Book Image

Mastering Node.js - Second Edition

By : Sandro Pasquali, Kevin Faaborg
Book Image

Mastering Node.js - Second Edition

By: Sandro Pasquali, Kevin Faaborg

Overview of this book

Node.js, a modern development environment that enables developers to write server- and client-side code with JavaScript, thus becoming a popular choice among developers. This book covers the features of Node that are especially helpful to developers creating highly concurrent real-time applications. It takes you on a tour of Node's innovative event non-blocking design, showing you how to build professional applications. This edition has been updated to cover the latest features of Node 9 and ES6. All code examples and demo applications have been completely rewritten using the latest techniques, introducing Promises, functional programming, async/await, and other cutting-edge patterns for writing JavaScript code. Learn how to use microservices to simplify the design and composition of distributed systems. From building serverless cloud functions to native C++ plugins, from chatbots to massively scalable SMS-driven applications, you'll be prepared for building the next generation of distributed software. By the end of this book, you'll be building better Node applications more quickly, with less code and more power, and know how to run them at scale in production environments.
Table of Contents (13 chapters)

Working with headers

Each HTTP request made to a Node server will likely contain useful header information, and clients normally expect to receive similar package information from a server. Node provides straightforward interfaces for reading and writing headers. We'll briefly go over those simple interfaces, clarifying some details. Finally, we'll discuss how more advanced header usage might be implemented in Node, studying some common network responsibilities a Node server will likely need to accommodate.

A typical request header will look something like the following:

Headers are simple key/value pairs. Request keys are always lowercased. You may use any case format when setting response keys.

Reading headers is straightforward. Read header information by examining the request.header object, which is a 1:1 mapping of the header's key/value pairs. To fetch the...