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 (14 chapters)

Promises, async functions, and Express router functions

Before we get into developing our application, we must take a deeper look at a pair of new ES-2015/2016/2017 features that collectively revolutionize JavaScript programming:  The Promise class and async functions. Both are used for deferred and asynchronous computation and can make intensely nested callback functions a thing of the past:

  • A Promise represents an operation that hasn't completed yet but is expected to be completed in the future. We've seen Promises in use. The .then or .catch functions are invoked when the promised result (or error) is available. 
  • Generator functions are a new kind of function that can be paused and resumed, and can return results from the middle of the function. 
  • Those two features were mixed with another, the iteration protocol, along with some new syntax, to...