Mastering JavaScript Design Patterns - Second Edition

Simon Timms

• Publisher: Packt Publishing
• Year: 2016
• eBook ISBN: 9781785880353
• Edition: 2
• Topic: Computer Science
• Subtopic: Programming in JavaScript
• Index: Computer Science

Write reliable code to create powerful applications by mastering advanced JavaScript design patternsAbout This Book• Learn how to use tried and true software design methodologies to enhance your JavaScript code• Discover robust JavaScript implementations of classic and advanced design patterns• Packed with easy-to-follow examples that can be used to create reusable code and extensible designsWho This Book Is ForThis book is ideal for JavaScript developers who want to gain expertise in object-oriented programming with JavaScript and the new capabilities of ES-2015 to improve their web development skills and build professional-quality web applications.What You Will Learn• Harness the power of patterns for tasks ranging from application building to code testing• Rethink and revitalize your code with the use of functional patterns• Improve the way you organize your code• Build large-scale apps seamlessly with the help of reactive patterns• Identify the best use cases for microservices• Get to grips with creational, behavioral, and structural design patterns• Explore advanced design patterns including dependency injectionIn DetailWith the recent release of ES-2015, there are several new object-oriented features and functions introduced in JavaScript. These new features enhance the capabilities of JavaScript to utilize design patterns and software design methodologies to write powerful code.Through this book, you will explore how design patterns can help you improve and organize your JavaScript code. You'll get to grips with creational, structural and behavioral patterns as you discover how to put them to work in different scenarios. Then, you'll get a deeper look at patterns used in functional programming, as well as model view patterns and patterns to build web applications.This updated edition will also delve into reactive design patterns and microservices as they are a growing phenomenon in the world of web development. You will also find patterns to improve the testability of your code using mock objects, mocking frameworks, and monkey patching. We'll also show you some advanced patterns including dependency injection and live post processing.By the end of the book, you'll be saved of a lot of trial and error and developmental headaches, and you will be on the road to becoming a JavaScript expert.Style and approachPacked with several real-world use cases, this book shows you through step-by-step instructions how to implement the advanced object-oriented programming features to build sophisticated web applications that promote scalability and reusability.

Mastering JavaScript Design Patterns Second Edition

---

Table of Contents

Mastering JavaScript Design Patterns Second Edition

Credits

About the Author

About the Reviewer

www.PacktPub.com

eBooks, discount offers, and more

Why subscribe?

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. Designing for Fun and Profit

The road to JavaScript

The early days

A pause

The way of GMail

JavaScript everywhere

What is a design pattern?

Anti-patterns

Summary

I. Classical Design Patterns

2. Organizing Code

Chunks of code

What's the matter with global scope anyway?

Objects in JavaScript

Build me a prototype

Inheritance

Modules

ECMAScript 2015 classes and modules

Best practices and troubleshooting

Summary

3. Creational Patterns

Abstract factory

Implementation

Builder

Implementation

Factory method

Implementation

Singleton

Implementation

Disadvantages

Prototype

Implementation

Tips and tricks

Summary

4. Structural Patterns

Adapter

Implementation

Bridge

Implementation

Composite

Example

Implementation

Decorator

Implementation

Façade

Implementation

Flyweight

Implementation

Proxy

Implementation

Hints and tips

Summary

5. Behavioral Patterns

Chain of responsibility

Implementation

Command

Command message

Invoker

Receiver

Interpreter

Example

Implementation

Iterator

Implementation

ECMAScript 2015 iterators

Mediator

Implementation

Memento

Implementation

Observer

Implementation

State

Implementation

Strategy

Implementation

Template method

Implementation

Visitor

Hints and tips

Summary

II. Other Patterns

6. Functional Programming

Functional functions are side-effect-free

Function passing

Implementation

Filters and pipes

Implementation

Accumulators

Implementation

Memoization

Implementation

Immutability

Lazy instantiation

Implementation

Hints and tips

Summary

7. Reactive Programming

Application state changes

Streams

Filtering streams

Merging streams

Streams for multiplexing

Hints and tips

Summary

8. Application Patterns

First, some history

Model View Controller

MVC code

Model View Presenter

MVP code

Model View ViewModel

MVVM code

A better way to transfer changes between the model and the view

Observing view changes

Tips and tricks

Summary

9. Web Patterns

Sending JavaScript

Combining files

Minification

Content Delivery Networks

Plugins

jQuery

d3

Doing two things at once – multithreading

Circuit breaker pattern

Back-off

Degraded application behavior

Promise pattern

Hints and tips

Summary

10. Messaging Patterns

What's a message anyway?

