app.js

const { MongoClient } = require('mongodb');
const{ ObjectId } = require('mongodb').ObjectId;
const express = require('express');
const path = require('path');
const bodyParser = require("body-parser");
const app = express();
const port = 3000;

async function main() {
    /**
     * Connection URI. Update <username>, <password>, and <your-cluster-url> to reflect your cluster.
     * See https://docs.mongodb.com/ecosystem/drivers/node/ for more details
     */

	const uri = "mongodb://127.0.0.1:27017/eventsList";
	const client = new MongoClient(uri, {
		useUnifiedTopology: true,
		useNewUrlParser: true,
	});
	try {
		// Connect to the MongoDB cluster
		await client.connect();
		// Make the appropriate DB calls
		await init(client);

	} catch (e) {
		console.error(e);
	}
}
main().catch(console.err);


async function init(client) {
	app.use(express.static(path.join(__dirname, 'public')));
	app.use(bodyParser.json());
	app.use(bodyParser.urlencoded({ extended: true })); //extended:true to encode objects and arrays  https://github.com/expressjs/body-parser#bodyparserurlencodedoptions

	const db = client.db('eventList')
	const events = db.collection('events')

	app.get('/init', function (req, res) {
		events.insertOne({
			text: "Some Helpful event",
			start_date: new Date(2018, 8, 1),
			end_date: new Date(2018, 8, 5)
		})
		events.insertOne({
			text: "Another Cool Event",
			start_date: new Date(2018, 8, 11),
			end_date: new Date(2018, 8, 11)
		})
		events.insertOne({
			text: "Super Activity",
			start_date: new Date(2018, 8, 9),
			end_date: new Date(2018, 8, 10)
		})
		res.send("Test events were added to the database")
	});

	app.get('/data', function (req, res) {
		events.find().toArray(function (err, data) {
			//set the id property for all client records to the database records, which are stored in ._id field
			for (var i = 0; i < data.length; i++){
				data[i].id = data[i]._id;
				delete data[i]["!nativeeditor_status"];
			}
			//output response
			res.send(data);
		});
	});


	// Routes HTTP POST requests to the specified path with the specified callback functions. For more information, see the routing guide.
	// http://expressjs.com/en/guide/routing.html

	app.post('/data', function (req, res) {
		var data = req.body;
		var mode = data["!nativeeditor_status"];
		var sid = data.id;
		var tid = sid;

		function update_response(err) {
			if (err)
				mode = "error";
			else if (mode == "inserted"){
				tid = data._id;
			}
			res.setHeader("Content-Type", "application/json");
			res.send({ action: mode, sid: sid, tid: String(tid) });
		}

		if (mode == "updated") {
			events.updateOne({"_id": ObjectId(tid)}, {$set: data}, update_response);
		} else if (mode == "inserted") {
			events.insertOne(data, update_response);
		} else if (mode == "deleted") {
			events.deleteOne({"_id": ObjectId(tid)}, update_response)
		} else
			res.send("Not supported operation");
	});
};

// Binds listens for connections on the specified host and port. This method is identical to Node’s http.Server.listen().
app.listen(port, () => {
	console.log("Server is running on port " + port + "...");
});