Book Image

WordPress Plugin Development Cookbook - Third Edition

By : Yannick Lefebvre
Book Image

WordPress Plugin Development Cookbook - Third Edition

By: Yannick Lefebvre

Overview of this book

WordPress is one of the most widely used, powerful, and open content management systems (CMSs). Whether you're a site owner trying to find the right extension, a developer who wants to contribute to the community, or a website developer working to fulfill a client's needs, learning how to extend WordPress' capabilities will help you to unleash its full potential. This book will help you become familiar with API functions to create secure plugins with easy-to-use administration interfaces. This third edition contains new recipes and up-to-date code samples, including new chapters on creating custom blocks for the block editor and integrating data from external sources. From one chapter to the next, you’ll learn 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, followed by recipes covering how to design administration panels, enhance the post editor with custom fields, store custom data, and even create custom blocks. You'll safely incorporate dynamic elements into web pages using scripting languages, learn how to integrate data from external sources, 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 (15 chapters)

Removing plugin data on deletion

As with any piece of software, it is quite possible that users might decide to remove a plugin from their WordPress installation if they no longer require the functionality that it provides, or they have found an alternative that they prefer.

When this happens, the plugin author must decide whether all of the configuration data stored in the site's database should be left in place, making it easier to re-install the plugin down the road, or to remove all of this information, leaving a clean database behind.

Getting ready

You should have already followed the Storing user settings using arrays recipe to have options data ready for deletion, and the resulting plugin should still be active on your development site. Alternatively, you can get the resulting code (ch3/ch2-page-header-output/ch2-page-header-output-v3.php) from the book's GitHub page. You should rename the ch2-page-header-output-v3.php file as ch2-page-header-output.php and...