If you’re programming user management in WordPress there are a number of functions we have the convenience of using on the front-end. If you want to use the same functions in the back-end, though, you’ll need to include some “dependencies.”
Programming User Management in WordPress
For example, let’s say you want to use something like:
You’ll find then incorporating them onto the front-end of the site is easy. But if you want to use them in a plugin in, say, something like this:
wp_create_user( 'acme-demo-user', wp_generate_password(12, true, false), 'firstname.lastname@example.org' );
Of if you want to delete a user with a given email:
wp_delete_user( (get_user_by('email', 'email@example.com'))->ID );
Then you’ll get an error in WordPress. It’s a simple fix, though. At the top of your file – regardless of if its procedural code or a class – add the following lines:
require_once(ABSPATH . 'wp-admin/includes/user.php'); require_once(ABSPATH . 'wp-includes/pluggable.php');
This will give you access to everything you need for the above functions.
Note: If you’re only going to use one or some of the above functions, you may not need both of those files. Refer to the linked Developer Resources for more information.