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Beginning

Drupal®

Jacob Redding

Redding

$39.99 USA $47.99 CAN

Drupal is an open source framework and content management system used to create web sites that is known for its steep learning curve. This introduction offers you a clear and solid understanding of Drupal so that you can get started programming a Drupal site immediately. Author Jacob Redding walks you through the installation and configuration of a Drupal web site and presents a clear understanding of Drupal’s hook system, theming layer, views, and API. Throughout the book, helpful examples and step-by-step instructions provide you with a strong proficiency in the power and capabilities of Drupal.

Beginning Drupal:

• Addresses ways to manage and moderate comments on your site

• Looks at why Drupal’s node system is the pivotal structure of Drupal

• Explains the basics of the views modules and shows you how to control the output of your content

• Guides you through Drupal’s built-in themes and modifying them to suit your needs

• Examines the power of Drupal’s community and demonstrates how to become engaged with it

• Covers the entire module-development process, including creating custom configuration settings, blocks, and database tables

Jacob Redding is an open source evangelist and technologist, and an active member in the Drupal community. In addition to managing several modules on drupal.org and providing Drupal-related training and consulting, he is also a board member on the Drupal Association.

Wrox Beginning guides are crafted to make learning programming languages and technologies easier than you think, providing a structured, tutorial format that will guide you through all the techniques involved.

Web Page Design

Shorten the learning curve and quickly leverage the power of Drupal

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Beginning

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BEGINNING DRUPAL®

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxi

CHAPTER 1 Introducing Drupal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

CHAPTER 2 Installing Drupal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

CHAPTER 3 Your First Drupal Website . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

CHAPTER 4 Administration — Confi guration, Modules, and Reporting . . . . . . . . . . . 49

CHAPTER 5 Administration — Blocks, Menus, and Themes . . . . . . . . . . . . . . . . . . . . 69

CHAPTER 6 Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

CHAPTER 7 User Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

CHAPTER 8 Taxonomy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157

CHAPTER 9 Search, Performance, Statistics, and Reporting . . . . . . . . . . . . . . . . . . . 173

CHAPTER 10 Triggers, Actions, Workfl ow, and Rules . . . . . . . . . . . . . . . . . . . . . . . . . . 189

CHAPTER 11 Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

CHAPTER 12 Internationalization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241

CHAPTER 13 Theming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263

CHAPTER 14 Contributed Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299

CHAPTER 15 Custom Modules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315

CHAPTER 16 Development Hooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331

CHAPTER 17 Module Development Start to Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347

CHAPTER 18 Advanced Drupal Installations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379

CHAPTER 19 Prefl ight Checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401

APPENDIX Exercises and Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .417

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433

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BEGINNING

Drupal®

Jacob Redding

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Beginning Drupal®

Published byWiley Publishing, Inc.10475 Crosspoint BoulevardIndianapolis, IN 46256www.wiley.com

Copyright © 2010 by Wiley Publishing, Inc., Indianapolis, Indiana

Published by Wiley Publishing, Inc., Indianapolis, Indiana

Published simultaneously in Canada

ISBN: 978-0-470-43852-7

Manufactured in the United States of America

10 9 8 7 6 5 4 3 2 1

No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions.

Limit of Liability/Disclaimer of Warranty: The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifi cally disclaim all warranties, including without limitation warranties of fi tness for a particular purpose. No warranty may be created or extended by sales or pro-motional materials. The advice and strategies contained herein may not be suitable for every situation. This work is sold with the understanding that the publisher is not engaged in rendering legal, accounting, or other professional services. If professional assistance is required, the services of a competent professional person should be sought. Neither the pub-lisher nor the author shall be liable for damages arising herefrom. The fact that an organization or Web site is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Web site may provide or recommendations it may make. Further, readers should be aware that Internet Web sites listed in this work may have changed or disappeared between when this work was written and when it is read.

For general information on our other products and services please contact our Customer Care Department within the United States at (877) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002.

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books.

