express-fileupload

What is express-fileupload?

The express-fileupload npm package is a middleware for handling file uploads in Express applications. It simplifies the process of uploading files to a server by providing an easy-to-use interface and various configuration options.

What are express-fileupload's main functionalities?

Basic File Upload

This feature allows for basic file uploads. The code sets up an Express server with the express-fileupload middleware, and defines a POST route to handle file uploads. Uploaded files are moved to a specified directory on the server.

const express = require('express');
const fileUpload = require('express-fileupload');
const app = express();

app.use(fileUpload());

app.post('/upload', (req, res) => {
  if (!req.files || Object.keys(req.files).length === 0) {
    return res.status(400).send('No files were uploaded.');
  }

  let sampleFile = req.files.sampleFile;

  sampleFile.mv('/somewhere/on/your/server/filename.jpg', function(err) {
    if (err)
      return res.status(500).send(err);

    res.send('File uploaded!');
  });
});

app.listen(3000, () => {
  console.log('Server started on http://localhost:3000');
});

File Size Limit

This feature allows setting a file size limit for uploads. The code configures the express-fileupload middleware to limit the file size to 50MB.

const express = require('express');
const fileUpload = require('express-fileupload');
const app = express();

app.use(fileUpload({
  limits: { fileSize: 50 * 1024 * 1024 }, // 50MB
}));

app.post('/upload', (req, res) => {
  if (!req.files || Object.keys(req.files).length === 0) {
    return res.status(400).send('No files were uploaded.');
  }

  let sampleFile = req.files.sampleFile;

  sampleFile.mv('/somewhere/on/your/server/filename.jpg', function(err) {
    if (err)
      return res.status(500).send(err);

    res.send('File uploaded!');
  });
});

app.listen(3000, () => {
  console.log('Server started on http://localhost:3000');
});

Using Temp Files

This feature allows the use of temporary files during the upload process. The code configures the express-fileupload middleware to use temporary files and specifies a directory for these temp files.

const express = require('express');
const fileUpload = require('express-fileupload');
const app = express();

app.use(fileUpload({
  useTempFiles: true,
  tempFileDir: '/tmp/'
}));

app.post('/upload', (req, res) => {
  if (!req.files || Object.keys(req.files).length === 0) {
    return res.status(400).send('No files were uploaded.');
  }

  let sampleFile = req.files.sampleFile;

  sampleFile.mv('/somewhere/on/your/server/filename.jpg', function(err) {
    if (err)
      return res.status(500).send(err);

    res.send('File uploaded!');
  });
});

app.listen(3000, () => {
  console.log('Server started on http://localhost:3000');
});

Other packages similar to express-fileupload

multer

Multer is a Node.js middleware for handling multipart/form-data, which is primarily used for uploading files. It is highly configurable and allows for fine-grained control over file storage and handling. Compared to express-fileupload, Multer offers more flexibility and control over file handling, but it may require more setup and configuration.

formidable

Formidable is a Node.js module for parsing form data, especially file uploads. It is a low-level library that provides a lot of control over file uploads and form parsing. Compared to express-fileupload, Formidable is more complex and offers more detailed control over the file upload process, but it may be more difficult to use for simple use cases.

busboy

Busboy is a Node.js module for parsing incoming HTML form data. It is a low-level library that provides a stream-based interface for handling file uploads. Compared to express-fileupload, Busboy offers more control and efficiency for handling large file uploads, but it requires more setup and understanding of streams in Node.js.

README

express-fileupload

Simple express middleware for uploading files.

Version 1.1.1 Breaking Changes

Breaking change to md5 handling:

• md5 value contains md5 hash instead of a function to compute it.
• md5 now can be used with useTempFiles: true.

Version 1.0.0 Breaking Changes

Breaking change to md5 handling. Read about it here.

Install

# With NPM
npm install --save express-fileupload

# With Yarn
yarn add express-fileupload

Usage

When you upload a file, the file will be accessible from req.files.

