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

Deleting custom tables on plugin removal

It is always a good practice for plugins to provide an uninstallation procedure to remove content that they added to a website's database or filesystem. When dealing with custom database tables, all records should be dropped along with the table itself when a website administrator decides to delete a plugin.

This recipe shows how to implement a data removal script to delete the bug storage table that was created in the previous recipe.

Getting ready

You should have already followed the Creating new database tables recipe to have an existing table to remove. Alternatively, you can get the resulting code (Chapter 8/ch8-bug-tracker/ch8-bug-tracker-v1-1.php) from the code bundle and rename the file as ch8-bug-tracker.php.

How to do it...

  1. Navigate to the WordPress plugin directory of your development installation.
  2. Create a text file called uninstall.php in the ch8-bug-tracker directory and open it in a code editor.
  3. Start the new script with the standard <...