Library of Congress Control Number: 2009930281

Trademarks: Wiley, the Wiley logo, Wrox, the Wrox logo, Wrox Programmer to Programmer, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affi liates, in the United States and other countries, and may not be used without written permission. Drupal is a registered trademark of Dries Buytaert. All other trademarks are the property of their respective owners. Wiley Publishing, Inc. is not associated with any product or ven-dor mentioned in this book.

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This book is fi rst and foremost dedicated to the

Drupal community, a melting pot of some of the

most talented and intelligent people I have had the

pleasure of working with. Equally important is Diana

Kuan. She stuck by me while I wrote this book, pulled

incredible hours with the Drupal Association, traveled

to countless Drupal events and went crazy trying to

keep up with the intense development of Drupal 7.

Thank you Diana.

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CREDITS

EXECUTIVE EDITOR

Carol Long

PROJECT EDITOR

Ed Connor

TECHNICAL EDITOR

Joshua Brauer

PRODUCTION EDITOR

Kathleen Wisor

COPY EDITOR

Kathi Duggan

EDITORIAL DIRECTOR

Robyn B. Siesky

EDITORIAL MANAGER

Mary Beth Wakefi eld

MARKETING MANAGER

Ashley Zurcher

PRODUCTION MANAGER

Tim Tate

VICE PRESIDENT AND EXECUTIVE GROUP

PUBLISHER

Richard Swadley

VICE PRESIDENT AND EXECUTIVE PUBLISHER

Barry Pruett

ASSOCIATE PUBLISHER

Jim Minatel

PROJECT COORDINATOR, COVER

Lynsey Stanford

COMPOSITOR

Jeff Lytle, Happenstance Type-O-Rama

PROOFREADER

Carrie Hunter, Word One, New York

INDEXER

Robert Swanson

COVER DESIGNER

Michael E. Trent

COVER IMAGE

© Jim Jurica/istockphoto

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ABOUT THE AUTHOR

JACOB REDDING got his start in Drupal in 2005 after 10 years in the IT industry building custom software with everything from Microsoft to Linux and UNIX technologies. He has since become heavily involved in the Drupal association and Drupal communities around the world, speaking and leading classes in not only New York, San Francisco, Boston, and Washington DC, but also far-fl ung locales such as China and Jordan. An enthusiastic advocate of open-source, he currently spends most of his time providing project man-agement and training on Drupal-based websites.

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ACKNOWLEDGMENTS

DIANA KUAN DESERVES the top spot here. Serving as a part-time editor, proofreader, supporter, and impromptu student she helped set the fl ow of the book, proofread nearly every page, and tested many of the exercises. Without her assistance and support this book would have taken yet another year, an outcome that would have surely sent the publisher’s henchmen out to get me.

Jason Chinn, Mr. Magicspark, helped me through the rough spots of theming including building the nice Drupal chocolate theme used in Chapter 13. Without him the theming chapter would have been a rambling mess.

My students: To those in China: My students in Jordan caught me during a critical time of this book and unknowingly tested several of the exercises in the book, thank you for secretly helping to create this book. I can’t leave out those in my home country of the United States, thank you for listening to me ramble about in class. I hope that I have been a useful part of your Drupal journeys.

Joshua Brauer: My technical editor. Although we have never met and I’m not entirely sure how we were paired together, the odd in-book synergy somehow worked. I was able to see through his trying-to-be-nice commentary that brow beat me into thoroughly revising the chapters into something useable.

Carol Long and Ed Connor at Wiley/Wrox: Oh boy. These two had no idea what they signed up for. The book started on very early versions of Drupal 7 and was revised too many times for them to count. Their patience and tolerance of my “I’ll get it to you soon-ish” (heavy emphasis on –ish) and “by the way Drupal 7 changed so I have to rewrite the entire chapter” is much appreciated.

The entire Drupal community: You gals and guys are amazing. From small meetups in Beijing, large DrupalCamps in Los Angeles, collaborative working sessions in New York and the awesome DrupalChix group, you (the Drupal community) are amazing individuals to know and to collaborate with. With the book fi nally complete I hope to see you all in IRC more often.

