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

Safely loading jQuery onto WordPress web pages

While it might be tempting to provide your own copy of jQuery as part of a new plugin that uses the popular JavaScript library or to access a copy from the Google API website, WordPress actually provides a copy of jQuery in its installation and makes it very easy to load it.

By using the appropriate utility function to load jQuery, developers make a request to WordPress to load this library instead of doing it themselves. Once all the requests have been received, they are analyzed for duplicates and a single instance of each script is loaded to reduce the chance of conflicts between multiple copies of the same library.

This recipe shows how to load the jQuery script for use on front-facing website pages.

Getting ready

You should have access to a WordPress development environment.

How to do it...

  1. Navigate to the WordPress plugin directory of your development installation.
  2. Create a new directory called ch9-load-jquery.
  3. Navigate to the directory and create...