10 Table of Contents

The Solution ......................................................... 53

Sample Code ........................................................ 54

Adding a Little Color ................................................. 57

Factories to Hide Object State Setup ................................... 61

Factories to Promote Polymorphism ................................... 63

Factories for Lazy Loading ............................................ 71

Issues ............................................................... 72

4 The Singleton Pattern ........................ 75

The Problem ........................................................ 75

The Solution ......................................................... 76

Sample Code ........................................................ 77

A “Global” Approach ................................................. 77

A Static Approach .................................................... 79

The Singleton in PHP5 ................................................ 80

Issues ............................................................... 81

The Monostate Pattern: Stealth Singletons .............................. 81

5 The Registry Pattern ......................... 85

The Problem ........................................................ 85

The Solution ......................................................... 85

Sample Code ........................................................ 86

An Example ......................................................... 90

Implementing the Registry as a MonoState Object ....................... 92

Implementing with Class Static Variables ............................... 95

Issues ............................................................... 98

Embedded Registry .................................................. 98

6 The MockObject Pattern ..................... 101

The Problem ....................................................... 101

The Solution ....................................................... 102

Sample Code ....................................................... 102

A Legacy Application ................................................ 106

Issues .............................................................. 119

Resources .......................................................... 120