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CONTENTS

INTRODUCTION xxi

INTRODUCING DRUPAL CHAPTER 1: 1

History of Drupal 2

Why is the Name Drupal? 2

Who is Drupal? 2

The Drupal Community 2

Where Is the Community? 3

Professional Support 4

The Drupal Association 5

Summary 6

INSTALLING DRUPAL CHAPTER 2: 9

Getting Started with Drupal 10

Installing a Single Drupal Website 10

Installing Drupal 13

Installation Profi les 16

Installing Drupal in Diff erent Languages 16

Acquia’s Stack Installer 16

Breaking It Down 19

Don’t Hack Core 19

Core Files 20

Sites Folder 21

What’s in a Site’s Folder? 21

Inheritance and Overrides 22

Summary 24

YOUR FIRST DRUPAL WEBSITE 2CHAPTER 3: 7

Adding Content 27

Diff erences between Articles and Pages 29

Content Summaries 30

Modifying the Defaults 30

Modifying Your Menus 31

Adding Blocks to Your Website 33

Getting in Contact 34

Adding the Contact Form to Your Main Menu 36

Summing Up the Contact Form 37

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x

CONTENTS

Exploring Your Site’s Permissions 38

Creating a Members-Only Site 39

Exploring Roles 39

Wrapping up Users and Permissions 43

Time for a New Look 43

Time for Something Diff erent 44

Cron 45

Manually? No Way! Let the Computer Do It 46

A Need for Speed 46

Summary 47

ADMINISTRATION — CONFIGURATION, MODULES, AND CHAPTER 4: REPORTING 49

Confi guration 50

System — Site Information 51

System — Actions 53

Regional and Language — Settings 53

Regional and Language — Translate 54

Media 54

Media — File System 55

Temporary Directory 56

PHP File Size Limitations 56

Media — Image Toolkit 57

People and Permissions 57

Web Services 57

Web Services — RSS Publishing 58

Web Services — Feed Aggregator 58

Content Authoring — Text Formats 58

Explore the Filtered HTML Text Format 59

Modify Text 59

Add Text 59

Remove Text 59

Interpreting Text 60

Choosing Roles and the Importance of the Order 60

Confi guring the Filters 61

The Order Matters 61

Additional Filters 61

Writing Your Own Filter 62

Search and Metadata - Clean URLs 62

Apache 63

A Need for Speed 63

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CONTENTS

IIS 64

Search and Metadata — URL Aliases 64

Alias Your Way to a Better Search Ranking 65

Maintenance Mode 65

IP Address Blocking 66

Summary 67

ADMINISTRATION — BLOCKS, MENUS, AND THEMES 6CHAPTER 5: 9

Blocks 70

Block Visibility 73

Block Visibility Using PHP 75

Menus 77

Adding a Menu Link Directly on Content 80

A Word On Permissions 80

Menu Settings 80

Related Modules 81

URL Aliases AKA Custom Paths 81

A Word on Permissions 83

Themes 83

Theme Administration 83

Theme Global Settings 84

Theme Settings Summary 85

Installing New Themes 85

Administrative Theme 86

Post Information 87

Summary 87

CONTENT 9CHAPTER 6: 1

Nodes 92

What is a Node? 92

Creating Custom Content Types 93

Submission Form Settings 95

Publishing Options 96

Display Settings 97

Comment Settings 97

Menu Settings 97

Adding an Image Upload Field 98

Multiple Fields for Multiple Images? 99

The Power of Image Field 99

Permissions 104

Revisions 105

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xii

CONTENTS

Digging Deeper Into Fields 106

Fields 106

Field Types (Type of Data to Store) 107

Widgets (Form Element) 107

Allowed Values List 109

Content Construction Kit (CCK) 109

Views 110

Administering Nodes 110

Content Moderation 111

Quick and Easy Moderation 111

Nodes in a Nutshell 111

Comments 112

Permissions 113

Comment Administration 113

Comment Administration Page 114

Comment Approval Queue (A.K.A Comment Moderation) 114

Comment Form 116

Allowing Rich Text Comments 116

WYSIWYG 117

Spam 117

RSS Aggregation 118

Displaying the Feed 120

Confi guring the Aggregation Settings 121

Summary 122

USER MANAGEMENT 12CHAPTER 7: 5

Creating User Accounts 126

People 126

Anonymous Users 126

Creating Accounts 126

