Phát triển web với PHP và MySQL - p 3 pdf

CONTENTS Previewing the Newsletter 703 Sending the Message 704 Extending the Project 709 Next 709 29 Building Web Forums 711 The Problem 712 Solution Components 712 Solution Overview 714 Designing the Database 716 Viewing the Tree of Articles 718 Expanding and Collapsing 721 Displaying the Articles 724 Using the treenode Class 725 Viewing Individual Articles 731 Adding New Articles 734 Extensions 741 Using an Existing System 741 Next 742 30 Generating Personalized Documents in Portable Format (PDF) 743 The Problem 744 Evaluating Document Formats 745 Paper 745 ASCII 745 HTML 745 Word Processor Formats 746 Rich Text Format 746 PostScript 747 Portable Document Format 748 Solution Components 749 Question and Answer System 749 Document Generation Software 749 Solution Overview 752 Asking the Questions 753 Grading the Answers 755 Generating an RTF Certificate 758 Generating a PDF Certificate from a Template 762 Generating a PDF Document Using PDFlib 765 A Hello World Script for PDFlib 766 Generating Our Certificate with PDFlib 770 xxi 00 7842 FM 3/6/01 3:38 PM Page xxi PHP AND MYSQL WEB DEVELOPMENT Problems with Headers 777 Extending the Project 778 Further Reading 778 PART VI Appendixes 779 A Installing PHP 4 and MySQL 781 Running PHP as a CGI Interpreter or Module 782 Installing Apache, PHP, and MySQL Under UNIX 783 Apache and mod_SSL 787 httpd.conf File—Snippets 790 Is SSL Working? 792 Installing Apache, PHP, and MySQL Under Windows 793 Installing MySQL Under Windows 793 Installing Apache Under Windows 795 Differences Between Apache for Windows and UNIX 798 Installing PHP for Windows 799 Installation Notes for Microsoft IIS 800 Installation Notes for Microsoft PWS 802 Other Configurations 802 B Web Resources 803 PHP Resources 804 MySQL and SQL Specific Resources 806 Apache Resources 806 Web Development 806 Index 807 xxii 00 7842 FM 3/6/01 3:38 PM Page xxii About the Authors Laura Thomson is a lecturer in Web programming in the Department of Computer Science at RMIT University in Melbourne, Australia. She is also a partner in the award-winning Web development firm Tangled Web Design. Laura has previously worked for Telstra and the Boston Consulting Group. She holds a Bachelor of Applied Science (Computer Science) degree and a Bachelor of Engineering (Computer Systems Engineering) degree with honors, and is currently completing her Ph.D. in adaptive Web sites. In her spare time, she enjoys sleeping. Laura can be contacted at laura@tangledweb.com.au. Luke Welling is a lecturer in software engineering and e-commerce in the School of Electrical and Computer Systems Engineering at RMIT University in Melbourne, Australia. He is also a partner in Tangled Web Design. He holds a Bachelor of Applied Science (Computer Science) degree and is currently completing a master’s degree in Genetic Algorithms for Communication Network Design. In his spare time, he attempts to perfect his insomnia. Luke can be contacted at luke@tangledweb.com.au. About the Contributors Israel Denis Jr. is a freelance consultant working on e-commerce projects throughout the world. He specializes in integrating ERP packages such as SAP and Lawson with custom Web solutions. He obtained a master’s degree in Electrical Engineering from Georgia Tech in Atlanta, Georgia in 1998. He is the author of numerous articles about Linux, Apache, PHP, and MySQL and can be reached via email at idenis@ureach.com. Chris Newman is a consultant programmer specializing in the development of dynamic Internet applications. He has extensive commercial experience in using PHP and MySQL to produce a wide range of applications for an international client base. A graduate of Keele University, he lives in Stoke-on-Trent, England, where he runs Lightwood Consultancy Ltd. More information on Lightwood Consultancy Ltd can be found at http://www.lightwood.net, and Newman can be contacted at chris@lightwood.net. 00 7842 FM 3/6/01 3:38 PM Page xxiii Dedication To our Mums and Dads. Acknowledgments We would like to thank the team at Sams for all their hard work. In particular, we would like to thank Shelley Johnston Markanday without whose dedication and patience this book would not have been possible. We would also like to thank Israel Denis Jr. and Chris Newman for their valuable contributions. We appreciate immensely the work done by the PHP and MySQL development teams. Their work has made our lives easier for a number of years now, and continues to do so on a daily basis. We thank Adrian Close at eSec for saying “You can build that in PHP” back in 1998. We also thank James Woods and all the staff at Law Partners for giving us such interesting work to test the boundaries of PHP with. Finally, we would like to thank our family and friends for putting up with us while we have been antisocial for the better part of a year. Specifically, thank you for your support to our family members: Julie, Robert, Martin, Lesley, Adam, Paul, Sandi, James, and Archer. 