Adicionar permissão para editor criar usuários, exceto para função de administrador

Eu estava procurando uma solução onde um usuário com a função de “Editor” pudesse criar/editar usuários, sem que fosse necessário alterar sua função para “Administrador”.

A solução é bem simples, basta copiar e colar o seguinte código no arquivo functions.php do seu tema:

// Customizes 'Editor' role to have the ability to modify menus, add new users
// and more.
class Custom_Admin {
// Add our filters
public function __construct(){
// Allow editor to edit theme options (ie Menu)
add_action('init', array($this, 'init'));
add_filter('editable_roles', array($this, 'editable_roles'));
add_filter('map_meta_cap', array($this, 'map_meta_cap'), 10, 4);
}

public function init() {
if ($this->is_client_admin()) {
// Disable access to the theme/widget pages if not admin
add_action('admin_head', array($this, 'modify_menus'));
add_action('load-themes.php', array($this, 'wp_die'));
add_action('load-widgets.php', array($this, 'wp_die'));
add_action('load-customize.php', array($this, 'wp_die'));

add_filter('user_has_cap', array($this, 'user_has_cap'));
}
}

public function wp_die() {
_default_wp_die_handler(__('You do not have sufficient permissions to access this page.'));
}

public function modify_menus()
{
remove_submenu_page( 'themes.php', 'themes.php' ); // hide the theme selection submenu
remove_submenu_page( 'themes.php', 'widgets.php' ); // hide the widgets submenu

// Appearance Menu
global $menu;
global $submenu;
if (isset($menu[60][0])) {
$menu[60][0] = "Menus"; // Rename Appearance to Menus
}
unset($submenu['themes.php'][6]); // Customize
}

// Remove 'Administrator' from the list of roles if the current user is not an admin
public function editable_roles( $roles ){
if( isset( $roles['administrator'] ) && !current_user_can('administrator') ){
unset( $roles['administrator']);
}
return $roles;
}

public function user_has_cap( $caps ){
$caps['list_users'] = true;
$caps['create_users'] = true;

$caps['edit_users'] = true;
$caps['promote_users'] = true;

$caps['delete_users'] = true;
$caps['remove_users'] = true;

$caps['edit_theme_options'] = true;
return $caps;
}

// If someone is trying to edit or delete and admin and that user isn't an admin, don't allow it
public function map_meta_cap( $caps, $cap, $user_id, $args ){
// $args[0] == other_user_id
foreach($caps as $key => $capability)
{
switch ($cap)
{
case 'edit_user':
case 'remove_user':
case 'promote_user':
if(isset($args[0]) && $args[0] == $user_id) {
break;
}
else if(!isset($args[0])) {
$caps[] = 'do_not_allow';
}
// Do not allow non-admin to edit admin
$other = new WP_User( absint($args[0]) );
if( $other->has_cap( 'administrator' ) ){
if(!current_user_can('administrator')){
$caps[] = 'do_not_allow';
}
}
break;
case 'delete_user':
case 'delete_users':
if( !isset($args[0])) {
break;
}
// Do not allow non-admin to delete admin
$other = new WP_User(absint($args[0]));
if( $other->has_cap( 'administrator' ) ){
if(!current_user_can('administrator')){
$caps[] = 'do_not_allow';
}
}
break;
break;
}
}
return $caps;
}

// If current user is called admin or administrative and is an editor
protected function is_client_admin() {
$current_user = wp_get_current_user();
$is_editor = isset($current_user->caps['editor']) ? $current_user->caps['editor'] : false;
return ($is_editor);
}
}
new Custom_Admin();