Approving Accounts in Moderation 128

Setting a Password During Registration 129

Canceling Accounts 129

Setting Up Account E-mails 129

Using OpenID 130

Creating Roles and Permissions 132

Administrator Role 135

Creating Custom User Profi les 135

Profi les in Drupal 7 135

User Profi les vs. User Fields 136

Using Fields for Profi les 136

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CONTENTS

Using the Core Profi le Module 137

Controlling Access to User Profi les 140

Hidden Fields 142

Visibility Options Summarized 143

Tracking User Activity 143

Using Views to Create Custom Tracking Pages and Blocks 144

Custom Administration Pages with Views 150

User Sessions 153

Forcing Sessions to Expire 154

Summary 155

TAXONOMY 15CHAPTER 8: 7

In Simple Terms 157

Terminology 158

Vocabularies 158

Terms 159

Advanced Options 159

Using Terms on Your Content 160

Taxonomy Term Field Settings 162

A Term’s Parent/Child Relationship 164

Using Views to Display Term Pages 165

Display Multiple Terms on a Single Page 167

API 168

Theming Considerations 168

Customizing Each Section 168

Useful Contributed Modules 169

Summary 170

SEARCH, PERFORMANCE, STATISTICS, AND REPORTING 17CHAPTER 9: 3

Search 174

Indexing Your Content 175

Advanced Search Settings 176

Indexing Settings 176

CJK Handling 177

Content Ranking 177

Faceted Search 177

Outsourcing Search 178

If You Don’t Want to Outsource 178

Performance 178

Caching 178

Cache Blocks 179

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CONTENTS

Page Cache for Anonymous Users 179

Minimum Cache Lifetime 179

Bandwidth Optimization 180

Clearing Cached Data 180

The Need for Speed 181

Reporting 182

Status Report 183

Recent Log Entries 183

Statistics 184

Access Log 185

Content Views 185

Performance Considerations 185

Summary 186

TRIGGERS, ACTIONS, WORKFLOW, AND RULES 18CHAPTER 10: 9

Triggers and Actions 190

Working with Actions 190

Working with Triggers 191

Next Steps 193

Workfl ow 193

Rules 200

Features of the Rules Module 201

Conditions 203

Scheduler and Rule Sets 206

Input Evaluators 209

Summary 210

VIEWS 21CHAPTER 11: 3

Advanced Help 214

Overview of Views 214

The Frontpage View 215

Explore the Frontpage View 215

Displays 218

Style Settings 220

Creating a Photo Gallery 222

Arguments 225

Exposed Filters 229

Exposed Items in a Block 231

Making Your View Accessible via a Tab 232

Relationships 234

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CONTENTS

Permissions 235

All-Views Permissions 236

Per-View Permissions 236

Caching (AKA Performance) 236

Caching 236

Block Caching 237

Best Practices 237

Advanced Views 238

Summary 238

INTERNATIONALIZATION 24CHAPTER 12: 1

A Bit of Terminology 241

Localizing 242

Regional Settings 242

Date and Time 243

Localizing Your Site’s Interface 243

Your Site’s Primary Language 249

Language Negotiation 249

Completing Your Site’s Localization 252

Making Translation Easy with the L10N Client 253

Translating Your Content 258

Beyond the Basics 260

Summary 261

THEMING 26CHAPTER 13: 3

Administering Themes 264

Installing New Themes 264

Confi guring Your Themes 265

Custom Theming 266

Template Files 270

Theme Functions 274

Reviewing the Last Five Exercises 279

Sub-Themes 280

Zen Base Theme 282

.info File 282

Removing Theme Settings 282

Style Sheets 283

JavaScript 284

Regions 285

Template Files (.tpl.php) 286

page.tpl.php 286

node.tpl.php 287

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CONTENTS

comment.tpl.php 287

block.tpl.php 287

Template Suggestions 288

Preprocess Functions 288

Adding New Variables 289

Template Suggestions 289

Swapping Theme Functions and Template Files 290

Moving a Theme Function to a Template File 290

Moving a Template File to a Theme Function 290

Theme Registry 291

Theme Engines 294

Summary 296

CONTRIBUTED MODULES 29CHAPTER 14: 9

