excel uploader/parser

app.js

const express = require('express')
const app = express()
const router = express.Router();
const multer  = require('multer')
const upload = multer({ dest: 'uploads/' })
const Parse = require('csv-parse');
const fs = require('fs');

app.use(express.static(__dirname + '/'));
function parseCSVFile(sourceFilePath, columns, onNewRecord, handleError, done){
    var source = fs.createReadStream(sourceFilePath);

    var linesRead = 0;

    var parser = Parse({
        delimiter: ',',
        columns:columns
    });

    parser.on("readable", function(){
        var record;
        while (record = parser.read()) {
            linesRead++;
            onNewRecord(record);
        }
    });

    parser.on("error", function(error){
        handleError(error)
    });

    parser.on("end", function(){
        done(linesRead);
    });

    source.pipe(parser);
}

//We will call this once Multer's middleware processed the request
//and stored file in req.files.fileFormFieldName

function parseFile(req, res, next){
    var filePath = req.file.path;
    console.log(filePath);
    function onNewRecord(record){
        console.log(record)
    }

    function onError(error){
        console.log(error)
    }

    function done(linesRead){
        res.send(200, linesRead)
    }

    var columns = true;
    parseCSVFile(filePath, columns, onNewRecord, onError, done);

}

//this is the route handler with two middlewares.
//First:  Multer middleware to download file. At some point,
//this middleware calls next() so process continues on to next middleware
//Second: use the file as you need
app.post('/upload', upload.single('uploadArea'), parseFile);

app.listen(3000, function () {
  console.log('... localhost:3000 !')
})