I use the following code for getting the authors of in my multi-author blog and order them by their post count. I want to order them by the date of their last post

$authors = get_users('role=author&orderby=post_count&order=DESC');

I use the following code for getting the authors of in my multi-author blog and order them by their post count. I want to order them by the date of their last post

$authors = get_users('role=author&orderby=post_count&order=DESC');

• author
• users

• That's not possible using get_users – Tom J Nowell ♦ Commented Apr 18, 2013 at 10:27
• any way to get that? – Midhun Commented Apr 18, 2013 at 11:28

2 Answers 2

Put this in your functions.php:

function get_users_ordered_by_post_date($args = '') {
    // Prepare arguments
    if (is_string($args) && '' !== $args)
        parse_str($args, $args);
    $asc = (isset($args['order']) && 'ASC' === strtoupper($args['order']));
    unset($args['orderby']);
    unset($args['order']);

    // Get ALL users
    $users = get_users($args);
    $post_dates = array();
    if ($users) {
        // For EACH user ...
        foreach ($users as $user) {
            $ID = $user->ID;

            // ... get ALL posts (per default sorted by post_date), ...
            $posts = get_posts('author='.$ID);
            $post_dates[$ID] = '';

            // ... then use only the first (= newest) post
            if ($posts) $post_dates[$ID] = $posts[0]->post_date;
        }
    }

    // Sort dates (according to order), ...
    if (! $asc)
        arsort($post_dates);

    // ... then set up user array
    $users = array();
    foreach ($post_dates as $key => $value) {
        // $user = get_userdata($key);
        // $users[] = $user->ID;
        $users[] = get_userdata($key);
    }
    return $users;
}

The above function returns an array of WP_User objects.

// EDIT: the function now supports an args parameter (either string or array). The output is ordered with respect to order=DESC and order=ASC. The order_by parameter is remove (we want to order by last post date anyway), all other parameters are passed to get_users.

Now, you can use the function like so:

get_users_ordered_by_post_date();

or

get_users_ordered_by_post_date('role=author');

or

// order by OLDEST post first
get_users_ordered_by_post_date('role=administrator&order=ASC');

In case someone is using this (like me), here's an updated version. I believe this is quicker since it doesn't require get_userdata() on each post.

function get_users_ordered_by_post_date_dev($args = '') {
  // Prepare arguments
  if (is_string($args) && '' !== $args)
      parse_str($args, $args);
  $asc = (isset($args['order']) && 'ASC' === strtoupper($args['order']));
  unset($args['orderby']);
  unset($args['order']);
  //Date = today
  $today = date( 'Y-m-d' );
  // Get ALL users
  date_default_timezone_set('America/New_York');
  $users = get_users($args);
  $post_dates = array();
  if ($users) {
    // For EACH user ...
    foreach ($users as $user) {
        $ID = $user->ID;
        // ... get ALL posts (per default sorted by post_date), ...
        $posts = get_posts(
          array(
            'author' => $ID,
            'date_query' => array(
              'year'          => (int)date('Y'),
              'month'         => (int)date('n'),
              'day'           => (int)date('j'),
              'compare'       => '=',
              'column'        => 'post_date',
            )
          )
        );
        if ($posts) $post_dates[$posts[0]->post_date] = [
          'author' => $user,
          'post' => $posts[0]
        ];
    }
    if (! $asc){
        krsort($post_dates);
    }else{
        ksort($post_dates);
    }
    return $post_dates;
  }
}

The big change is here:

...
    if ($posts) $post_dates[$posts[0]->post_date] = [
          'author' => $user,
          'post' => $posts[0]
        ];
    }
    if (! $asc){
        krsort($post_dates);
    }else{
        ksort($post_dates);
    }
    return $post_dates;

I'm using the post dates as the key in $post_dates (Assoc Array). And depending on the argument 'ASC' will be ordered ascending or descending.

One thing to consider is that the resulting Assoc Array will contain both the WP_Post (under ['post']) and WP_User (under ['author']).