Contributed and Custom Modules 299

Determining Your Needs 300

Fulfi lling Your Needs 301

Lullabot Podcast 301

Top Drupal Modules 302

Showcases 302

Planet Drupal 303

Finding Modules 303

Search Drupal.org 303

Google 304

Drupalmodules.com 304

IRC and the Drupal Community 305

RSS Feeds 305

Twitter 305

Is It the Right Module? 306

Project Page 306

Google 309

Coder Module 309

Tests 309

Be a Follower 309

Take It Slow 310

Set Up a Development Environment 311

Avoid the Buff et 311

Summary 312

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CONTENTS

CUSTOM MODULES 31CHAPTER 15: 5

What Is a Module? 315

Hooks 317

More Information 319

Modules Step by Step 319

Step 1: Choose a Name 319

Step 2: Create the .info File 320

Step 3: Create the .module File 321

Creating a Page 321

Capturing Custom URLs with hook_menu 322

Modifying Existing Modules 324

Patching 325

Creating a Patch 325

The Value of the Patch 327

When to Modify 327

Summary 327

DEVELOPMENT HOOKS 33CHAPTER 16: 1

Hooks: A Module’s Starting Point 332

Community Documentation 332

The Hooks 333

hook_menu 333

Making Your Modules Themeable 339

The t() Function 340

Theme Functions and Template Files 341

Summary 344

MODULE DEVELOPMENT START TO FINISH 34CHAPTER 17: 7

The Module 348

Beginning Your Module 349

Implementing a hook 350

Adding Custom Confi guration Settings 351

Custom Module Settings 352

How Did it Become an Option at Confi guration? 353

How Did the Settings Form Appear? 354

Where Are the Settings Saved? 354

Filtering on Multiple Words 355

A Quick Review of the New PHP Code 356

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CONTENTS

Helping Your Users 356

Permission Handling 358

Storing Data in a Custom Table 359

Database Abstraction Layer 360

Drupal Query Functions 361

Displaying the Results on the User’s Profi le 365

Database Summary 367

Creating a Bulletproof Site with SimpleTest 367

Test Driven Development 367

How SimpleTest Performs Its Testing 369

Writing Your Own SimpleTest 369

SimpleTest Assertions 371

Adding the Tests to Your Module 373

Summing Up SimpleTest 375

Summary 375

ADVANCED DRUPAL INSTALLATIONS 37CHAPTER 18: 9

Drush 380

But Wait There’s More! 381

Using CVS to Manage Drupal 382

What is CVS? 382

What is SVN? 382

Installing CVS 383

Installing and Upgrading Drupal using CVS 383

Understanding CVS Tags 385

How Does This Relate to CVS? 385

Branches and Tags 386

Installing Modules from the CVS Repository 386

One Drupal, Many Websites 387

Example 1: Multiple Independent Websites 388

Example 2: Multiple Related Websites 389

Sites.php 392

Settings.php 392

$databases 393

Scalability 394

$db_prefi x 394

$baseurl 395

$ini_set 395

$reverse_proxy 396

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CONTENTS

Variable Overrides 396

String Overrides 396

IP Blocking 397

Summary 397

PREFLIGHT CHECKLIST 40CHAPTER 19: 1

Prefl ight Checklist 402

Site Information 402

User Settings 402

Site Maintenance 402

SPAM 403

SEO 403

Search 403

Performance 404

Disaster Recovery 404

SEO 404

SEO Best Practices 405

The Importance of URLs 405

XML Sitemap 405

Submitting Your Sitemap to Search Engines 408

Analyzing Your Site with Google 411

Dashboard 413

Summary 415

APPENDIX: EXERCISES AND ANSWERS 417

INDEX 433

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INTRODUCTION

OVER THE PAST FEW YEARS, the Web has undergone dramatic changes. What originally started as a handful of static web pages with a few e-commerce sites in the mix has now turned into a frenzy of collaboration and information sharing. New websites are expected to meet a certain level of inter-activity and information-sharing. RSS feeds, blogs, and podcasts are just a few of the current stan-dards. Photo uploads with auto-resizing and cropping, video and audio embedding, and even web APIs are quickly becoming the new standard-website functions.

