this print for content only—size & color not accurate CYAN MAGENTA YELLOW BLACK PANTONE 123 C BOOKS FOR PROFESSIONALS BY PROFESSIONALS ® Matt Zandstra, Author of Sams Teach Yourself PHP in 24 Hours US $44.99 Shelve in: PHP User level: Intermediate www.apress.com SOURCE CODE ONLINE Companion eBook See last page for details on $10 eBook version ISBN 978-1-4302-2925-4 9 781430 229254 5 44 9 9 PHP Objects, Patterns, and Practice THIRD EDITION Dear Reader, Over the past decade, PHP has embraced the object-oriented revolution. The language itself, the developers who work with it, and the applications they build, all increasingly share a focus on objects and object-oriented design. Another movement, separate but related, has taken root as well. That is the use of tools and techniques that help to ensure the success of projects, the efficacy of teams, and the quality of code. You’ll begin with an overview of PHP's object-oriented features, introducing key topics like class declaration, object instantiation, inheritance, and method and property encapsulation. You'll also learn about advanced topics including static methods and properties, abstract classes, interfaces, exception handling, object cloning, namespaces, closures and more. The next part of this book is devoted to design patterns, a vocabulary for applying elegant solutions to common problems in software development. You’ll learn about pattern concepts and discover how to implement several key pat- terns in your PHP applications. You’ll also find chapters on enterprise and data- base patterns. In the last section of this book, you will find practices and tools for managing your codebase and for collaborating with others in development. These include Phing, PHPUnit, phpDocumentor, PEAR, and Subversion. You’ll also learn how to use Continuous Integration, a system that brings all these tools together and automates them. I wrote PHP Objects, Patterns, and Practice to provide the kind of overview of code design and project practice I wish had been available when I first started to develop serious PHP applications. I hope this book inspires pleasure in coding and teaches you to build systems that are elegant in both design and management. Matt Zandstra THE APRESS ROADMAP Pro PHP: Patterns, Frameworks, Testing, and More PHP Objects, Patterns, and Practice, Third Edition Pro PHP Refactoring with Test Driven Design PHP Object-Oriented Solutions Pro PHP and jQuery Practical Web 2.0 Applications with PHP PHP for Absolute Beginners Beginning PHP and MySQL, Third Edition Zandstra Companion eBook Available PHP Objects, Patterns, and Practice 7.5 x 9.25 spine = 1.000" 536 page count THE EXPERT’S VOICE ® IN OPEN SOURCE THIRD EDITION Matt Zandstra Build powerful code by mastering PHP’s object-oriented enhancements, design patterns, and essential development tools THIRD EDITION PHP Objects, Patterns, and Practice i PHP Objects, Patterns, and Practice Third Edition ■ ■ ■ Matt Zandstra ii PHP Objects, Patterns, and Practice, Third Edition Copyright © 2010 by Matt Zandstra All rights reserved. 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You will need to answer questions pertaining to this book in order to successfully download the code. iii Contents at a Glance ■Contents at a Glance iii ■Contents v ■About the Author xvii ■About the Technical Reviewer xviii ■Acknowledgments xix ■Introduction to the Third Edition xx Part 1: Introduction 1 ■Chapter 1: PHP: Design and Management 3 Part 2: Objects 9 ■Chapter 2: PHP and Objects 11 ■Chapter 3: Object Basics 15 ■Chapter 4: Advanced Features 41 ■Chapter 5: Object Tools 71 ■Chapter 6: Objects and Design 99 Part 3: Patterns 121 ■Chapter 7: What Are Design Patterns? Why Use Them? 123 ■Chapter 8: Some Pattern Principles 131 ■Chapter 9: