React File Uploader - Custom Drop Zone

The FileUploader component supports the drag-and-drop functionality to upload files.

In this demo, the dropZone property specifies the HTML element in which you can drag and drop files for upload. The dropZoneEnter and dropZoneLeave events allow you to customize the drop zone when the mouse pointer enters and leaves this zone while dragging the file.

TS JS

Backend API

import React, { useCallback, useState } from 'react'; import FileUploader from 'devextreme-react/file-uploader'; import type { FileUploaderTypes } from 'devextreme-react/file-uploader'; import ProgressBar from 'devextreme-react/progress-bar'; const allowedFileExtensions: string[] = ['.jpg', '.jpeg', '.gif', '.png']; export default function App() { const [isDropZoneActive, setIsDropZoneActive] = useState<boolean>(false); const [imageSource, setImageSource] = useState<string>(''); const [textVisible, setTextVisible] = useState<boolean>(true); const [progressVisible, setProgressVisible] = useState<boolean>(false); const [progressValue, setProgressValue] = useState<number>(0); const onDropZoneEnter = useCallback(({ component, dropZoneElement, event }): void => { if (dropZoneElement.id === 'dropzone-external') { const items = event.originalEvent.dataTransfer.items; const currentAllowedFileExtensions = component.option('allowedFileExtensions'); const draggedFileExtension = `.${items[0].type.replace(/^image\//, '')}`; const isSingleFileDragged = items.length === 1; const isValidFileExtension = currentAllowedFileExtensions.includes(draggedFileExtension); if (isSingleFileDragged && isValidFileExtension) { setIsDropZoneActive(true); } } }, []); const onDropZoneLeave = useCallback((e: FileUploaderTypes.DropZoneLeaveEvent): void => { if (e.dropZoneElement.id === 'dropzone-external') { setIsDropZoneActive(false); } }, []); const onUploaded = useCallback((e: FileUploaderTypes.UploadedEvent): void => { const { file } = e; const fileReader = new FileReader(); fileReader.onload = (): void => { setIsDropZoneActive(false); setImageSource(fileReader.result as string); }; fileReader.readAsDataURL(file); setTextVisible(false); setProgressVisible(false); setProgressValue(0); }, []); const onProgress = useCallback((e: FileUploaderTypes.ProgressEvent): void => { setProgressValue((e.bytesLoaded / e.bytesTotal) * 100); }, []); const onUploadStarted = useCallback(() => { setImageSource(''); setProgressVisible(true); }, []); return ( <div className="widget-container flex-box"> <span>Profile Picture</span> <div id="dropzone-external" className={`flex-box ${isDropZoneActive ? 'dropzone-active' : ''}`}> {imageSource && <img id="dropzone-image" src={imageSource} alt="" />} {textVisible && ( <div id="dropzone-text" className="flex-box"> <span>Drag & Drop the desired file</span> <span>…or click to browse for a file instead.</span> </div> )} <ProgressBar id="upload-progress" min={0} max={100} width="30%" showStatus={false} visible={progressVisible} value={progressValue} ></ProgressBar> </div> <FileUploader id="file-uploader" dialogTrigger="#dropzone-external" dropZone="#dropzone-external" multiple={false} allowedFileExtensions={allowedFileExtensions} uploadMode="instantly" uploadUrl="https://js.devexpress.com/Demos/NetCore/FileUploader/Upload" visible={false} onDropZoneEnter={onDropZoneEnter} onDropZoneLeave={onDropZoneLeave} onUploaded={onUploaded} onProgress={onProgress} onUploadStarted={onUploadStarted} ></FileUploader> </div> ); }

