react-dropzone

What is react-dropzone?

The react-dropzone npm package is a simple and highly customizable dropzone component for React applications. It allows users to drag and drop files into an area of a web page or click to select files through the file explorer. It is designed to provide developers with a flexible and easy-to-use interface for handling file uploads.

What are react-dropzone's main functionalities?

Basic File Drop

This feature allows users to create a basic dropzone area where files can be dragged and dropped or selected through a file dialog.

import React from 'react';
import { useDropzone } from 'react-dropzone';

function BasicDropzone() {
  const { getRootProps, getInputProps } = useDropzone();

  return (
    <div {...getRootProps()}>
      <input {...getInputProps()} />
      <p>Drag 'n' drop some files here, or click to select files</p>
    </div>
  );
}

export default BasicDropzone;

Accepting Specific File Types

This feature allows developers to specify which file types the dropzone will accept, limiting the user to only select or drag those types.

import React from 'react';
import { useDropzone } from 'react-dropzone';

function SpecificTypeDropzone() {
  const { getRootProps, getInputProps } = useDropzone({
    accept: 'image/*'
  });

  return (
    <div {...getRootProps()}>
      <input {...getInputProps()} />
      <p>Drag 'n' drop some images here, or click to select images</p>
    </div>
  );
}

export default SpecificTypeDropzone;

Styling Dropzone Based on Drag State

This feature allows developers to apply different styles to the dropzone depending on whether files are being dragged over it.

import React from 'react';
import { useDropzone } from 'react-dropzone';

function StyledDropzone() {
  const { getRootProps, getInputProps, isDragActive } = useDropzone();

  return (
    <div {...getRootProps()} style={{
      border: '2px dashed #eeeeee',
      backgroundColor: isDragActive ? '#e0e0e0' : '#fafafa',
      padding: '20px'
    }}>
      <input {...getInputProps()} />
      {
        isDragActive ?
          <p>Drop the files here ...</p> :
          <p>Drag 'n' drop some files here, or click to select files</p>
      }
    </div>
  );
}

export default StyledDropzone;

Handling File Previews

This feature allows developers to handle file previews by creating image thumbnails for dropped files.

import React, { useState } from 'react';
import { useDropzone } from 'react-dropzone';

function FilePreviewDropzone() {
  const [files, setFiles] = useState([]);
  const { getRootProps, getInputProps } = useDropzone({
    onDrop: acceptedFiles => {
      setFiles(acceptedFiles.map(file => Object.assign(file, {
        preview: URL.createObjectURL(file)
      })));
    }
  });

  const images = files.map(file => (
    <div key={file.name}>
      <img src={file.preview} style={{ width: '200px' }} alt='preview' />
    </div>
  ));

  return (
    <section className='container'>
      <div {...getRootProps()}>
        <input {...getInputProps()} />
        <p>Drag 'n' drop some files here, or click to select files</p>
      </div>
      <aside>
        <h4>Files</h4>
        {images}
      </aside>
    </section>
  );
}

export default FilePreviewDropzone;

Other packages similar to react-dropzone

dropzone

Dropzone is a standalone JavaScript library that provides drag-and-drop file uploads with image previews. It's more feature-rich out of the box compared to react-dropzone, but it's not a React component by default, which means it might require additional integration effort in React applications.

react-dropzone-uploader

React Dropzone Uploader is a React component that provides a dropzone as well as file previews and upload status. It offers more built-in features for handling uploads compared to react-dropzone, but it might be less flexible if you need to heavily customize the upload behavior.

filepond

FilePond is a flexible and fun JavaScript file upload library that can be turned into a React component using react-filepond. It provides a rich set of features like image optimization, file validation, and multiple file handling. It's a more comprehensive solution compared to react-dropzone but may be heavier if you only need a simple dropzone.

README

react-dropzone

Simple HTML5-compliant drag'n'drop zone for files built with React.js.

Documentation and examples: https://react-dropzone.js.org Source code: https://github.com/react-dropzone/react-dropzone/

---

Looking for maintainers: https://github.com/react-dropzone/react-dropzone/issues/479

---

Installation

Install it from npm and include it in your React build process (using Webpack, Browserify, etc).

npm install --save react-dropzone

or:

yarn add react-dropzone

Usage

Import Dropzone in your React component:

import Dropzone from 'react-dropzone'

and specify the onDrop method that accepts two arguments. The first argument represents the accepted files and the second argument the rejected files.

function onDrop(acceptedFiles, rejectedFiles) {
  // do stuff with files...
}

Files accepted or rejected based on accept prop. This must be a valid MIME type according to input element specification.

Please note that onDrop method will always be called regardless if dropped file was accepted or rejected. The onDropAccepted method will be called if all dropped files were accepted and the onDropRejected method will be called if any of the dropped files was rejected.

Using react-dropzone is similar to using a file form field, but instead of getting the files property from the field, you listen to the onDrop callback to handle the files. Simple explanation here: http://abandon.ie/notebook/simple-file-uploads-using-jquery-ajax

Specifying the onDrop method, provides you with an array of Files which you can then send to a server. For example, with SuperAgent as a http/ajax library:

onDrop: acceptedFiles => {
    const req = request.post('/upload');
    acceptedFiles.forEach(file => {
        req.attach(file.name, file);
    });
    req.end(callback);
}

Warning: On most recent browsers versions, the files given by onDrop won't have properties path or fullPath, see this SO question and this issue. If you want to access file content you have to use the FileReader API.

onDrop: acceptedFiles => {
    acceptedFiles.forEach(file => {
        const reader = new FileReader();
        reader.onload = () => {
            const fileAsBinaryString = reader.result;
            // do whatever you want with the file content
        };
        reader.onabort = () => console.log('file reading was aborted');
        reader.onerror = () => console.log('file reading has failed');

        reader.readAsBinaryString(file);
    });
}

PropTypes

See https://react-dropzone.netlify.com/#proptypes

Word of caution when working with previews

Important: react-dropzone doesn't manage dropped files. You need to destroy the object URL yourself whenever you don't need the preview by calling window.URL.revokeObjectURL(file.preview); to avoid memory leaks.

Testing

Important: react-dropzone makes its drag'n'drop callbacks asynchronous to enable promise based getDataTransfer functions. In order to properly test this, you may want to utilize a helper function to run all promises like this:

const flushPromises = () => new Promise(resolve => setImmediate(resolve));

Example with enzyme 3:

it('tests drag state', async () => {
  const flushPromises = () => new Promise(resolve => setImmediate(resolve));
  const DummyChildComponent = () => null
  const dropzone = mount(
    <Dropzone>{props => <DummyChildComponent {...props} />}</Dropzone>
  )
  dropzone.simulate('dragEnter', {
    dataTransfer: { files: files.concat(images) }
  })
  await flushPromises(dropzone)
  dropzone.update()
  
  const child = updatedDropzone.find(DummyChildComponent)
  expect(child).toHaveProp('isDragActive', true)
  expect(child).toHaveProp('isDragAccept', false)
  expect(child).toHaveProp('isDragReject', true)
})

Remember to update your mounted component before asserting any props. A complete example for this can be found in react-dropzones own test suite.

Support

Backers

Support us with a monthly donation and help us continue our activities. [Become a backer]

Sponsors

Become a sponsor and get your logo on our README on Github with a link to your site. [Become a sponsor]

License

MIT