Book Image

WordPress 3 Plugin Development Essentials

Book Image

WordPress 3 Plugin Development Essentials

Overview of this book

WordPress is one of the most popular platforms for building blogs and general websites. By learning how to develop and integrate your own plugins, you can add functionality and extend WordPress in any way imaginable. By tapping into the additional power and functionality that plugins provide, you can make your site easier to administer, add new features, or even alter the very nature of how WordPress works. Covering WordPress version 3, this book makes it super easy for you to build a variety of plugins.WordPress 3 Plugin Development Essentials is a practical hands-on tutorial for learning how to create your own plugins for WordPress. Using best coding practices, this book will walk you through the design and creation of a variety of original plugins.WordPress 3 Plugin Development Essentials focuses on teaching you all aspects of modern WordPress development. The book uses real and published WordPress plugins and follows their creation from the idea to the finishing touches in a series of easy-to-follow and informative steps. You will discover how to deconstruct an existing plugin, use the WordPress API in typical scenarios, hook into the database, version your code with SVN, and deploy your new plugin to the world.Each new chapter introduces different features of WordPress and how to put them to good use, allowing you to gradually advance your knowledge. WordPress 3 Plugin Development Essentials is packed with information, tips, and examples that will help you gain comfort and confidence in your ability to harness and extend the power of WordPress via plugins.
Table of Contents (19 chapters)
WordPress 3 Plugin Development Essentials
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Understanding the Includes


When you activate a plugin, the name of the file containing the information header is stored in the WordPress database. Each time a page is requested, WordPress goes through a laundry list of PHP files it needs to load, so activating a plugin ensures that your own files are on that list. To help illustrate this concept, let's break WordPress again.

Exercise – parse errors

Try the following exercise:

  1. Ensure that the "Hello Dolly" plugin is active.

  2. Open the /wp-content/plugins/hello.php file in your text editor.

  3. Immediately before the line that contains function hello_dolly_get_lyric, type in some gibberish text, such as "asdfasdf" and save the file.

  4. Reload the plugins page in your browser.

  5. This should generate a parse error, something like:

    Parse error: syntax error, unexpected T_FUNCTION in /path/to/wordpress/html/wp-content/plugins/hello.php on line 16

Yikes! Your site is now broken. Why did this happen? We introduced errors into the plugin's main file (hello.php), so...