Book Image

Mastering PHP Design Patterns

By : Junade Ali
Book Image

Mastering PHP Design Patterns

By: Junade Ali

Overview of this book

Design patterns are a clever way to solve common architectural issues that arise during software development. With an increase in demand for enhanced programming techniques and the versatile nature of PHP, a deep understanding of PHP design patterns is critical to achieve efficiency while coding. This comprehensive guide will show you how to achieve better organization structure over your code through learning common methodologies to solve architectural problems. You’ll also learn about the new functionalities that PHP 7 has to offer. Starting with a brief introduction to design patterns, you quickly dive deep into the three main architectural patterns: Creational, Behavioral, and Structural popularly known as the Gang of Four patterns. Over the course of the book, you will get a deep understanding of object creation mechanisms, advanced techniques that address issues concerned with linking objects together, and improved methods to access your code. You will also learn about Anti-Patterns and the best methodologies to adopt when building a PHP 7 application. With a concluding chapter on best practices, this book is a complete guide that will equip you to utilize design patterns in PHP 7 to achieve maximum productivity, ensuring an enhanced software development experience.
Table of Contents (14 chapters)
Mastering PHP Design Patterns
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface

Chain of Responsibility


Suppose we have a group of objects that together are meant to solve a problem. When one object can't solve a problem, we want the object to send the task to a different object in a given chain. This is what the Chain of Responsibility design pattern is used for.

In order to get this to work, we need a handler, which will be our Chain interface. The various objects in the chain will all implement this Chain interface.

Let's start with a simple example; an associate can purchase an asset for less than $100, a manager can purchase something for less than $500.

Our abstraction for the Purchaser interface looks like this:

<?php 
 
interface Purchaser 
{ 
  public function setNextPurchaser(Purchaser $nextPurchaser): bool; 
 
  public function buy($price): bool; 
} 

Our first implementation is the Associate class. Quite simply, we implement the setNextPurchaser function so that it will set the nextPurchaser class property to the next...