00 7842 FM 3/6/01 3:38 PM Page xxiv Tell Us What You Think! As the reader of this book, you are our most important critic and commentator. We value your opinion and want to know what we’re doing right, what we could do better, what areas you’d like to see us publish in, and any other words of wisdom you’re willing to pass our way. You can email or write me directly to let me know what you did or didn’t like about this book—as well as what we can do to make our books stronger. Please note that I cannot help you with technical problems related to the topic of this book, and that due to the high volume of mail I receive, I might not be able to reply to every message. When you write, please be sure to include this book’s title and author as well as your name and phone or email address. I will carefully review your comments and share them with the author and editors who worked on the book. E-mail: webdev@samspublishing.com Mail: Mark Taber Associate Publisher Sams Publishing 201 West 103rd Street Indianapolis, IN 46290 USA 00 7842 FM 3/6/01 3:38 PM Page xxv 00 7842 FM 3/6/01 3:38 PM Page xxvi Introduction Welcome to PHP and MySQL Web Development. Within its pages, you will find distilled knowledge from our experiences using PHP and MySQL, two of the hottest Web development tools around. In this introduction, we’ll cover • Why you should read this book • What you will be able to achieve using this book • What PHP and MySQL are and why they’re great • An overview of the new features of PHP 4 • How this book is organized Let’s get started. Why You Should Read This Book This book will teach you how to create interactive Web sites from the simplest order form through to complex secure e-commerce sites. What’s more, you’ll learn how to do it using Open Source technologies. This book is aimed at readers who already know at least the basics of HTML and have done some programming in a modern programming language before, but have not necessarily pro- grammed for the Internet or used a relational database. If you are a beginning programmer, you should still find this book useful, but it might take you a little longer to digest. We’ve tried not to leave out any basic concepts, but we do cover them at speed. The typical reader of this book is someone who wants to master PHP and MySQL for the purpose of building a large or com- mercial Web site. You might already be working in another Web development language; if so, this book should get you up to speed quickly. We wrote this book because we were tired of finding books on PHP that were basically a func- tion reference. These books are useful, but they don’t help when your boss or client has said “Go build me a shopping cart.” We have done our best to make every example useful. Many of the code samples can be directly used in your Web site, and many others can be used with minor modifications. What You Will Be Able to Achieve Using This Book Reading this book will enable you to build real-world, dynamic Web sites. If you’ve built Web sites using plain HTML, you will realize the limitations of this approach. Static content from a pure HTML Web site is just that—static. It stays the same unless you physically update it. Your users can’t interact with the site in any meaningful fashion. 01 7842 intro 3/6/01 3:33 PM Page 1 PHP AND MYSQL WEB DEVELOPMENT Using a language such as PHP and a database such as MySQL allows you to make your sites dynamic: to have them be customizable and contain real-time information. We have deliberately focused this book on real-world applications, even in the introductory chap- ters. We’ll begin by looking at a simple online ordering system, and work our way through the various parts of PHP and MySQL. We will then discuss aspects of electronic commerce and security as they relate to building a real- world Web site, and show you how to implement these aspects in PHP and MySQL. In the final section of this book, we will talk about how to approach real-world projects, and take you through the design, planning, and building of the following seven projects: • User authentication and personalization • Shopping carts • Content management systems • Web-based email • Mailing list managers • Web forums • Document generation Any of these projects should be usable as is, or can be modified to suit your needs. We chose them because we believe they represent seven of the most common Web-based applications built by programmers. If your needs are different, this book should help you along the way to achieving your goals. What Is PHP? PHP is a server-side scripting language designed specifically for the Web. Within an HTML page, you can embed PHP code that will be executed each time the page is visited. Your PHP code is interpreted at the Web server and generates HTML or other output that the visitor will see. PHP was conceived in 1994 and was originally the work of one man, Rasmus Lerdorf. It was adopted by other talented people and has gone through three major rewrites to bring us the broad, mature product we see today. As of January 2001, it was in use on nearly five million domains worldwide, and this number is growing rapidly. You can see the current number at http://www. php.net/usage.php PHP is an Open Source product. You have access to the source code. You can use it, alter it, and redistribute it all without charge. PHP originally stood for Personal Home Page, but was changed in line with the GNU recursive naming convention (GNU = Gnu’s Not Unix) and now stands for PHP Hypertext Preprocessor. The current major version of PHP is 4. This version has seen some major improvements to the language, discussed in the next section. 