type with multiple attribute?
<input type="file" (change)="onFileChange($event)" #fileInput multiple>
I want to delete one of the selected file.
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/file
https://jsfiddle.net/Sagokharche/eL3eg6k4/
Do you need it to be impossible to choose? Then use HTML Input file accept property. accept="image/png" for instance.
Or you want it to filter from the input after the user selected it?
Then you should use a custom directive or check for the file types in the ts code upon upload.
EDIT
in that case, in your code:
onFileChange(event) {
const fileList = event.target.files;
console.log("User selected fileList:", fileList)
Array.from(fileList).filter(
item => {
console.log("file mime type:", item['type'])
})
const filesToUpload = Array.from(fileList).filter(
item => { return item['type'] != "application/zip" })
console.log("reduced list:", filesToUpload)
}
Working stackblitz example here.
You can access the inputs FileList-object in .ts side like this:
onFileChange(event) {
console.log(event.srcElement.files);
}
Edit:
If you are looking for a solution how to make dynamic form (add and delete inputs), then have a look at this answer and demo:
Angular 4 Form FormArray Add a Button to add or delete a form input row
In your hmtl code
<div class="row">
<div class="col-md-2 productAddfromImages" *ngFor='let url of imageurls; let i = index'>
<img class="img-fluid" [src]="url.base64String">
<a (click)="removeImage(i)" class="btn btn-xs btn-danger">Remove</a>
</div>
</div>
Remove function
removeImage(i) {
this.imageurls.splice(i, 1);
}
Add Function
onSelectFile(event) {
if (event.target.files && event.target.files[0]) {
var filesAmount = event.target.files.length;
for (let i = 0; i < filesAmount; i++) {
var reader = new FileReader();
reader.onload = (event: any) => {
this.imageurls.push({ base64String: event.target.result, });
}
reader.readAsDataURL(event.target.files[i]);
}
}
}
}
For more details:https://findandsolve.com/articles/how-to-upload-and-remove-multiple-image-using-anular-code-example