Download a file from NodeJS Server using Express

Question

How can I download a file that is in my server to my machine accessing a page in a nodeJS server?

I'm using the ExpressJS and I've been trying this:

app.get('/download', function(req, res){    var file = fs.readFileSync(__dirname + '/upload-folder/dramaticpenguin.MOV', 'binary');    res.setHeader('Content-Length', file.length);   res.write(file, 'binary');   res.end(); }); 

But I can't get the file name and the file type ( or extension ). Can anyone help me with that?

Answer 1

Update

Express has a helper for this to make life easier.

app.get('/download', function(req, res){   const file = `${__dirname}/upload-folder/dramaticpenguin.MOV`;   res.download(file); // Set disposition and send it. }); 

Old Answer

As far as your browser is concerned, the file's name is just 'download', so you need to give it more info by using another HTTP header.

res.setHeader('Content-disposition', 'attachment; filename=dramaticpenguin.MOV'); 

You may also want to send a mime-type such as this:

res.setHeader('Content-type', 'video/quicktime'); 

If you want something more in-depth, here ya go.

var path = require('path'); var mime = require('mime'); var fs = require('fs');  app.get('/download', function(req, res){    var file = __dirname + '/upload-folder/dramaticpenguin.MOV';    var filename = path.basename(file);   var mimetype = mime.lookup(file);    res.setHeader('Content-disposition', 'attachment; filename=' + filename);   res.setHeader('Content-type', mimetype);    var filestream = fs.createReadStream(file);   filestream.pipe(res); }); 

You can set the header value to whatever you like. In this case, I am using a mime-type library - node-mime, to check what the mime-type of the file is.

Another important thing to note here is that I have changed your code to use a readStream. This is a much better way to do things because using any method with 'Sync' in the name is frowned upon because node is meant to be asynchronous.

Answer 2

Use res.download()

It transfers the file at path as an “attachment”. For instance:

var express = require('express'); var router = express.Router();  // ...  router.get('/:id/download', function (req, res, next) {     var filePath = "/my/file/path/..."; // Or format the path using the `id` rest param     var fileName = "report.pdf"; // The default name the browser will use      res.download(filePath, fileName);     }); 

• Read more about res.download()