In how to upload a file using Fetch I explained how to upload a file to a server using Fetch.
In this post I’m going to show you part 2: how to use Node.js, and in particular Express, to handle uploaded files.
Install the express-fileupload npm module:
npm install express-fileuploadand add it to your middleware:
import fileupload from 'express-fileupload'
//or
const fileupload = require('express-fileupload')
After you created your Express app, add:
app.use(
fileupload(),
//...
This is needed because otherwise the server can’t parse file uploads.
Now uploaded files are provided in req.files. If you forget to add that middleware, req.files would be undefined.
app.post('/saveImage', (req, res) => {
const image = req.files.myFile
const path = __dirname + '/images/' + image.name
image.mv(path, (error) => {
if (error) {
console.error(error)
res.writeHead(500, {
'Content-Type': 'application/json'
})
res.end(JSON.stringify({ status: 'error', message: error }))
return
}
res.writeHead(200, {
'Content-Type': 'application/json'
})
res.end(JSON.stringify({ status: 'success', path: '/images/' + image.name }))
})
})
This is the smallest amount of code needed to handle files.
We call the mv property of the uploaded image. That is provided to us by the express-fileupload module. We move it to path and then we communicate the success (or an error!) back to the client.
Download my free Node.js Handbook and check out my Node.js Course!