how to upload and read a file with nodejs / express - node.js

Question

there are all kinds of posts about this, but I'm still not getting it.
I want to upload a *.csv and read and process its contents.
my jade file is this
//views/import.jade
extends layout
block content
h1= title
form(action="/import", method="post", enctype="multipart/form-data")
input(type="file", name="ufile")
input(type="submit", name="Upload")
--
I changed the code, but req.files is undefined
//routes/index.js
/* import page. */
router.get('/blah', function(req, res, next) {
res.render('import', { title: 'Import Data' });
});
router.post('/import', function(req, res) {
console.log(req.files);
});
module.exports = router;

Answer 1

Convert the uploaded file in to string, using
toString('utf8')
you can than make any operation on string like convert it to json using csvtojson package
Here is the sample code for uploading csv and than convert to json-
/* csv to json */
const express = require("express"),
app = express(),
upload = require("express-fileupload"),
csvtojson = require("csvtojson");
let csvData = "test";
app.use(upload());
app.get("/", (req, res, next) => {
res.sendFile(__dirname + "/index.html");
});
app.post("/file", (req, res) => {
/** convert req buffer into csv string ,
* "csvfile" is the name of my file given at name attribute in input tag */
csvData = req.files.csvfile.data.toString('utf8');
return csvtojson().fromString(csvData).then(json =>
{return res.status(201).json({csv:csvData, json:json})})
});
app.listen(process.env.PORT || 4000, function(){
console.log('Your node js server is running');
});
working example- csvjsonapi

Answer 2

Hope this solves your question, this is my method to multiple upload file:
Nodejs :
router.post('/upload', function(req , res) {
var multiparty = require('multiparty');
var form = new multiparty.Form();
var fs = require('fs');
form.parse(req, function(err, fields, files) {
var imgArray = files.imatges;
for (var i = 0; i < imgArray.length; i++) {
var newPath = './public/uploads/'+fields.imgName+'/';
var singleImg = imgArray[i];
newPath+= singleImg.originalFilename;
readAndWriteFile(singleImg, newPath);
}
res.send("File uploaded to: " + newPath);
});
function readAndWriteFile(singleImg, newPath) {
fs.readFile(singleImg.path , function(err,data) {
fs.writeFile(newPath,data, function(err) {
if (err) console.log('ERRRRRR!! :'+err);
console.log('Fitxer: '+singleImg.originalFilename +' - '+ newPath);
})
})
}
})
Make sure your form tag has enctype="multipart/form-data" attribute.
I hope this gives you a hand ;)