Generating Objects 145 ■Chapter 10: Patterns for Flexible Object Programming 169 ■Chapter 11: Performing and Representing Tasks 189 ■Chapter 12: Enterprise Patterns 221 ■Chapter 13: Database Patterns 275 Part 4: Practice 315 ■Chapter 14: Good (and Bad) Practice 317 ■Chapter 15: An Introduction to PEAR and Pyrus 323 ■Chapter 16: Generating Documentation with phpDocumentor 347 ■Chapter 17: Version Control with Subversion 361 ■Chapter 18: Testing with PHPUnit 379 ■Chapter 19: Automated Build with Phing 407 ■Chapter 20: Continuous Integration 427 Part 5: Conclusion 451 ■Chapter 21: Objects, Patterns, Practice 453 ■Appendix A: Bibliography 463 ■Appendix B: A Simple Parser 467 ■Index 219 iv v Contents ■Contents at a Glance iii ■Contents v ■About the Author xvii ■About the Technical Reviewer xviii ■Acknowledgments xix ■Introduction to the Third Edition xx Part 1: Introduction 1 ■Chapter 1: PHP: Design and Management 3 The Problem 3 PHP and Other Languages 4 About This Book 5 Objects 6 Patterns 6 Practice 6 What’s New in the Third Edition 7 Summary 7 Part 2: Objects 9 ■Chapter 2: PHP and Objects 11 The Accidental Success of PHP Objects 11 In the Beginning: PHP/FI 11 Syntactic Sugar: PHP 3 11 PHP 4 and the Quiet Revolution 12 ■ CONTENTS vi Change Embraced: PHP 5 13 Into the Future 14 Advocacy and Agnosticism: The Object Debate 14 Summary 14 ■Chapter 3: Object Basics 15 Classes and Objects 15 A First Class 15 A First Object (or Two) 16 Setting Properties in a Class 17 Working with Methods 19 Creating a Constructor Method 21 Arguments and Types 22 Primitive Types 22 Taking the Hint: Object Types 25 Inheritance 27 The Inheritance Problem 27 Working with Inheritance 31 Public, Private, and Protected: Managing Access to Your Classes 35 Summary 39 ■Chapter 4: Advanced Features 41 Static Methods and Properties 41 Constant Properties 44 Abstract Classes 45 Interfaces 47 Late Static Bindings: The static Keyword 48 Handling Errors 51 Exceptions 52 Final Classes and Methods 57 Working with Interceptors 58 Defining Destructor Methods 62 ■ CONTENTS vii Copying Objects with __clone() 63 Defining String Values for Your Objects 65 Callbacks, Anonymous Functions and Closures 66 Summary 70 ■Chapter 5: Object Tools 71 PHP and Packages 71 PHP Packages and Namespaces 71 Autoload 80 The Class and Object Functions 81 Looking for Classes 82 Learning About an Object or Class 83 Learning About Methods 84 Learning About Properties 85 Learning About Inheritance 85 Method Invocation 86 The Reflection API 87 Getting Started 87 Time to Roll Up Your Sleeves 88 Examining a Class 90 Examining Methods 91 Examining Method Arguments 93 Using the Reflection API 94 Summary 97 ■Chapter 6: Objects and Design 99 Defining Code Design 99 Object-Oriented and Procedural Programming 100 Responsibility 103 Cohesion 104 Coupling 104 Orthogonality 104 Choosing Your Classes 105 ■ CONTENTS viii Polymorphism 106 Encapsulation 107 Forget How to Do It 108 Four Signposts 109 Code Duplication 109 The Class Who Knew Too Much 109 The Jack of All Trades 109 Conditional Statements 110 The UML 110 Class Diagrams 110 Sequence Diagrams 117 Summary 119 Part 3: Patterns 121 ■Chapter 7: What Are Design Patterns? Why Use Them? 123 What Are Design Patterns? 123 A Design Pattern Overview 125 Name 125 The Problem 125 The Solution 126 Consequences 126 The Gang of Four Format 126 Why Use Design Patterns? 127 A Design Pattern Defines a Problem 127 A Design Pattern Defines a Solution 127 Design Patterns Are Language Independent 127 Patterns Define a Vocabulary 127 Patterns Are Tried and Tested 128 Patterns Are Designed for Collaboration 128 Design Patterns Promote Good Design 128 PHP and Design Patterns 129 Summary 129 [...]... 