In the tutorial, we’re gonna look at way to create NodeJs/Express RestAPIs with Post/Get/Put/Delete requests.
Related posts:
– How to setup Node/Express development environment
Overview
Demo
Goal
We create a NodeJs/Express RestAPIs project that has structure as below:
/nodejs-restapi /app /controllers customer.controller.js /routes customer.routes.js /node-modules package.json package-lock.json server.js
The project create a set of Rest-APIs for POST/GET/UPDATE/DELETE APIs:
/api/customers– GET all customers/api/customers/:id– GET a customer by Id'/api/customers– POST a customer/api/customers/update/:id– UPDATE a customer by Id/api/customers/delete/:id– DELETE a customer by Id
Setup NodeJs/Express project
Use NPM to create a Node/Express project as the guide
Create application directory
mkdir nodejs-restapi cd nodejs-restapi
Create package.json file
Use the npm init to create ‘package.json’ file:
nodejs-restapi>npm init
...
Press ^C at any time to quit.
package name: (nodejs-restapi)
version: (1.0.0)
description: NodeJs-RestApis
entry point: (index.js) server.js
test command:
git repository:
keywords: NodeJs-RestAPIs
author: JSA
license: (ISC)
About to write to C:\Users\pc\Desktop\nodejs\nodejs-restapi\package.json:
{
"name": "nodejs-restapi",
"version": "1.0.0",
"description": "NodeJs-RestApis",
"main": "server.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [
"NodeJs-RestAPIs"
],
"author": "JSA",
"license": "ISC"
}
Is this ok? (yes) yes
-> Check content of ‘package.json’ file:
{
"name": "nodejs-restapi",
"version": "1.0.0",
"description": "NodeJs-RestApis",
"main": "server.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [
"NodeJs-RestAPIs"
],
"author": "JSA",
"license": "ISC"
}
Install Express & Body-Parser
We need express and body-parse modules.
– Express is one of the most popular web frameworks for NodeJs which is built on top of Node.js http module, and adds support for routing, middleware, view system etc.
– Body-parser: parses/extract the body of an incoming HTTP request.
-> Installing them as commandline npm install express body-parser --save:
nodejs-restapi>npm install express body-parser --save npm notice created a lockfile as package-lock.json. You should commit this file. npm WARN nodejs-restapi@1.0.0 No repository field. + body-parser@1.18.2 + express@4.16.3 added 53 packages in 12.449s
Now see ‘package.json’ file:
{
"name": "nodejs-restapi",
"version": "1.0.0",
"description": "NodeJs-RestApis",
"main": "server.js",
"scripts": {
"test": "echo \"Error: no test specified\" && exit 1"
},
"keywords": [
"NodeJs-RestAPIs"
],
"author": "JSA",
"license": "ISC",
"dependencies": {
"body-parser": "^1.18.2",
"express": "^4.16.3"
}
}
Implement NodeJs/Express RestApis
Create server
In root folder ‘nodejs-restapi’, create a ‘server.js’ file:
var express = require('express');
var app = express();
var bodyParser = require('body-parser');
app.use(bodyParser.json())
require('./app/routes/customer.routes.js')(app);
// Create a Server
var server = app.listen(8081, function () {
var host = server.address().address
var port = server.address().port
console.log("App listening at http://%s:%s", host, port)
})
Implement Express Application
Routes
In root folder ‘nodejs-restapi’, create a router folder ‘/app/routes’. Then create a file ‘/app/routes/customer.routes.js’ for routing requests ‘GET/POST/DELETE/UPDATE’:
module.exports = function(app) {
var customers = require('../controllers/customer.controller.js');
// Create a new Customer
app.post('/api/customers', customers.create);
// Retrieve all Customer
app.get('/api/customers', customers.findAll);
// Retrieve a single Customer by Id
app.get('/api/customers/:id', customers.findOne);
// Update a Customer with Id
app.put('/api/customers/:id', customers.update);
// Delete a Customer with Id
app.delete('/api/customers/:id', customers.delete);
}
Controllers