Years ago, when I started creating dynamic websites, I began as most developers did, by writing my own custom content management system (CMS). My experience was not unlike that of others who followed the same path. The system was light and fast, and did everything that I, and my clients, asked — until a new feature emerged on the Web, and my software had to play catch-up. Soon I was buried under a pile of feature requests and bug fi xes, which left me with no time to innovate. My quest for a better solution led me through a maze of software packages, until a friend told me about Drupal.

According to him Drupal has two really great things going for it. The fi rst is that it’s built on a mod-ular structure, so it can quickly adapt to custom and unique scenarios. The second is that it is built around a community that is growing every day. When a new feature emerges on the Web, chances are someone has already gotten it to work within Drupal. The community factor is what sold me.

Now that I have been working with Drupal for a few years, I am in awe at how well the community has organized itself and, as a result, kept itself and the Drupal project on the cutting edge of web technology. Drupal has moved from being a piece of software that modularized the latest Internet technologies, to a platform that creates the latest technologies. The community made this happen.

You are now a part of this awesome community. Welcome.

Who This Book Is For

This book was written for people who want a robust website and aren’t afraid to get their hands dirty.

Maybe you’re the leader of a nonprofi t who wants to organize your constituency through a community-driven website. You have a bit of prior experience in creating HTML pages by hand or with another CMS. You’re now ready to dig in and create your community’s website, and Drupal is your tool of choice, but you want to be on the fast track.

Perhaps you’re an established developer and possess the skills to create your own custom CMS or have experience with other software packages. You’re looking for defi nitions and examples on Drupal’s terminology and structure so that you can take advantage of Drupal’s fast development cycle that you hear so much about.

To get the most out of this book, you should already possess or have a strong desire to obtain expe-rience in web development with HTML, JavaScript, or PHP. I did not set out to write a book that guides you step-by-step through building a specifi c website such as one for a restaurant or bakery. Instead, I set out to write a book that will help you understand how you can use Drupal to take the

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INTRODUCTION

vision in your head and apply it to the Web. For example, when you understand that you need a new form of content, fl ip to Chapter 6, "Content," which discusses all aspects of content in depth, including creating, administering, moderating, and controlling that content.

Experienced developers who are looking to propel themselves on the fast track to custom mod-ule development might fi nd it useful to skim Chapters 2 through 4, and then skip forward to the later chapters on module development. I would suggest that you spend a bit of time on Chapter 6, "Content," and Chapter 10, "Workfl ow and Actions," and Chapter 11, "Views." A good under-standing of these chapters may save you countless development hours.

What This Book Covers

This book focuses on Drupal 7, but the changes since Drupal 6 are highlighted where appropri-ate. This book walks you through the entire process of creating a Drupal website. It starts with the installation, moves to administration and confi guration, and then covers users and permissions. The book also discusses content (including nodes, users, and blocks), Drupal’s infamous taxonomy sys-tem, tips on how to make your site not look like a Drupal site, and instructions on expanding your site with contributed and/or custom modules.

How This Book Is Structured

I often train others on how to use Drupal, so this book is structured similar to a training manual. The chapters are ordered in a manner that builds upon the topics of the previous chapter. For example, the chapter on Views is after the chapters on users, content, and taxonomy, because a view works with all of these items. I believe this order will help you understand the overall fl ow and structure of Drupal. Each chapter, however, is a thorough examination of its topic.

I don’t expect you to read the book cover to cover before building your website. You should read this book alongside your development and use it as an aid or reference.

If you are new to Drupal, I recommend that you read at least the fi rst parts of each chapter, but you can move to the next chapter if the topic becomes too complex or just plain boring. You can then revisit each chapter when you need clarifi cation or more information.

Experienced developers or those with previous Drupal experience may fi nd it benefi cial to skip to the chapters that matter most to them. Each chapter is designed to be independent, although the examples in one chapter may build upon the examples in the previous chapter. If you fi nd this to be the case, simply fl ip back one chapter and follow the last example to catch up.

