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

Actions versus Filters


This is another confusing area in the land of WordPress plugins. What exactly is the difference between an action and a filter? Well, even if you've read through the forums and official documentation, the answers there likely left you more confused, so let's get this clarified once and for all.

Actions and filters are simply two different types of events. Remember that WordPress refers to events as "hooks". The difference between them is predicated on how WordPress handles the hook in question. Some hooks are designated as action hooks, others as filter hooks. When you link one of your functions to a filter hook, your function must accept an input and return an output because it is intended to modify or "filter" output. When you link a function to an action hook, your function is not passed input parameters, and any value returned is simply ignored. It is all a matter of how WordPress handles a given hook. On his site, Adam Brown maintains lists of all available WordPress...