server.js

var http = require('http');
var fs = require('fs');
var path = require('path');
var util = require('util');
var formidable = require('formidable');

http.createServer(function(req, res) { // request, response
    console.log( 'Req method: ' + req.method + ' , URL: ' + req.url );

    //-----------------------//-------------------------------------------------------------------------------------
    //--- UPLOAD handling ---//
    //-----------------------//
    if (req.url == '/upload' && req.method.toLowerCase() == 'post') {
        var form = new formidable.IncomingForm();

        form.parse(req, function(err, fields, files) {
            if (err) throw err;

            fs.readFile( files.filepath.path, function (err, data) {
                if (err) throw err;

                var fileName = files.filepath.name;
                fs.writeFile( __dirname + '/uploadedFiles/' + fileName, data, function (err) {
                    if (err) throw err;

                    //-----------------------------------------------//---------------------------------------------
                    //--- LOAD and APPEND external JSON file with ---//
                    //--- data from request                       ---//
                    //-----------------------------------------------//
                    var jsonObj = require('./storedFilesList.json');

                    jsonObj[fileName] = {size:files.filepath.size, expDate:'-', path:__dirname + '/uploadedFiles/' + fileName};

                    var jsonString = JSON.stringify(jsonObj); // convert JSON obj to String

                    fs.writeFile('storedFilesList.json', jsonString, function(err){
                        if (err) throw err;
                        console.log('File ' + fileName + ' was succesfully written to JSON ext file.');
                    });

                    console.log('File ' + fileName + ' was succesfully saved.');
                });
            });

            res.writeHead(200, {'content-type': 'text/plain'});
            res.write('OK');
            res.end( util.inspect({fields: fields, files: files}) );
        });

        return;
    }

    //-----------------------//-------------------------------------------------------------------------------------
    //--- DELETE handling ---//
    //-----------------------//
    if (req.url == '/delete' && req.method.toLowerCase() == 'post') {

        var form = new formidable.IncomingForm();
        form.parse(req, function(err, a, b) {
            if (err) throw err;
            console.log('a: ' + a + ' b: ' + b);
        });


    }

    //---------------------------//---------------------------------------------------------------------------------
    //--- Source code loading ---//
    //---------------------------//
    var filePath = '.' + req.url;
    if (filePath == './')
        filePath = './index.html';
    if (filePath.indexOf('/../') !== -1) {
        res.writeHead(400);
        res.end();
    } else {
        var extname = path.extname(filePath);
        var contentType = 'text/plain';
        switch (extname) {
            case '.js': contentType = 'text/javascript'; break;
            case '.html': contentType = 'text/html'; break;
            case '.css': contentType = 'text/css'; break;
            case '.svg': contentType = 'image/svg+xml'; break;
            case '.json': contentType = 'application/json'; break;
        }
        fs.exists(filePath, function(exists) {
            if (exists) {
                fs.readFile(filePath, function(error, content) {
                    if (error) {
                        res.writeHead(500);
                        res.end();
                    } else {
                        res.writeHead(200, { 'Content-Type': contentType });
                        res.write(content, 'utf-8');
                        res.end();
                    }
                });
            } else {
                res.writeHead(404);
                res.end();
            }
        });
    }

}).listen(8123);

console.log('Server running at http://127.0.0.1:8123/');