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.
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