As we saw in Chapter 2, Plugin Framework Basics, it is very easy for a plugin to register custom functions with action and filter hooks to change or augment the way WordPress renders web pages. That being said, some of the examples covered in Chapter 2, Plugin Framework Basics, have limitations when it comes to dealing with custom user information, such as the inability to easily specify a Google Analytics account number.

To make plugins easy to use for a wide audience, it is usually important to create one or more administration pages where users will be able to provide details that are specific to their installation, enter information on external accounts, and customize some of the aspects of the plugin's functionality. As an example, the Akismet plugin, provided in default WordPress installations, offers a configuration page that can be found under the Settings | Akismet configuration menu. Thankfully, WordPress has a rich set of functions that allows plugin developers to easily put together configuration pages that will seamlessly blend with the rest of the administrative panels.

This chapter covers how to use the WordPress Options Application Programming Interface (API) functions to store and access user options in the site database. It then goes on to explain how to create custom dialogs to provide users with complete control over the configuration of the plugins that you create.