14 3 Patterns for Generating Objects .14 3 Patterns for Organizing Objects and Classes .14 3 Task-Oriented Patterns 14 3 Enterprise Patterns 14 4 Database Patterns 14 4 Summary 14 4 ■Chapter 9: Generating Objects 14 5 Problems and Solutions in Generating Objects 14 5 The Singleton Pattern 14 9 The... 13 1 The Pattern Revelation 13 1 Composition and Inheritance 13 2 The Problem .13 2 Using Composition .13 5 Decoupling 13 7 The Problem .13 7 Loosening Your Coupling 13 9 Code to an Interface, Not to an Implementation 14 1 The Concept That Varies 14 2 Patternitis 14 3 The Patterns. .. 17 9 The Problem .17 9 Implementation 18 1 Consequences 18 5 The Facade Pattern 18 5 The Problem .18 5 Implementation 18 6 Consequences 18 7 Summary 18 7 ■Chapter 11 : Performing and Representing Tasks .18 9 The Interpreter Pattern 18 9 The Problem .18 9... into three main parts: objects, patterns, and practice Objects I begin Part 2 with a quick look at the history of PHP and objects, charting their shift from afterthought in PHP 3 to core feature in PHP 5 You can still be an experienced and successful PHP programmer with little or no knowledge of objects For this reason, I start from first principles to explain objects, classes, and inheritance Even at... principal architects of PHP 3 were Zeev Suraski and Andi Gutmans PHP 3 was a complete rewrite of PHP/ FI 2.0, but objects were not deemed a necessary part of the new syntax 11 CHAPTER 2 ■ PHP AND OBJECTS According to Zeev Suraski, support for classes was added almost as an afterthought (on 27 August 19 97, to be precise) Classes and objects were actually just another way to define and access associative... .16 3 Implementation 16 3 But That’s Cheating! 16 6 Summary 16 7 ■Chapter 10 : Patterns for Flexible Object Programming 16 9 Structuring Classes to Allow Flexible Objects 16 9 The Composite Pattern 16 9 The Problem .17 0 Implementation 17 2 Consequences 17 5 Composite in Summary 17 8... clean and clever code, we want a codebase that is designed well for developers and users alike The mechanics of sharing, reading, and deploying the project should be as important as the code itself 8 PART 2 ■■■ Objects 9 CHAPTER 1 ■ PHP: DESIGN AND MANAGEMENT 10 CHAPTER 2 ■■■ PHP and Objects Objects were not always a key part of the PHP project In fact, they have been described as an afterthought by PHP s... coverage of objects by summarizing the development of PHP s object-oriented features We will look at • PHP/ FI 2.0: PHP, but not as we know it • PHP 3: Objects make their first appearance • PHP 4: Object-oriented programming grows up • PHP 5: Objects at the heart of the language • PHP 6: A glimpse of the future The Accidental Success of PHP Objects With so many object-oriented PHP libraries and applications... 3 01 The Problem .3 01 Implementation 302 Consequences 307 The Selection Factory and Update Factory Patterns 307 The Problem .307 Implementation 307 Consequences 311 What’s Left of Data Mapper Now? 311 Summary 313 Part 4: Practice 315 ■Chapter 14 : Good (and Bad) Practice. .. .14 9 Implementation 15 0 Consequences 15 2 Factory Method Pattern 15 2 The Problem .15 3 Implementation 15 5 Consequences 15 7 Abstract Factory Pattern 15 7 The Problem .15 8 Implementation 15 9 ix ■ CONTENTS Consequences 16 1 Prototype 16 2 . Part 2: Objects 9 ■Chapter 2: PHP and Objects 11 The Accidental Success of PHP Objects 11 In the Beginning: PHP/ FI 11 Syntactic Sugar: PHP 3 11 PHP 4 and the Quiet Revolution 12 ■ CONTENTS. Duplication 10 9 The Class Who Knew Too Much 10 9 The Jack of All Trades 10 9 Conditional Statements 11 0 The UML 11 0 Class Diagrams 11 0 Sequence Diagrams 11 7 Summary 11 9 Part 3: Patterns 12 1 ■Chapter. Practice i PHP Objects, Patterns, and Practice Third Edition ■ ■ ■ Matt Zandstra ii PHP Objects, Patterns, and Practice, Third Edition Copyright © 2 010 by Matt Zandstra