Add User Role and ID as a body Class in WordPress Admin/Frontend

This is a quick guide that explains how to print the current user role as a body class in the WordPress Admin and/or the Frontend, it can also be used to print the user ID as a Class.

Why would you want to do this? Well if you have found this article then you probably already have a reason, we use it to style page elements for certain classes and even hide parts of a page to a user on both the frontend and backend. This isn’t the best method to hiding elements but can provide a temporary solution.

The function below will detect the current user and then print their role and id as a body class in the WP Admin and in the frontend of the site, for example, class="administrator user-id-1". This function will only run if the user is logged in.

/**
 * Add User Role Class to Body
 * Referenced code from http://www.studiok40.com/
 */
function print_user_classes() {
    if ( is_user_logged_in() ) {
        add_filter('body_class','class_to_body');
        add_filter('admin_body_class', 'class_to_body_admin');
    }
}
add_action('init', 'print_user_classes');

/// Add user role class to front-end body tag
function class_to_body($classes) {
    global $current_user;
    $user_role = array_shift($current_user->roles);
    $classes[] = $user_role.' ';
    return $classes;
}

/// Add user role class and user id to front-end body tag

// add 'class-name' to the $classes array
function class_to_body_admin($classes) {
    global $current_user;
    $user_role = array_shift($current_user->roles);
    /* Adds the user id to the admin body class array */
    $user_ID = $current_user->ID;
    $classes = $user_role.' '.'user-id-'.$user_ID ;
    return $classes;
    return 'user-id-'.$user_ID;
}

You can use this function in a MU plugin or as a standalone plugin or even in your theme functions.php.