What You Need to Use This Book

The book covers Drupal version 7, which has the following requirements:

Webserver: Apache 1.3 or 2.x or IIS 6+ ➤

Database server: MySQL 5+ or Postgres 8.3+ ➤

PHP 5.2 or higher ➤

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INTRODUCTION

The XAMPP project for Microsoft Windows, Linux, and Mac OS X as well as the MAMP project for Mac OS X contain all of these requirements in a single downloadable package.

Please visit http://drupal.org/requirements for up-to-date system requirements.

CONVENTIONS

To help you get the most from the text and keep track of what’s happening, I’ve used a number of conventions throughout the book.

Exercises that you can try out for yourself generally appear in a box like this:

What You Will Be Doing in this ExerciseTRY IT OUT

Each Try It Out consists of an exercise you should work through, following the text in the book.

1. They usually consist of a set of steps.

2. Each step has a number.

3. Follow the steps using your copy of the database.

How It Works

After each Try It Out, the code you’ve typed will be explained in detail.

WARNING Boxes like this one hold important, not-to-be forgotten information that is directly relevant to the surrounding text.

NOTE Notes, tips, hints, tricks, and asides to the current discussion are off set and placed in italics like this.

This book also uses the following styles to set apart non-standard text:

New and important terms are ➤ italicized.

A combination of two or more keyboard strokes is presented like this: Ctrl+A. ➤

File names, URLs, and code within the text are shown in a monofont, like so: ➤ persistence.

properties.

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INTRODUCTION

Separate lines of code are formatted in the following ways: ➤

Monofont type with no highlighting is used for most code examples.Bold is used to emphasize code that’s particularly important in the present context.

SOURCE CODE

As you work through the examples in this book, you may choose either to type in all the code man-ually, or to use the source code fi les that accompany the book. All the source code used in this book is available for download at http://www.wrox.com. When at the site, simply locate the book’s title (use the Search box or one of the title lists) and click the Download Code link on the book’s detail page to obtain all the source code for the book. Code that is included on the Web site is highlighted by the following icon:

Listings include the fi lename in the title. If it is just a code snippet, you’ll fi nd the fi lename in a code note such as this:

code snippet fi lename

NOTE Because many books have similar titles, you may fi nd it easiest to search by ISBN. This book’s ISBN is 978-0-470-43852-7.

Once you download the code, just decompress it with your favorite compression tool. Alternately, you can go to the main Wrox code download page at http://www.wrox.com/dynamic/books/download.aspx to see the code available for this book and all other Wrox books.

ERRATA

We make every effort to ensure that there are no errors in the text or in the code. However, no one is perfect, and mistakes do occur. If you fi nd an error in one of our books, like a spelling mistake or faulty piece of code, we would be very grateful for your feedback. By sending in errata you may save another reader hours of frustration and at the same time you will be helping us provide even higher quality information.

To fi nd the errata page for this book, go to http://www.wrox.com and locate the title using the Search box or one of the title lists. Then, on the book details page, click the Book Errata link. On

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INTRODUCTION

this page you can view all errata that has been submitted for this book and posted by Wrox edi-tors. A complete book list including links to each book’s errata is also available at www.wrox.com/misc-pages/booklist.shtml.

If you don’t spot “your” error on the Book Errata page, go to www.wrox.com/contact/techsup-port.shtml and complete the form there to send us the error you have found. We’ll check the information and, if appropriate, post a message to the book’s errata page and fi x the problem in sub-sequent editions of the book.

P2P.WROX.COM

For author and peer discussion, join the P2P forums at p2p.wrox.com. The forums are a Web-based system for you to post messages relating to Wrox books and related technologies and interact with other readers and technology users. The forums offer a subscription feature to e-mail you topics of interest of your choosing when new posts are made to the forums. Wrox authors, editors, other industry experts, and your fellow readers are present on these forums.

