Add confirm dialog to remove the files in EJ2 TypeScript Uploader control

You can customize the uploader component using confirm dialog before removing the files. Here, ej2 dialog is used as confirm dialog. Refer to the following example.

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

let removeFile: FileInfo[];

let uploadObj: Uploader = new Uploader({
    asyncSettings: {
      saveUrl: 'https://services.syncfusion.com/js/production/api/FileUploader/Save',
      removeUrl: 'https://services.syncfusion.com/js/production/api/FileUploader/Remove'
    },
    removing: onremove

});
uploadObj.appendTo('#fileupload');

// Initialize Dialog component
let dialog: Dialog = new Dialog({
    content: 'Are you sure want to remove the file?',
    buttons: [{'click': () => { onClick() }, buttonModel: { content: 'OK', cssClass: 'e-flat', isPrimary: true }},
        {'click': () => {dialog.hide(); }, buttonModel: { content: 'Cancel', cssClass: 'e-flat'} }],
    width: '250px',
    visible: false,
    target: '#container'
});
dialog.appendTo('#dialog');

function onClick() {
  dialog.hide();
  uploadObj.remove(removeFile[0], false, true);
}

function onremove(args: any) {
  removeFile=[];
  args.cancel = true;
  removeFile.push(args.filesData);
  dialog.show();
}
<!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="https://cdn.syncfusion.com/ej2/25.1.35/ej2-base/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-inputs/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/ej2-popups/styles/material.css" rel="stylesheet" />
    <link href="https://cdn.syncfusion.com/ej2/25.1.35/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>
<script src="https://cdn.syncfusion.com/ej2/syncfusion-helper.js" type ="text/javascript"></script>
</head>
<body>
    <div id='loader'>Loading....</div>
    <div id='container'>
        <input type="file" id="fileupload" name="UploadFiles"/>
        <div id='dialog'></div>
    </div>
</body>
</html>
html,
body,    
#container {
    height: 100%;
    overflow: hidden;
    margin: auto 30px;
    padding: 20px 0;
}

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

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.