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

Implementing the widget display function

For all of the widget creation work that we have done so far, our new creation does not display any content on the website yet. When displaying an area that contains widgets, WordPress tries to call a method named widget for each user-selected widget to output the desired content to the browser.

This recipe shows how to implement a widget method to display a list of recent book reviews when the widget is instantiated in a sidebar.

Getting ready

You should have already followed the Validating configuration options recipe to have a starting point for this recipe. Alternatively, you can get the resulting code (Chapter 10/ch10-book-review-widget/ch10-book-review-widget-v3.php) from the code bundle and rename the file as ch10-book-review-widget.php.

How to do it...

  1. Navigate to the WordPress plugin directory of your development installation.
  2. Navigate to the ch10-book-review-widget directory and edit ch10-book-review-widget.php.
  3. Find the Book_Reviews class and...