Author list based on recently active

Question

My list of authors is now based on post count and I would like it to be based on recently active user. My idea was trying changing the orderby to post_date but it has no effect. Any suggestions to how I can do this? The list needs to include user photo.

<!-- users --> 
$allUsers = get_users('orderby=post_count&order=DESC');

$users = array();

foreach($allUsers as $currentUser)
{
    if(!in_array( 'subscriber', $currentUser->roles ))
    {
        $users[] = $currentUser;
    }
}

?>

<section class="content" role="main">
    <?php
        printf('<h1>%s</h1>', the_title());

        foreach($users as $user)
        {
            ?>
            <div class="author">
                <div class="authorAvatar">
                    <?php echo get_avatar( $user->user_email, '128' ); ?>
                </div>
                <div class="authorInfo">
                    <h2 class="authorName"><?php echo $user->display_name; ?></h2>
                    <p class="authorDescrption"><?php echo get_user_meta($user->ID, 'description', true); ?></p>
                    <p class="authorLinks"><a href="<?php echo get_author_posts_url( $user->ID ); ?>">View Author Links</a></p>

                    <p class="socialIcons">
                        <ul>
                            <?php
                                $website = $user->user_url;
                                if($user->user_url != '')
                                {
                                    printf('<li><a href="%s">%s</a></li>', $user->user_url, 'Website');
                                }

                                $twitter = get_user_meta($user->ID, 'twitter_profile', true);
                                if($twitter != '')
                                {
                                    printf('<li><a href="%s">%s</a></li>', $twitter, 'Twitter');
                                }

                                $facebook = get_user_meta($user->ID, 'facebook_profile', true);
                                if($facebook != '')
                                {
                                    printf('<li><a href="%s">%s</a></li>', $facebook, 'Facebook');
                                }

                                $google = get_user_meta($user->ID, 'google_profile', true);
                                if($google != '')
                                {
                                    printf('<li><a href="%s">%s</a></li>', $google, 'Google');
                                }

                                $linkedin = get_user_meta($user->ID, 'linkedin_profile', true);
                                if($linkedin != '')
                                {
                                    printf('<li><a href="%s">%s</a></li>', $linkedin, 'LinkedIn');
                                }
                            ?>
                        </ul>
                    </p>
                </div>
            </div>
            <?php
        }
    ?>
</section>
<!-- usersending --> 

Answer 1

I would take a different approach to this using a direct database query to get a list of author IDs ordered by recent posts.

global $wpdb;
$user_ids = $wpdb->get_results(
    "
    SELECT DISTINCT post_author
    FROM $wpdb->posts
    ORDER BY post_date DESC 
    "
);
if ( $user_ids ) {
    foreach ( $user_ids as $user_id ) {
        $user = get_user_by( 'id', $user_id );
        // do stuff with $user
    }
}