trackback_response example

// Escape values to use in the trackback. $title     = wp_slash( $title );
$excerpt   = wp_slash( $excerpt );
$blog_name = wp_slash( $blog_name );

if ( is_single() || is_page() ) {
    $post_id = $posts[0]->ID;
}

if ( ! isset( $post_id ) || ! (int) $post_id ) {
    trackback_response( 1, __( 'I really need an ID for this to work.' ) );
}

if ( empty( $title ) && empty( $trackback_url ) && empty( $blog_name ) ) {
    // If it doesn't look like a trackback at all.     wp_redirect( get_permalink( $post_id ) );
    exit;
}

if ( ! empty( $trackback_url ) && ! empty( $title ) ) {
    /** * Fires before the trackback is added to a post. * * @since 4.7.0 * * @param int $post_id Post ID related to the trackback. * @param string $trackback_url Trackback URL. * @param string $charset Character set. * @param string $title Trackback title. * @param string $excerpt Trackback excerpt. * @param string $blog_name Site name. */