import React, { useCallback, useState } from 'react'; import FileUploader from 'devextreme-react/file-uploader'; import ProgressBar from 'devextreme-react/progress-bar'; const allowedFileExtensions = ['.jpg', '.jpeg', '.gif', '.png']; export default function App() { const [isDropZoneActive, setIsDropZoneActive] = useState(false); const [imageSource, setImageSource] = useState(''); const [textVisible, setTextVisible] = useState(true); const [progressVisible, setProgressVisible] = useState(false); const [progressValue, setProgressValue] = useState(0); const onDropZoneEnter = useCallback(({ component, dropZoneElement, event }) => { if (dropZoneElement.id === 'dropzone-external') { const items = event.originalEvent.dataTransfer.items; const currentAllowedFileExtensions = component.option('allowedFileExtensions'); const draggedFileExtension = `.${items[0].type.replace(/^image\//, '')}`; const isSingleFileDragged = items.length === 1; const isValidFileExtension = currentAllowedFileExtensions.includes(draggedFileExtension); if (isSingleFileDragged && isValidFileExtension) { setIsDropZoneActive(true); } } }, []); const onDropZoneLeave = useCallback((e) => { if (e.dropZoneElement.id === 'dropzone-external') { setIsDropZoneActive(false); } }, []); const onUploaded = useCallback((e) => { const { file } = e; const fileReader = new FileReader(); fileReader.onload = () => { setIsDropZoneActive(false); setImageSource(fileReader.result); }; fileReader.readAsDataURL(file); setTextVisible(false); setProgressVisible(false); setProgressValue(0); }, []); const onProgress = useCallback((e) => { setProgressValue((e.bytesLoaded / e.bytesTotal) * 100); }, []); const onUploadStarted = useCallback(() => { setImageSource(''); setProgressVisible(true); }, []); return ( <div className="widget-container flex-box"> <span>Profile Picture</span> <div id="dropzone-external" className={`flex-box ${isDropZoneActive ? 'dropzone-active' : ''}`} > {imageSource && ( <img id="dropzone-image" src={imageSource} alt="" /> )} {textVisible && ( <div id="dropzone-text" className="flex-box" > <span>Drag & Drop the desired file</span> <span>…or click to browse for a file instead.</span> </div> )} <ProgressBar id="upload-progress" min={0} max={100} width="30%" showStatus={false} visible={progressVisible} value={progressValue} ></ProgressBar> </div> <FileUploader id="file-uploader" dialogTrigger="#dropzone-external" dropZone="#dropzone-external" multiple={false} allowedFileExtensions={allowedFileExtensions} uploadMode="instantly" uploadUrl="https://js.devexpress.com/Demos/NetCore/FileUploader/Upload" visible={false} onDropZoneEnter={onDropZoneEnter} onDropZoneLeave={onDropZoneLeave} onUploaded={onUploaded} onProgress={onProgress} onUploadStarted={onUploadStarted} ></FileUploader> </div> ); }

import React from 'react'; import ReactDOM from 'react-dom'; import App from './App.tsx'; // eslint-disable-next-line import/no-unresolved import 'anti-forgery'; ReactDOM.render( <App />, document.getElementById('app'), );

import React from 'react'; import ReactDOM from 'react-dom'; import App from './App.js'; import 'anti-forgery'; ReactDOM.render(<App />, document.getElementById('app'));

<!DOCTYPE html> <html lang="en"> <head> <title>DevExtreme Demo</title> <meta http-equiv="X-UA-Compatible" content="IE=edge" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=5.0" /> <link rel="stylesheet" type="text/css" href="https://cdn3.devexpress.com/jslib/26.1.5/css/dx.light.css" /> <link rel="stylesheet" type="text/css" href="./bundle.css" /> </head> <body class="dx-viewport"> <div class="demo-container"> <div id="app"></div> </div> <script src="bundles/vendor/react.vendor.js"></script> <script src="./bundle.js"></script> </body> </html>

#dropzone-external { width: 350px; height: 350px; background-color: rgba(0,0,0,0.08); border-width: 2px; border-style: dashed; padding: 10px; border-color: var(--dx-color-border); } #dropzone-external > * { pointer-events: none; } #dropzone-external.dropzone-active { border-style: solid; border-color: var(--dx-color-primary); } .widget-container > span { font-size: 22px; font-weight: bold; margin-bottom: 16px; } #dropzone-image { max-width: 100%; max-height: 100%; } #upload-progress { display: flex; margin-top: 10px; } .flex-box { display: flex; flex-direction: column; justify-content: center; align-items: center; }

Allowed file extensions: .jpg, .jpeg, .gif, .png

Maximum file size: 4 MB