Example:

• You're uploading a file called car.jpg
• Your input's name field is foo: <input name="foo" type="file" />
• In your express server request, you can access your uploaded file from req.files.foo:

app.post('/upload', function(req, res) {
  console.log(req.files.foo); // the uploaded file object
});

The req.files.foo object will contain the following:

• req.files.foo.name: "car.jpg"
• req.files.foo.mv: A function to move the file elsewhere on your server
• req.files.foo.mimetype: The mimetype of your file
• req.files.foo.data: A buffer representation of your file, returns empty buffer in case useTempFiles option was set to true.
• req.files.foo.tempFilePath: A path to the temporary file in case useTempFiles option was set to true.
• req.files.foo.truncated: A boolean that represents if the file is over the size limit
• req.files.foo.size: Uploaded size in bytes
• req.files.foo.md5: MD5 checksum of the uploaded file

Examples

• Example Project
• Basic File Upload
• Multi-File Upload

Using Busboy Options

Pass in Busboy options directly to the express-fileupload middleware. Check out the Busboy documentation here.

app.use(fileUpload({
  limits: { fileSize: 50 * 1024 * 1024 },
}));

Using useTempFile Options

Use temp files instead of memory for managing the upload process.

app.use(fileUpload({
    useTempFiles : true,
    tempFileDir : '/tmp/'
}));

Available Options

Pass in non-Busboy options directly to the middleware. These are express-fileupload specific options.

Option	Acceptable Values	Details
createParentPath	false (default) true	Automatically creates the directory path specified in .mv(filePathName)
uriDecodeFileNames	false (default) true	Applies uri decoding to file names if set true.
safeFileNames	false (default) true regex	Strips characters from the upload's filename. You can use custom regex to determine what to strip. If set to true, non-alphanumeric characters except dashes and underscores will be stripped. This option is off by default. Example #1 (strip slashes from file names): app.use(fileUpload({ safeFileNames: /\\/g })) Example #2: app.use(fileUpload({ safeFileNames: true }))
preserveExtension	false (default) true Number	Preserves filename extension when using safeFileNames option. If set to true, will default to an extension length of 3. If set to Number, this will be the max allowable extension length. If an extension is smaller than the extension length, it remains untouched. If the extension is longer, it is shifted. Example #1 (true): app.use(fileUpload({ safeFileNames: true, preserveExtension: true })); myFileName.ext --> myFileName.ext Example #2 (max extension length 2, extension shifted): app.use(fileUpload({ safeFileNames: true, preserveExtension: 2 })); myFileName.ext --> myFileNamee.xt
abortOnLimit	false (default) true	Returns a HTTP 413 when the file is bigger than the size limit if true. Otherwise, it will add a truncate = true to the resulting file structure.
responseOnLimit	'File size limit has been reached' (default) String	Response which will be send to client if file size limit exceeded when abortOnLimit set to true.
limitHandler	false (default) function(req, res, next)	User defined limit handler which will be invoked if the file is bigger than configured limits.
useTempFiles	false (default) true	Will use temporary files at the specified tempDir for managing uploads rather than using buffers in memory. This avoids memory issues when uploading large files.
tempFileDir	String (path)	Used with the useTempFiles option. Path to the directory where temp files will be stored during the upload process. Feel free to add trailing slash, but it is not necessary.
parseNested	false (default) true	By default, req.body and req.files are flattened like this: {'name': 'John', 'hobbies[0]': 'Cinema', 'hobbies[1]': 'Bike'} When this option is enabled they are parsed in order to be nested like this: {'name': 'John', 'hobbies': ['Cinema', 'Bike']}

Help Wanted

Looking for additional maintainers. Please contact richardgirges [ at ] gmail.com if you're interested. Pull Requests are welcomed!

Thanks & Credit

Brian White for his stellar work on the Busboy Package and the connect-busboy Package