使用WooCommerce按产品筛选订单显示Woocommerce中的产品类别

Question

我正在使用WooCommerce按产品过滤订单，但此插件将在产品的产品页面上显示产品过滤器。但我想展示产品的类别。 我该怎么办？

if ( ! defined( 'WPINC' ) ) die;

class FOA_Woo_Filter_Orders_by_Product{
    private static $instance = null;

    private function __construct() {
        if ( !in_array( 'woocommerce/woocommerce.php', apply_filters( 'active_plugins', get_option( 'active_plugins' ) ) ) || !is_admin() ){
            return;
        }
        add_action( 'init', array( $this, 'load_textdomain' ) );
        add_action( 'restrict_manage_posts', array( $this, 'product_filter_in_order' ), 50  );
        add_action( 'posts_where', array( $this, 'product_filter_where' ));
        add_action( 'admin_enqueue_scripts', array( $this, 'scripts_and_styles' ));
    }

    public static function instance() {
        if ( null == self::$instance ) {
            self::$instance = new self;
        }
        return self::$instance;
    }

    // Textdomain
    public function load_textdomain(){
        load_plugin_textdomain( 'woocommerce-filter-orders-by-product', false, dirname( plugin_basename(__FILE__) ) . '/languages/' );
    }

    // Display dropdown
    public function product_filter_in_order(){
        global $typenow, $wpdb;

        if ( 'shop_order' != $typenow ) {
            return;
        }
        $status = apply_filters( 'wfobp_product_status', 'publish' );
        $sql    = "SELECT ID,post_title FROM $wpdb->posts WHERE post_type = 'product'";
        $sql   .= ( $status == 'any' ) ? '' : " AND post_status = '$status'";
        $all_posts = $wpdb->get_results($sql, ARRAY_A);

        $values = array();
        foreach ($all_posts as $all_post) {
            $values[$all_post['ID']] = $all_post['post_title'];
        }
        ?>
        <span id="foa_order_product_filter_wrap">
            <select name="foa_order_product_filter" id="foa_order_product_filter">
            <option value=""><?php _e('All products', 'woocommerce-filter-orders-by-product'); ?></option>
            <?php
                $current_v = isset($_GET['foa_order_product_filter'])? $_GET['foa_order_product_filter']:'';
                foreach ($values as $key => $title) {
                    printf
                        (
                            '<option value="%s"%s>%s</option>',
                            $key,
                            $key == $current_v? ' selected="selected"':'',
                            $title
                        );
                    }
            ?>
            </select>
            <div id="fuzzSearch">
                <div id="fuzzNameContainer">
                    <span class="fuzzName"></span>
                    <span class="fuzzArrow"></span>
                </div>
                <div id="fuzzDropdownContainer">
                    <input type="text" value="" class="fuzzMagicBox" placeholder="<?php _e('Search...', 'woocommerce-filter-orders-by-product'); ?>" />
                    <ul id="fuzzResults">
                    </ul>
                </div>
            </div>
        </span>
        <script type="text/javascript">
            jQuery('#foa_order_product_filter').fuzzyDropdown({
              mainContainer: '#fuzzSearch',
              arrowUpClass: 'fuzzArrowUp',
              selectedClass: 'selected',
              enableBrowserDefaultScroll: true
            });
       </script>
        <?php
    }

    // modify where clause in query
    public function product_filter_where( $where ) {
        if( is_search() ) {
            global $wpdb;
            $t_posts = $wpdb->posts;
            $t_order_items = $wpdb->prefix . "woocommerce_order_items";  
            $t_order_itemmeta = $wpdb->prefix . "woocommerce_order_itemmeta";

            if ( isset( $_GET['foa_order_product_filter'] ) && !empty( $_GET['foa_order_product_filter'] ) ) {
                $product = intval($_GET['foa_order_product_filter']);
                $where .= " AND $product IN (SELECT $t_order_itemmeta.meta_value FROM $t_order_items LEFT JOIN $t_order_itemmeta on $t_order_itemmeta.order_item_id=$t_order_items.order_item_id WHERE $t_order_items.order_item_type='line_item' AND $t_order_itemmeta.meta_key='_product_id' AND $t_posts.ID=$t_order_items.order_id)";
            }
        }
        return $where;
    }
    // scripts_and_styles
    public function scripts_and_styles(){
        wp_enqueue_script( 'foa-fuzzy-script', plugin_dir_url( __FILE__ ).'fuzzy-dropdown.min.js', array( 'jquery' ) );
        wp_enqueue_style( 'foa-fuzzy-styles', plugin_dir_url( __FILE__ ).'style.css' );
    }
}