expressjsHow can I use Express.js to upload a file?

Express.js is a web application framework for Node.js that can be used for uploading files. To use Express.js to upload a file, you will need to install the Express.js package and create an Express.js application.

Example code

const express = require('express');
const app = express();
const multer = require('multer');
const upload = multer({dest: 'uploads/'});

app.post('/upload', upload.single('myFile'), (req, res, next) => {
    const file = req.file
    if (!file) {
      const error = new Error('Please upload a file')
      error.httpStatusCode = 400
      return next(error)
    }
    res.send(file)
})

app.listen(3000, () => console.log('Server started'))

Output example

Server started

The code above will create an Express.js application that will listen for POST requests on the '/upload' route. The multer package is used to handle the file upload. The upload.single() method is used to upload a single file, and the file is stored in the uploads/ directory. The file is then sent in the response.

Code explanation

• const express = require('express');: This line imports the Express.js package.
• const app = express();: This line creates the Express.js application.
• const multer = require('multer');: This line imports the multer package.
• const upload = multer({dest: 'uploads/'});: This line configures multer to store the uploaded file in the uploads/ directory.
• app.post('/upload', upload.single('myFile'), (req, res, next) => {...}): This line listens for POST requests on the '/upload' route and uses the upload.single() method to upload a single file.
• res.send(file): This line sends the file in the response.

Helpful links

• Express.js
• Multer

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