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

Cross-cutting features and AOP


When we introduced the SOLID principles in Chapter 11, SOLID Principles, we discussed the Single Responsibility Principle. Based on this principle, a component must be focused on a single responsibility, that is, it has to implement the features that concern only a single aspect of the application. Often, however, in a complex application, we need cross-cutting features that can be intrusive and forced to enter in a component some code that is not strictly correlated with its specific goal. These features include, the following:

  • Error handling

  • Logging and tracing

  • Authorization control

  • Transaction control

These and other features are usually included in any application, but in most cases, they tend to pollute the code introducing unrelated logic.

The log management example

Let's analyze this problem with an example. Suppose we have a constructor function for objects having a method that makes the sum of two numbers:

function Calculator() {} 
 
Calculator.prototype...