Develop application using MEAN stack deployed on cloud

I am learning development on MEAN stack and will share the series of blogs which will hopefully help others.

Explain the project

I am developing a e-commerce solution for medical retail store which will be having following features:- 1) Product ordering
2) Product inventory update on delivery received. 3) Dashboard for store admin to see the stock inventory, alerts
for expiring products.

Technology used

• Node - package manager & web server
• Express framework - web framework to write Restful API 
• Mongo DB - Non relational database for persistence of data. Here we will be using cloud hosted mongo db
• Ionic framework - web application framework to develop web application and hybrid mobile application
• Heroku - cloud platform for hosting the application and API. 
• VS Code  - IDE to develop application
• Github - Source code repository to store code base.

In addition to this, I will be using additional framework, tools to support the application development.

Part 1 : Develop a Restful API using Nodejs using express framework

Let's start cracking with API development.

Setting up the environment

• Install Node js from https://nodejs.org
• Create a project folder 
• Open console on the project folder 
• Run command npm init, this will create a package.json file for further package tracking
• Install express framework with command npm install express --save. --save command will help in persisting the
  reference. This way I don't need to upload the packages on source control repository and it will be downloaded
  anywhere by npm install command. 

Setting up the node server

Create a server.js file on folder and write the below code:

var express = require("express");
var app = express();
app.set('port', (process.env.PORT || 5000));

This will setup express as app and setup the port. Then add the following code to start
the server.

//Setting up a server

var server= app.listen(app.get('port'), function() {
 var port= server.address().port;
 console.log("App is running on port",port);

});

   
Let's test if the application is running successfully by command npm start. You should
see the message logged "App is running on port". Let's write our first routes

app.get('/', function (req, res) {

  res.send('welcome to my API!');

});

On npm start command, we should see a page with welcome to my API message.

 

Now let's write our API end point. This is simple Get method for products API.

var productRouter = express.Router();

productRouter.route('/api/products')

.get(function (req, res) {

  Product.find(function (err, products) {

  if (err) {

    res.status(500).send(err);

    console.log(err);

}

  else { res.json('List of products'); }

});

});

Let's now connect this with mongo DB to get some real data.For this we will be using mongoose plug in which is similar to
entity framework in dotnet world. Let's install mongoose by running npm install mongoose --save.

Post that add the following code for mongoose. Make sure to change the mongo db connection string with the mongo db instance.
I have used mongodb cloud instance in this case on https://cloud.mongodb.com

var mongoose = require('mongoose'),

Schema = mongoose.Schema;

//Remember to change this

var db = mongoose.connect('mongodb://localhost:27017/medicineAPI');

//Schema definition

var productModel = new Schema({

 skuid: { type: String },

 name: { type: String },

 category: { type: String }

});

module.exports = mongoose.model('Product', productModel);

Let's change the API routing code to below.

productRouter.route('/products').get(function(req, res) {

Product.find(function (err, products) {

if (err) {

   res.status(500).send(err);

   console.log(err);

}

else {res.json(products);}

});

});

Let's add a POST method. To add this we need another plug in called body-parser to understand JSON body. The response status

in this case is 201 and it returns the saved object.

var bodyparser = require('body-parser');

// Body parser middleware

app.use(bodyparser.urlencoded({ extended: true }));

app.use(bodyparser.json());

productRouter.route('/products')

    .post(function (req, res) {

  var products =new Product(req.body);

  products.save();

  res.status(201).send(products);

  })

Now let's test the methods by using postman (a chrome plugin), you can use any other familiar tool as well.

URL: localhost:5000/api/products

POST Input json :-

{    "skuid": "f-1",     "name": "dolo",     "category": "fever" }

Our first API is ready with POST and GET methods. The final code is available at https://github.com/manibs/StoreManage

The next part will follow up which will contain deployment of this API to cloud and build web application.