Book Image

Mastering JavaScript Object-Oriented Programming

Book Image

Mastering JavaScript Object-Oriented Programming

Overview of this book

ECMAScript 6 introduces several new Object-Oriented features that drastically change the way developers structure their projects. Web developers now have some advanced OOP functionality at their disposal to build large-scale applications in JavaScript. With this book, we'll provide you with a comprehensive overview of OOP principles in JavaScript and how they can be implemented to build sophisticated web applications. Kicking off with a subtle refresher on objects, we'll show you how easy it is to define objects with the new ES6 classes. From there, we'll fly you through some essential OOP principles, forming a base for you to get hands-on with encapsulation. You'll get to work with the different methods of inheritance and we'll show you how to avoid using inheritance with Duck Typing. From there, we'll move on to some advanced patterns for object creation and you'll get a strong idea of how to use interesting patterns to present data to users and to bind data. We'll use the famous promises to work with asynchronous processes and will give you some tips on how to organize your code effectively. You'll find out how to create robust code using SOLID principles and finally, we'll show you how to clearly define the goals of your application architecture to get better, smarter, and more effective coding. This book is your one-way ticket to becoming a JavaScript Jedi who can be counted on to deliver flexible and maintainable code.
Table of Contents (18 chapters)
Mastering JavaScript Object-Oriented Programming
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface

The Dependency Inversion Principle


The last SOLID principle concerns the dependence among the components of an application and states that:

1. High-level modules should not depend on low-level modules. Both should depend on abstractions.

2. Abstractions should not depend upon details. Details should depend on abstractions.

This is the Dependency Inversion Principle, and it consists of two recommendations. The first one concerns the classic layered architecture of an application, where in general the components of the high level are strictly dependent on the components at the low level. A possible modification to a low-level component may require a change to one or more high-level components. The first recommendation suggests to reverse this dependency, changing it toward an intermediate abstraction, such as an interface. So, a low-level component must implement an interface used by the components of the higher level.

The second recommendation says to make sure that the implementation details...