How to do csv file export and download on request [duplicate] - node.js

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()

Answer 3

For static files like pdfs, Word docs, etc. just use Express's static function in your config:
// Express config
var app = express().configure(function () {
this.use('/public', express.static('public')); // <-- This right here
});
And then just put all your files inside that 'public' folder, for example:
/public/docs/my_word_doc.docx
And then a regular old link will allow the user to download it:
My Word Doc

Answer 4

Here's how I do it:
create file
send file to client
remove file
Code:
let fs = require('fs');
let path = require('path');
let myController = (req, res) => {
let filename = 'myFile.ext';
let absPath = path.join(__dirname, '/my_files/', filename);
let relPath = path.join('./my_files', filename); // path relative to server root
fs.writeFile(relPath, 'File content', (err) => {
if (err) {
console.log(err);
}
res.download(absPath, (err) => {
if (err) {
console.log(err);
}
fs.unlink(relPath, (err) => {
if (err) {
console.log(err);
}
console.log('FILE [' + filename + '] REMOVED!');
});
});
});
};

Answer 5

In Express 4.x, there is an attachment() method to Response:
res.attachment();
// Content-Disposition: attachment
res.attachment('path/to/logo.png');
// Content-Disposition: attachment; filename="logo.png"
// Content-Type: image/png

Answer 6

'use strict';
var express = require('express');
var fs = require('fs');
var compress = require('compression');
var bodyParser = require('body-parser');
var app = express();
app.set('port', 9999);
app.use(bodyParser.json({ limit: '1mb' }));
app.use(compress());
app.use(function (req, res, next) {
req.setTimeout(3600000)
res.header('Access-Control-Allow-Origin', '*');
res.header('Access-Control-Allow-Headers', 'Origin, X-Requested-With, Content-Type, Accept,' + Object.keys(req.headers).join());
if (req.method === 'OPTIONS') {
res.write(':)');
res.end();
} else next();
});
function readApp(req,res) {
var file = req.originalUrl == "/read-android" ? "Android.apk" : "Ios.ipa",
filePath = "/home/sony/Documents/docs/";
fs.exists(filePath, function(exists){
if (exists) {
res.writeHead(200, {
"Content-Type": "application/octet-stream",
"Content-Disposition" : "attachment; filename=" + file});
fs.createReadStream(filePath + file).pipe(res);
} else {
res.writeHead(400, {"Content-Type": "text/plain"});
res.end("ERROR File does NOT Exists.ipa");
}
});
}
app.get('/read-android', function(req, res) {
var u = {"originalUrl":req.originalUrl};
readApp(u,res)
});
app.get('/read-ios', function(req, res) {
var u = {"originalUrl":req.originalUrl};
readApp(u,res)
});
var server = app.listen(app.get('port'), function() {
console.log('Express server listening on port ' + server.address().port);
});

Answer 7

you can use res.sendFile()... the Sample-download.xlsx should be in the same directory as this function.
const downloadFile = (req,res) => {
var options = {
root: path.join(__dirname),
};
let fileName = "Sample-download.xlsx";
res.sendFile(fileName, options, function (err) {
if (err) {
console.log(err);
return res.status(500).json({ success: false, message: "internal server error. please try again later" });
} else {
console.log("Sent:", fileName, "at", new Date().toString());
}
});
}