comment exiger une longueur minimale de commentaire dans wordpress

1<?php
2add_filter( 'preprocess_comment', 'minimal_comment_length' );
3function minimal_comment_length( $commentdata ) {
4     $minimalCommentLength = 20;
5      if ( strlen( trim( $commentdata['comment_content'] ) ) &lt; $minimalCommentLength ){
6       wp_die( 'All comments must be at least ' . $minimalCommentLength . ' characters long.' );
7     }
8     return $commentdata;
9}
10?>