2 01 7842 intro 3/6/01 3:33 PM Page 2 INTRODUCTION The home page for PHP is available at http://www.php.net The home page for Zend is at http://www.zend.com What’s New In PHP Version 4? If you have used PHP before, you will notice a few important improvements in version 4. In this new version • PHP 4 is much faster than previous versions because it uses the new Zend Engine. If you need even higher performance, you can obtain the Zend Optimizer, Zend Cache, or Zend Compiler from http://www.zend.com. • You have always been able to use PHP as an efficient module for the Apache server. With this new version, you can install PHP as an ISAPI module for Microsoft’s Internet Information Server. • Session support is now built in. In previous versions, you needed to install the PHPlib add- on for session control or write your own. What Is MySQL? MySQL (pronounced My-Ess-Que-Ell) is a very fast, robust, relational database management sys- tem (RDBMS). A database enables you to efficiently store, search, sort, and retrieve data. The MySQL server controls access to your data to ensure that multiple users can work with it concur- rently, to provide fast access to it, and ensure that only authorized users can obtain access. Hence, MySQL is a multi-user, multi-threaded server. It uses SQL (Structured Query Language), the stan- dard database query language worldwide. MySQL has been publicly available since 1996, but has a development history going back to 1979. It has now won the Linux Journal Readers’ Choice Award three years running. MySQL is now available under an Open Source license, but commercial licenses are also available if required. Why Use PHP and MySQL? When setting out to build an e-commerce site, there are many different products that you could use. You will need to choose hardware for the Web server, an operating system, Web server software, a database management system, and a programming or scripting language. Some of these choices will be dependent on the others. For example, not all operating systems will run on all hardware, not all scripting languages can connect to all databases, and so on. In this book, we do not pay much attention to your hardware, operating system, or Web server software. We don’t need to. One of the nice features of PHP is that it is available for Microsoft Windows, for many versions of UNIX, and with any fully-functional Web server. MySQL is similarly versatile. 3 01 7842 intro 3/6/01 3:33 PM Page 3 PHP AND MYSQL WEB DEVELOPMENT To demonstrate this, the examples in this book have been written and tested on two popular setups: • Linux using the Apache Web server • Microsoft Windows 2000 using Microsoft Internet Information Server (IIS) Whatever hardware, operating system, and Web server you choose, we believe you should seri- ously consider using PHP and MySQL. Some of PHP’s Strengths Some of PHP’s main competitors are Perl, Microsoft Active Server Pages (ASP), Java Server Pages (JSP), and Allaire Cold Fusion. In comparison to these products, PHP has many strengths including the following: • High performance • Interfaces to many different database systems • Built-in libraries for many common Web tasks • Low cost • Ease of learning and use • Portability • Availability of source code A more detailed discussion of these strengths follows. Performance PHP is very efficient. Using a single inexpensive server, you can serve millions of hits per day. Benchmarks published by Zend Technologies (http://www.zend.com) show PHP outperforming its competition. Database Integration PHP has native connections available to many database systems. In addition to MySQL, you can directly connect to PostgreSQL, mSQL, Oracle, dbm, filePro, Hyperwave, Informix, InterBase, and Sybase databases, among others. Using the Open Database Connectivity Standard (ODBC), you can connect to any database that provides an ODBC driver. This includes Microsoft products, and many others. Built-in Libraries Because PHP was designed for use on the Web, it has many built-in functions for performing many useful Web-related tasks. You can generate GIF images on-the-fly, connect to other net- work services, send email, work with cookies, and generate PDF documents, all with just a few lines of code. 4 01 7842 intro 3/6/01 3:33 PM Page 4 . xxi PHP AND MYSQL WEB DEVELOPMENT Problems with Headers 777 Extending the Project 778 Further Reading 778 PART VI Appendixes 779 A Installing PHP 4 and MySQL 781 Running PHP as a CGI Interpreter. a PDF Certificate from a Template 762 Generating a PDF Document Using PDFlib 765 A Hello World Script for PDFlib 766 Generating Our Certificate with PDFlib 770 xxi 00 7842 FM 3/ 6/01 3: 38 PM Page. 782 Installing Apache, PHP, and MySQL Under UNIX 7 83 Apache and mod_SSL 787 httpd.conf File—Snippets 790 Is SSL Working? 792 Installing Apache, PHP, and MySQL Under Windows 7 93 Installing MySQL Under