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)

Creating a new widget in WordPress

The first step in creating a custom widget is to define its name and indicate the class that contains all of its implementation functions. We also need to specify a function to render the widget's contents. Once the new element has been registered with the system, it will immediately appear in the widget list, where users will be able to drag and drop it to their widget areas.

Getting ready

You should have already followed the Updating the page title to include custom post data using plugin filters recipe in Chapter 4, The Power of Custom Post Types, to have a starting point for this recipe. Alternatively, you can get the resulting code (ch4/ch4-book-reviews/ch4-book-reviews-v12.php) from the book's GitHub page and make sure that the Chapter 4 - Book Reviews plugin is activated.

How to do it...

Follow these steps to define a new widget that displays recent book reviews from the custom post type created in Chapter 4, The Power...