At http://p2p.wrox.com you will fi nd a number of different forums that will help you not only as you read this book, but also as you develop your own applications. To join the forums, just follow these steps:

1. Go to p2p.wrox.com and click the Register link.

2. Read the terms of use and click Agree.

3. Complete the required information to join as well as any optional information you wish to provide and click Submit.

4. You will receive an e-mail with information describing how to verify your account and com-plete the joining process.

NOTE You can read messages in the forums without joining P2P but in order to post your own messages, you must join.

When you join, you can post new messages and respond to messages other users post. You can read messages at any time on the Web. If you would like to have new messages from a particular forum e-mailed to you, click the Subscribe to this Forum icon by the forum name in the forum listing.

For more information about how to use the Wrox P2P, be sure to read the P2P FAQs for answers to questions about how the forum software works as well as many common questions specifi c to P2P and Wrox books. To read the FAQs, click the FAQ link on any P2P page.

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Introducing Drupal

WHAT YOU WILL LEARN IN THIS CHAPTER:

History of Drupal ➤

Drupal’s community ➤

How to fi nd and participate in the community, including: IRC, ➤

Meetups, Camps, and Drupal conferences

Professional Drupal support ➤

The Drupal Association ➤

What is Drupal? If this is your fi rst time using Drupal, you’re probably trying to answer this yourself, and you may have heard confl icting answers. Often Drupal is described as a content management system, whereas other times, it’s called a content management framework. So is it a system or a framework? Here’s a simple defi nition:

Drupal is an open source software application that manages the content of and builds websites and web applications. It can be used to create a web blog, e-commerce store, photo gallery, or social networking website.

That seems straightforward, right? In fact, it sounds a lot like Joomla!, Wordpress, Zope, and many other content management systems (CMSs). So why do people use the term content management platform or content management framework?

The use of the terms platform and framework is an attempt to describe Drupal as a base or a foundation onto which you build your desired websites or web applications. Out of the box, Drupal can be used to instantly create a website with users, articles, blogs, comments, and a forum. With a few modules from http://drupal.org it can be transformed into an e-commerce site, a group photo gallery, and more. Drupal is also built around a modular core and a strong

1

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2 ❘ CHAPTER 1 INTRODUCING DRUPAL

application programming interface (API) so you can quickly and easily extend Drupal to build the site of your dreams. This leads to the following, more technical defi nition:

Drupal is a modular framework written in the PHP scripting language that contains a CMS, a module system, and an API for rapid development of websites and web applications.

An example I’ve used often is Lego systems. You can purchase the race car Lego set and build the provided example race car. You could also build a luxury car with the same Lego set. If you purchase the rocket ship Lego set, you could combine the two and build a luxury rocket race car. After all, it’s only a set of blocks that you put together using your imagination. Drupal is built on the same idea — it’s a set of modules that you mix and match to build your perfect website or web application.

HISTORY OF DRUPAL

In 2000, Dries Buytaert, a student at the University of Antwerp, needed a method to communicate with his classmates and friends. He built a small web application so that he and his friends could leave notes for each other. After Dries graduated he moved the software over to drop.org and used it to experiment with new web technologies such as syndication, rating, and distributed authentica-tion. Dries also made the software freely available and licensed it under the GPL. It didn’t take long before the software’s unique modular structure gained notice and attracted a community of develop-ers and users.

Why is the Name Drupal?

When searching for domain names Dries accidentally misspelled the Dutch word dorp (meaning vil-lage) as drop. Accepting his mistake he registered and started to use the drop.org domain. In 2001 the project offi cially adopted the name Drupal. The Dutch word for drop is druppel, which changed to Drupal (pronounced “droo-puhl”) for easier pronunciation.

Who is Drupal?

As of this book’s writing, thousands of developers have contributed to the Drupal project. Many have contributed by adding modules and themes, providing support on drupal.org and the Internet Relay Chat (IRC) channels, and participating at meetups, DrupalCamps, and conferences around the world. Drupal has been recorded as having a developer base in almost every country in the world. It truly is an international open source project.

THE DRUPAL COMMUNITY

Drupal is not just software — it’s a community! The Drupal community is one of the largest and most supportive communities in the open source world. In fact, the community is so strong that it should be a major deciding factor when you’re choosing whether or not to use Drupal. Imagine building a site that requires a certain piece of functionality. You found a module that does 90

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