Chapter 27. Design

Topics in This Chapter

• Writing Requirements Specifications

• Writing Design Documents

• Change Management

• Modularization Using include

• FreeEnergy

• Templates

• Application Frameworks

• PEAR

• URLs Friendly to Search Engines

Building a Web site with PHP is not the same as building a static Web site. If you choose simply to sprinkle PHP code occasionally throughout the site, the effect may be minimal, of course. If you choose to use PHP to generate every page, you will find many opportunities for transforming patterns into functions. As I wrote in Chapter 26, elements such as opening and closing body tags can be put into a function or an included file. The consequence of this situation is that you no longer have just a Web site. You have a Web application.

When this happens, it becomes more important to draw upon formal development techniques. Certainly, structured design is useful when building static Web sites. The case is made plainly in Web Site Engineering by Thomas Powell. The addition of PHP makes careful design critical. PHP applications may not be mission-critical endeavors that include thousands of programmers, but there are some ideas from software engineering that can benefit small projects. I can't cover every topic of software engineering as it applies to Web applications in the context of a chapter. I recommend reading Powell's book as an excellent starting point. I also recommend Pete McBreen's Software Craftsmanship. His ideas frame the experience of PHP-powered development well.

After introducing the basics of software requirements and design, I will explore some specific design issues and solutions.