Book Image

WordPress Plugin Development Cookbook - Second Edition

By : Yannick Lefebvre
Book Image

WordPress Plugin Development Cookbook - Second Edition

By: Yannick Lefebvre

Overview of this book

WordPress is a popular, powerful, and open Content Management System. Learning how to extend its capabilities allows you to unleash its full potential, whether you're an administrator trying to find the right extension, a developer with a great idea to enhance the platform for the community, or a website developer working to fulfill a client's needs. This book shows readers how to navigate WordPress' vast set of API functions to create high-quality plugins with easy-to-configure administration interfaces. With new recipes and materials updated for the latest versions of WordPress 4.x, this second edition teaches you how to create plugins of varying complexity ranging from a few lines of code to complex extensions that provide intricate new capabilities. You'll start by using the basic mechanisms provided in WordPress to create plugins and execute custom user code. You will then see how to design administration panels, enhance the post editor with custom fields, store custom data, and modify site behavior based on the value of custom fields. You'll safely incorporate dynamic elements on web pages using scripting languages, and build new widgets that users will be able to add to WordPress sidebars and widget areas. By the end of this book, you will be able to create WordPress plugins to perform any task you can imagine.
Table of Contents (20 chapters)
Title Page
About the Author
About the Reviewers
Customer Feedback

Writing plugins using object-oriented PHP

So far, all plugin examples that have been covered in this chapter have been written using the procedural PHP programming style, with all the functions declared directly in the main body of the plugin and the hook registration functions having direct access to these functions.

WordPress can also be written using an object-oriented PHP approach. This recipe explains how to convert the code from the previous recipe into a class-based version of the same functionality.

Getting ready

You should have already followed the Loading a style sheet to format plugin output recipe to have a starting point for this recipe. Alternatively, you can download the resulting code (Chapter 2/ch2-private-item-text/ch2-private-item-text-v2.php) for that recipe from the Packt Publishing website (

How to do it...

  1. Log in to the administration page of your WordPress installation.
  2. Click on Plugins in the left-hand navigation menu.
  3. Check whether the...