Book Image

Node.js Web Development. - Fourth Edition

By : David Herron
Book Image

Node.js Web Development. - Fourth Edition

By: David Herron

Overview of this book

Node.js is a server-side JavaScript platform using an event-driven, non-blocking I/O model allowing users to build fast and scalable data-intensive applications running in real time. This book gives you an excellent starting point, bringing you straight to the heart of developing web applications with Node.js. You will progress from a rudimentary knowledge of JavaScript and server-side development to being able to create, maintain, deploy and test your own Node.js application.You will understand the importance of transitioning to functions that return Promise objects, and the difference between fs, fs/promises and fs-extra. With this book you'll learn how to use the HTTP Server and Client objects, data storage with both SQL and MongoDB databases, real-time applications with Socket.IO, mobile-first theming with Bootstrap, microservice deployment with Docker, authenticating against third-party services using OAuth, and use some well known tools to beef up security of Express 4.16 applications.
Table of Contents (19 chapters)
Title Page
Dedication
Packt Upsell
Contributors
Preface
Index

Calling a REST backend service from an Express application


Now that we've seen how to make HTTP client requests, we can look at how to make a REST query inside an Express web application. What that effectively means is to make an HTTP GET request to a backend server, which responds with the Fibonacci number represented by the URL. To do so, we'll refactor the Fibonacci application to make a Fibonacci server that is called from the application. While this is overkill for calculating Fibonacci numbers, it lets us look at the basics of implementing a multitier application stack in Express.

Inherently, calling a REST service is an asynchronous operation. That means calling the REST service will involve a function call to initiate the request and a callback function to receive the response. REST services are accessed over HTTP, so we'll use the HTTP client object to do so.

Implementing a simple REST server with Express

While Express has a powerful templating system, making it suitable for delivering...