WordPress® Bible

Chapter 6. Widgetizing WordPress

IN THIS CHAPTER

• Using widgets in WordPress

• Building widgets with the widget API

• Widgetizing your theme

For many end users, plugin application programming interface (API) is something that doesn't make a whole lot of difference. They know WordPress is easy to use and easy to install. They know they can write posts quickly, get maximum search engine optimization (SEO) benefit, and build traffic. Customization is what they really want, though. They know they want to change the look of their blogs without having to know any code. Fortunately, WordPress' flexible widget system does just that.

Widgets are little pieces of hypertext markup language (HTML) or JavaScript that can be placed on a site to add new functionality. As you travel the Internet, you're likely to find popular widgets in sidebars that list recent posts, comments, popular posts, ads, or blogrolls. Widgets can be anything, and since their adoption in WordPress 2.2, they have become standard fare in WordPress themes and many plugins also provide them.

Widget support used to be provided by a plugin called Sidebar Widgets. While this plugin is still available for older WordPress installs (WordPress 2.1 and earlier), it is now part of the core offering.

Widgets are installed like any other plugin. Simply install widgets in the plugins folder (/wp-content/plugins/) and activate. Like plugins, widgets can also be included in a themes functions.php file and, in that case, are automatically included ...