Sắp xếp sản phẩm hết hàng xuống cuối danh sách sản phẩm của woocommerce

/*
 * Order by stock status
 * Shared by levantoan.com
 * */
add_filter('posts_clauses', 'devvn_order_by_stock_status', 2000);
function devvn_order_by_stock_status($posts_clauses) {
    global $wpdb;
    if (is_woocommerce() && (is_shop() || is_product_category() || is_product_tag())) {
        if (strpos($posts_clauses['where'], "wp_posts.post_type = 'product'") !== false) {
            $posts_clauses['join'] .= " INNER JOIN $wpdb->postmeta istockstatus ON ($wpdb->posts.ID = istockstatus.post_id) ";
            $posts_clauses['orderby'] = " istockstatus.meta_value ASC, " . $posts_clauses['orderby'];
            $posts_clauses['where'] = " AND istockstatus.meta_key = '_stock_status' AND istockstatus.meta_value <> '' " . $posts_clauses['where'];
        }
    }
    return $posts_clauses;
}