Achieve Invisible Upload in JavaScript Uploader control

08 May 2023 / 1 minute to read

You can achieve the invisible upload feature by using the selected event in uploader component. Refer to the following example.

Source

Preview

app.ts

index.html

index.css

import { Uploader, SelectedEventArgs } from '@syncfusion/ej2-inputs';
import { createElement } from '@syncfusion/ej2-base';

let uploadObj: Uploader = new Uploader({
    asyncSettings: {
        saveUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Save',
        removeUrl: 'https://ej2.syncfusion.com/services/api/uploadbox/Remove'
    },
    selected : onupload,
    locale: 'en-US',
    allowedExtensions: '.png, .jpg, .jpeg'
});
uploadObj.appendTo('#fileupload')

function onupload(args: SelectedEventArgs){
    for(let i = 0; i< args.filesData.length ; i++){
        let liparentDiv = createElement('div',  { className: 'image-list'});
        let liImage = createElement('img',  { className: 'image'});
        liparentDiv.appendChild(liImage);
        readURL(liImage, args.filesData[i]);
        document.getElementById('preview').appendChild(liparentDiv);
    }
    args.cancel=true;
}

function readURL(liImage: HTMLElement, file: any) {
    let imgPreview: HTMLImageElement = liImage as HTMLImageElement;
    let imageFile: File = file.rawFile;
    let reader: FileReader = new FileReader();
    reader.addEventListener( 'load', () => {
        imgPreview.src = reader.result;
    }, false);
    if (imageFile) {
        reader.readAsDataURL(imageFile);
    }
};

<!DOCTYPE html>
<html lang="en">

<head>
            
    <title>Essential JS 2 Uploader</title>
    <meta charset="utf-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <meta name="description" content="Essential JS 2 Uploader Component" />
    <meta name="author" content="Syncfusion" />
    <link href="index.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="//cdn.syncfusion.com/ej2/21.2.3/ej2-buttons/styles/material.css" rel="stylesheet" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/systemjs/0.19.38/system.js"></script>
    <script src="systemjs.config.js"></script>
</head>
<body>
    <div id='loader'>Loading....</div>
    <div id='preview'></div>
    <div id='container'>
        <input type="file" id="fileupload" name="UploadFiles"/>
    </div>
</body>
</html>

#container {
  visibility: hidden;
  margin: 10px;
}

#loader {
  color: #008cff;
  font-family: 'Helvetica Neue','calibiri';
  font-size: 14px;
  height: 40px;
  left: 45%;
  position: absolute;
  top: 45%;
  width: 30%;
}

#preview {
  border: 2px dashed #ddd;
  padding: 15px;
}

.image-list {
  width: 134px;
  height: 117px;
  margin-right: 4px;
  border: 1px solid lightgrey;
  display: inline-block;
}

.image {
  width: 134px;
  height: 117px;
  margin-right: 4px;
  display: inline-block;
}

.e-control {
  border : 0;
}

.e-control ul {
  border: 1px solid #ddd;
}

.e-control .e-file-select,
.e-control .e-file-drop {
  display: none;
}

You can also explore JavaScript File Upload feature tour page for its groundbreaking features. You can also explore our JavaScript File Upload example to understand how to browse the files which you want to upload to the server.