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

Using a local library to implement a CAPTCHA on user forms

As discussed in the previous recipe, Implementing a CAPTCHA on user forms using an online service, adding a CAPTCHA to visitor-facing forms helps reduce unwanted submissions to a website. After seeing how to integrate an online third-party service, this recipe shows how to download and integrate a local PHP script to generate and validate CAPTCHA images locally.

Getting ready

You should be running the final version of the Book Reviews plugin created in Chapter 4, The Power of Custom Post Types, and should have already followed the Sending email notifications upon new submissions recipe. Alternatively, you can get the resulting files from the code bundle (Chapter 4/ch4-book-reviews/ch4-book-reviews-v11.php and Chapter 6/ch6-book-review-user-submission/ch6-book-review-user-submission-v3.php) and rename ch6-book-review-user-submission-v3.php to ch6-book-review-user-submission.php before starting the recipe.

The GD and FreeType libraries...