Daily Summary of New Comments for Post Authors

A PHP snippet for Daily Summary of New Comments for Post Authors.

function send_daily_comment_summary() {
    global $wpdb;

    // Get all authors with published posts.
    $authors = get_users(array('who' => 'authors'));

    foreach ($authors as $author) {
        // Get new comments for the author's posts in the last 24 hours.
        $comments = $wpdb->get_results($wpdb->prepare("
            SELECT comment_author, comment_content, comment_post_ID
            FROM $wpdb->comments
            WHERE user_id != %d 
              AND comment_date >= DATE_SUB(NOW(), INTERVAL 1 DAY)
              AND comment_post_ID IN (
                  SELECT ID FROM $wpdb->posts WHERE post_author = %d
              )
              AND comment_approved = 1
        ", $author->ID, $author->ID));

        // If there are new comments, prepare the email.
        if ($comments) {
            $subject = "Daily Comment Summary for Your Posts";
            $message = "Here are the new comments on your posts from the past 24 hours:\n\n";

            foreach ($comments as $comment) {
                $post_title = get_the_title($comment->comment_post_ID);
                $comment_excerpt = wp_trim_words($comment->comment_content, 15);
                $message .= "* {$comment->comment_author} commented on \"$post_title\": \"$comment_excerpt\"\n";
            }

            $headers = array('Content-Type: text/plain; charset=UTF-8');
            wp_mail($author->user_email, $subject, $message, $headers);
        }
    }
}

// Schedule this to run daily.
if (!wp_next_scheduled('send_daily_comment_summary_hook')) {
    wp_schedule_event(time(), 'daily', 'send_daily_comment_summary_hook');
}
add_action('send_daily_comment_summary_hook', 'send_daily_comment_summary');

function send_daily_comment_summary() {
    global $wpdb;

    // Get all authors with published posts.
    $authors = get_users(array('who' => 'authors'));

    foreach ($authors as $author) {
        // Get new comments for the author's posts in the last 24 hours.
        $comments = $wpdb->get_results($wpdb->prepare("

            SELECT comment_author, comment_content, comment_post_ID
            FROM $wpdb->comments
            WHERE user_id != %d 
              AND comment_date >= DATE_SUB(NOW(), INTERVAL 1 DAY)
              AND comment_post_ID IN (
                  SELECT ID FROM $wpdb->posts WHERE post_author = %d
              )
              AND comment_approved = 1
        ", $author->ID, $author->ID));

        // If there are new comments, prepare the email.
        if ($comments) {
            $subject = "Daily Comment Summary for Your Posts";
            $message = "Here are the new comments on your posts from the past 24 hours:\n\n";

            foreach ($comments as $comment) {
                $post_title = get_the_title($comment->comment_post_ID);
                $comment_excerpt = wp_trim_words($comment->comment_content, 15);
                $message .= "* {$comment->comment_author} commented on \"$post_title\": \"$comment_excerpt\"\n";
            }

            $headers = array('Content-Type: text/plain; charset=UTF-8');
            wp_mail($author->user_email, $subject, $message, $headers);
        }
    }
}

// Schedule this to run daily.
if (!wp_next_scheduled('send_daily_comment_summary_hook')) {
    wp_schedule_event(time(), 'daily', 'send_daily_comment_summary_hook');
}
add_action('send_daily_comment_summary_hook', 'send_daily_comment_summary');