Users sorting option

Here is my own change of your code. In my case i was needed to sort them by display name.

public function get_all_staff( $args = null ) {
$meta = array(
‘meta_query’ => array(
array(
‘key’ => ATTMGR::PLUGIN_ID.’_ex_attr_staff’,
‘value’ => 1,
‘compare’ => ‘=’
),
),

/**
* My addon
*/

‘meta_key’ => ‘first_name’,
‘orderby’ => ‘display_name’,
‘order’ => ‘ASC’

);
$user_query = new WP_User_Query( $meta );
$users = $user_query->results;
$staff = array();
if ( ! empty( $users ) ) {
foreach ( $users as $u ) {
if ( ! empty( $u->ID ) ) {
$user = new ATTMGR_User( $u->ID );
//if ( $user->is_staff() ) {
$staff[] = $user;
//}
}
}
}
return $staff;
}