comment_closed
comment_closed is an action run when someone tries to submit a comment to an entry where comments are closed.
Context:
File: wp-comments-post.php
$status = $wpdb->get_row("SELECT post_status, comment_status FROM $wpdb->posts WHERE ID = '$comment_post_ID'");
if ( empty($status->comment_status) ) {
do_action('comment_id_not_found', $comment_post_ID);
exit;
} elseif ( 'closed' == $status->comment_status ) {
do_action('comment_closed', $comment_post_ID);
die( __('Sorry, comments are closed for this item.') );
} elseif ( 'draft' == $status->post_status ) {
do_action('comment_on_draft', $comment_post_ID);
exit;
}
This hook is an action which means that it primarily acts as an event trigger, instead of a content filter. This is a semantic difference, but it will help you to remember what this hook does if you use it like this: add_action('comment_closed', 'your_function');