Chapter 9: Leveraging JavaScript, jQuery, and AJAX Scripts

JavaScript libraries, especially the very popular jQuery library along with its numerous plugins, can do wonders in bringing a website to life with slick animations, dynamic data queries, and advanced graphical features. Unfortunately, for all of their benefits, these scripts can also be difficult to work with. For example, loading more than one copy of jQuery can destroy everything that was set up by another instance, and errors in one script usually prevent other scripts from running correctly.

WordPress' answer to this convoluted architecture is twofold. As a first step, it comes pre-packaged with a copy of jQuery and many other popular JavaScript libraries that plugin developers can use without having to load their own versions. Then, to prevent multiple copies from being loaded on a page, it offers easy-to-use functions that queue up scripts and styles to identify duplicates before rendering pages.

This chapter...