How to Create NodeJS Application without view ? Only NodeJS REST API

For an example see the code in this answer:

• Node.js send data to backend with AJAX

Stripping all unnecessary code it would be basically:

const express = require('express');
const bodyParser = require('body-parser');

const app = express();
app.use(bodyParser.json());

app.post('/email', (req, res) => {
  console.log(req.body.address);
  res.json({ ok: true });
});

app.listen(4443, () => console.log('Listening on http://localhost:4443/'));

This code is a very simple REST API that exposes one endpoint but you can easily add more.

But if you're building a RESTful API from scratch then you can consider using some other frameworks like: Hapi, Restify, LoopBack, and other frameworks listed on http://nodeframework.com/ - Express is a very solid but fairly minimal framework and it's not the only option out there.

Yes you can. express is capable to return response other that html element.

However, I would recommend you to use swagger project in developing REST API via express. The project will surely come in handy when developing and MAINTAINING API, especially if your API is huge and complex (lots of url and operation).

This site has a good explanation on how to install, use and run the swagger in NodeJs.

You can do this with express - see below

Install express and body-parser, feel free to use the module below

var express = require('express');
var app = express();
var bodyParser = require('body-parser');

module.exports = {
    init: function(module_Enabled){
        var portnum = 1234;    process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0";

        var allowCrossDomain = function(req,÷ res, next) {
            res.header('Access-Control-Allow-Origin', '*');
            res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE,OPTIONS');
            res.header('Access-Control-Allow-Headers', 'Content-Type, Authorization, Content-Length, X-Requested-With');

            // intercept OPTIONS method
            if ('OPTIONS' == req.method) {
                res.send(200);
            } else {
                next();
            }
        };
        app.use(bodyParser.urlencoded({
            extended: false
        }));
        app.use(bodyParser.json());
        app.use(allowCrossDomain);
        var server = app.listen(portnum, function() {
            var host = server.address().address;
            var port = server.address().port;
            console.log("Content Provider Service listening at http://%s:%s", host, port);
        });
        app.get('/', function(req, res) {
            res.send('data');
        });
    }
}