Professional WordPress Plugin Development, 2nd Edition

9Users and User Data

WHAT'S IN THIS CHAPTER?

• Working with users and user functions
• Adding, updating, and retrieving user data
• Understanding roles and capabilities
• Limiting access with user permissions
• Building custom roles and capabilities

CODE DOWNLOADS FOR THIS CHAPTER

The code downloads for this chapter are found at www.wiley.com/go/prowordpressdev2e on the Downloads tab.

When WordPress was first launched more than 15 years ago, it was primarily a blogging system used by individuals. Over the years, it has become more of a content management system (CMS) that powers nearly any type of site conceivable. A large part of what is possible now centers on its user system. Today, WordPress powers websites with thousands, hundreds of thousands, and even millions of users.

Knowing how WordPress handles users is now an important tool in any plugin developer's toolbox. You will deal with various user scenarios in many of your plugins. Perhaps, more important, understanding the roles and capabilities system is paramount to developing a solid and secure plugin. Roles and capabilities define what users can do within individual sites. They represent the permissions system for WordPress.

People use WordPress for private membership sites, social networks, online journalism, medical databases, education centers, and much more. Each of these types of websites might require plugins to handle users and permissions. When creating plugins for these sites, it is often important ...