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)

Data storage and asynchronous code


By definition, external data storage systems require asynchronous code in the Node.js architecture. The access time to retrieve data from disk, from another process, or from a database, always takes sufficient time to require deferred execution. 

The existing Notes data model is an in-memory data store. In theory, in-memory data access does not require asynchronous code and therefore, the existing model module could have used regular functions rather than async functions.

We knew that Notes must move to using databases, and would require an asynchronous API to access Notes data. For that reason, the existing Notes model API uses async functions so that in this chapter, we can persist Note data to databases.