16. PHP Basics: Themes and Plug-ins
WordPress is written in the Personal Home Page (PHP) scripting language, and therefore, much of what users contribute to the software in the way of themes and plug-ins is written in the same language. In this chapter, you’ll learn a little bit about the language, along with its relationship to WordPress and the MySQL database. You’ll find out where PHP fits in with theme creation. The chapter concludes with your writing WordPress plug-ins with PHP and getting them into the WordPress Plugin Directory.
PHP is the result of another lazy programmer’s effort to simplify his life. Back in 1994, Rasmus Lerdorf wanted to eliminate some of the drudgery associated with updating his personal web page. ...