Commands

Events

Request-reply

Publish-subscribe

Fan out and in

Dead letter queues

Message replay

Pipes and filters

Versioning messages

Hints and tips

Summary

11. Microservices

Façade

Service selector

Aggregate services

Pipeline

Message upgrader

Failure patterns

Service degradation

Message storage

Message replay

Indempotence of message handling

Hints and tips

Summary

12. Patterns for Testing

The testing pyramid

Testing in the small with unit tests

Arrange-Act-Assert

Assert

Fake objects

Test spies

Stubs

Mock

Monkey patching

Interacting with the user interface

Browser testing

Faking the DOM

Wrapping the manipulation

Tips and tricks

Summary

13. Advanced Patterns

Dependency injection

Live post processing

Aspect oriented programming

Mixins

Macros

Tips and tricks

Summary

14. ECMAScript-2015/2016 Solutions Today

TypeScript

Decorators

Async/Await

Typing

BabelJS

Classes

Default parameters

Template literals

Block bindings with let

In production

Tips and tricks

Summary

Index

Mastering JavaScript Design Patterns Second Edition

Copyright © 2016 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: November 2014

Second published: June 2016

Production reference: 1240616

Published by Packt Publishing Ltd.

Livery Place

35 Livery Street

Birmingham B3 2PB, UK.

ISBN 978-1-78588-216-6

www.packtpub.com

Credits

Author

Simon Timms

Reviewer

Dobrin Ganev

Commissioning Editor

Wilson D'souza

Acquisition Editor

Tushar Gupta

Content Development Editor

Onkar Wani

Technical Editor

Dhiraj Chandanshive

Copy Editor

Safis Editing

Project Coordinator

Ulhas Kambli

Proofreader

Safis Editing

Indexer

Monica Ajmera Mehta

Production Coordinator

Aparna Bhagat

Cover Work

Aparna Bhagat

About the Author

Simon Timms is a developer who loves writing code. He writes in a variety of languages and using a number of tools. Mostly, he develops web applications with .NET backends. Simon is very interested in visualizations and cloud computing. A background in builds and system administration keeps him on the straight and narrow when it comes to DevOps.

He is the author of Social Data Visualization with HTML5 and JavaScript, Packt Publishing. He blogs on blog.simontimms.com, and he is also a frequent contributor to the Western Devs (http://westerndevs.com), which is a loose collaboration of developers mostly located in Canada. Twice a week, he participates in a videocast called The ASP.NET Monsters about the future of ASP.NET, which is one of the most popular series on Microsoft's Channel 9 video service (https://channel9.msdn.com/Series/aspnetmonsters).

Simon is the president of the Calgary .Net user group and a member of half a dozen other groups. He speaks on a variety of topics from DevOps to how the telephone system works. He works as a principal software developer for Clear-Measure located in Austin, Texas. He is currently working on a new title about ASP.NET Core.

I would like to thank my wonderful wife for all her support and my kids for providing a welcome distraction from writing. I would also like to thank the Western Devs for being a constant sounding board for insane ideas.

About the Reviewer

Dobrin Ganev is a software developer with years of experience in various development environments from finance to business process management. In recent years, he has focused on geospatial development and data analytics using languages such as JavaScript, Java, Python, Scala, and R. He has extensive knowledge about the open source geospatial and the Esri platforms. Currently, he is focused on Big Data, and its applications across broad industries and sectors.

chorStream Inc. (http://www.chorstream.com/) is a software development firm focused on the use of Big Data and Big Data technologies to help clients work with and leverage large and diverse volumes of data, which was founded in 2015. As a co-founder, Mr. Ganev has worked with an accomplished team of professionals to create and bring to market an application's framework that end users are able to use to build custom and focused applications without needing any development skills.

He has reviewed the book ArcGIS for JavaScript Developers by Example, by Packt Publishing.

www.PacktPub.com

eBooks, discount offers, and more

Did you know that Packt offers eBook versions of every book published, with PDF and ePub files available? You can upgrade to the eBook version at www.PacktPub.com and as a print book customer, you are entitled to a discount on the eBook copy. Get in touch with us at <[email protected]> for more details.

At www.PacktPub.com, you can also read a collection of free technical articles, sign up for a range of free newsletters and receive exclusive discounts and offers on Packt books and eBooks.

https://www2.packtpub.com/books/subscription/packtlib

Do you need instant solutions to your IT questions? PacktLib is Packt's online digital book library. Here, you can search, access, and read Packt's entire library of books.

Why subscribe?

• Fully searchable across every book published by Packt
• Copy and paste, print, and bookmark content
• On demand and accessible via a web browser

Preface

JavaScript is starting to become one of the most popular languages in the world. However, its history as a bit of a toy language means that developers are tempted to ignore good design. Design patterns are a great tool to suggest some well-tried solutions.

What this book covers

This book is divided into two main halves, each of which contains a number of chapters....

Table of contents

• Mastering JavaScript Design Patterns Second Edition