Well I have come up with 2 solutions.
Solution 1 – foreach loop and verify each user
This one is based off of @GhostToast’s solution, but with updated WordPress functions
//new query with default args
$author_query = new WP_User_Query();
// Get the results
$authors = $author_query->get_results();
if( $authors ) {
foreach( $authors as $author ) {
if ( count_user_posts( $author->id ) >= 1 ) {
echo $author->display_name . '</br>';
}
}
} else {
echo "no users found";
}
Solution 2 – fancy pants pre_user_query action
This is what I was thinking of when I posted my question once I found the pre_user_query action in the WP_User_Query class. If you pass in post_count as your orderby parameter then some fancy SQL querying that I never would’ve figured out on my own happens to join the proper tables together. So what I did was copy that join statement and add it on to my own. This would be better if I could check for its presence first before adding it… perhaps I will use a string match in the future. But for now since I am the one setting up the query I know it isn’t there and I just won’t worry about it yet. So the code turned out like so:
function authors_with_posts( $query ) {
if ( isset( $query->query_vars['query_id'] ) && 'authors_with_posts' == $query->query_vars['query_id'] ) {
$query->query_from = $query->query_from . ' LEFT OUTER JOIN (
SELECT post_author, COUNT(*) as post_count
FROM wp_posts
WHERE post_type = "post" AND (post_status = "publish" OR post_status = "private")
GROUP BY post_author
) p ON (wp_users.ID = p.post_author)';
$query->query_where = $query->query_where . ' AND post_count > 0 ';
}
}
add_action('pre_user_query','authors_with_posts');
and then to use it
$args = ( array( 'query_id' => 'authors_with_posts' ) );
$author_query = new WP_User_Query( $args );
The idea for a query_id parameter is from An Introduction to WP_User_Class
Which is also just a very good reference on WP_User_Query