In root folder ‘nodejs-restapi’, create a controller folder ‘/app/controllers’. Then create a file ‘/app/controllers/customer.controller.js’ that contains methods for executing above URL requests:
var customers = {
customer1: {
firstname: "Jack",
lastname: "Davis",
age: 25,
id: 1
},
customer2: {
firstname: "Mary",
lastname: "Taylor",
age: 37,
id: 2
},
customer3: {
firstname: "Peter",
lastname: "Thomas",
age: 17,
id: 3
},
customer4: {
firstname: "Peter",
lastname: "Thomas",
age: 17,
id: 4
}
}
exports.create = function(req, res) {
var newCustomer = req.body;
customers["customer" + newCustomer.id] = newCustomer;
console.log("--->After Post, customers:\n" + JSON.stringify(customers, null, 4));
res.end("Post Successfully: \n" + JSON.stringify(newCustomer, null, 4));
};
exports.findAll = function(req, res) {
console.log("--->Find All: \n" + JSON.stringify(customers, null, 4));
res.end("All Customers: \n" + JSON.stringify(customers, null, 4));
};
exports.findOne = function(req, res) {
var customer = customers["customer" + req.params.id];
console.log("--->Find customer: \n" + JSON.stringify(customer, null, 4));
res.end( "Find a Customer:\n" + JSON.stringify(customer, null, 4));
};
exports.update = function(req, res) {
var id = parseInt(req.params.id);
var updatedCustomer = req.body;
if(customers["customer" + id] != null){
// update data
customers["customer" + id] = updatedCustomer;
console.log("--->Update Successfully, customers: \n" + JSON.stringify(customers, null, 4))
// return
res.end("Update Successfully! \n" + JSON.stringify(updatedCustomer, null, 4));
}else{
res.end("Don't Exist Customer:\n:" + JSON.stringify(updatedCustomer, null, 4));
}
};
exports.delete = function(req, res) {
var deleteCustomer = customers["customer" + req.params.id];
delete customers["customer" + req.params.id];
console.log("--->After deletion, customer list:\n" + JSON.stringify(customers, null, 4) );
res.end( "Deleted customer: \n" + JSON.stringify(deleteCustomer, null, 4));
};
Now see again the project structure:
Test results
Run the NodeJs/Express project:
nodejs-restapi>node server.js App listening at http://:::8081
Use Postman to check result ->
– GET all customers:
– GET a customer by id:
– POST a customer:
– PUT a customer:
– DELETE a customer:
-> NodeJs/Express Logs:
App listening at http://:::8081
--->Find All:
{
"customer1": {
"firstname": "Jack",
"lastname": "Davis",
"age": 25,
"id": 1
},
"customer2": {
"firstname": "Mary",
"lastname": "Taylor",
"age": 37,
"id": 2
},
"customer3": {
"firstname": "Peter",
"lastname": "Thomas",
"age": 17,
"id": 3
},
"customer4": {
"firstname": "Peter",
"lastname": "Thomas",
"age": 17,
"id": 4
}
}
--->Find customer:
{
"firstname": "Peter",
"lastname": "Thomas",
"age": 17,
"id": 3
}
--->After Post, customers:
{
"customer1": {
"firstname": "Jack",
"lastname": "Davis",
"age": 25,
"id": 1
},
"customer2": {
"firstname": "Mary",
"lastname": "Taylor",
"age": 37,
"id": 2
},
"customer3": {
"firstname": "Peter",
"lastname": "Thomas",
"age": 17,
"id": 3
},
"customer4": {
"firstname": "Peter",
"lastname": "Thomas",
"age": 17,
"id": 4
},
"customer5": {
"firstname": "Adam",
"lastname": "Johnson",
"age": 48,
"id": 5
}
}
--->Update Successfully, customers:
{
"customer1": {
"firstname": "Jack",
"lastname": "Davis",
"age": 25,
"id": 1
},
"customer2": {
"firstname": "Mary",
"lastname": "Taylor",
"age": 37,
"id": 2
},
"customer3": {
"firstname": "Peter",
"lastname": "Thomas",
"age": 28,
"id": 3
},
"customer4": {
"firstname": "Peter",
"lastname": "Thomas",
"age": 17,
"id": 4
},
"customer5": {
"firstname": "Adam",
"lastname": "Johnson",
"age": 48,
"id": 5
}
}
--->After deletion, customer list:
{
"customer2": {
"firstname": "Mary",
"lastname": "Taylor",
"age": 37,
"id": 2
},
"customer3": {
"firstname": "Peter",
"lastname": "Thomas",
"age": 28,
"id": 3
},
"customer4": {
"firstname": "Peter",
"lastname": "Thomas",
"age": 17,
"id": 4
},
"customer5": {
"firstname": "Adam",
"lastname": "Johnson",
"age": 48,
"id": 5
}
}
