Unlike the get_posts() and get_pages() functions within WordPress, get_users() doesn’t provide a way to return a random selection of users (the results can only be sorted by ‘nicename’, ‘email’, ‘url’, ‘registered’, ‘display_name’, or ‘post_count’). For several projects, usually for sidebar widgets, theres been a need to return a randomly sorted sub-set of users, so I wrote the following custom function:
if ( !function_exists( 'get_random_users' ) ) {
function get_random_users( $args = array() ) {
$random_users = array();
$number = 10;
$defaults = array( 'number' => $number, 'exclude_administrators' => FALSE );
$args = wp_parse_args( $args, $defaults );
$number = $args['number'];
unset( $args['number'] );
if ( $args['exclude_administrators'] == TRUE ) {
$administrators = get_users( array( 'role' => 'administrator' ) );
if ( $administrators && !is_wp_error( $administrators ) ) {
$exclude = array();
foreach( $administrators as $user ) {
$exclude[] = $user->ID;
}
$args['exclude'] = $exclude;
}
}
$users = get_users( $args );
if ( $users && !is_wp_error( $users ) ) {
$total_users = count( $users );
$number = ( $total_users > $number ) ? $number: $total_users;
if ( $total_users == 1 ) {
$random_users = $users;
} elseif ( $total_users > 1 ) {
shuffle( $users );
$random_users = array_slice( $users, 0, $number );
}
}
return $random_users;
}
}
Essentially it works and accepts the same parameters as get_users(), but I have included an option that allows you to exclude Administrators from the returned array. I’m sure the code can be improved – and I probably will do when I get the chance, but for now it does the job.
Alternatively, the following two lines of code, added into the wp-includes/user.php file at line 446, would remove the need for the above function and allow ‘rand’ to be a valid value for the ‘orderby’ parameter.
} elseif ( 'rand' == $qv['orderby'] ) {
$orderby = 'RAND()';
But I would never condone editing the core WordPress files.