在woocommerce中，当购物车为空时，ajax添加到购物车方法不添加，如果购物车包含某些内容，则我的ajax函数会添加，但如果购物车为空，则不会添加。没有错误。

这是link.PHP添加购物车功能：

function add_custom_product_meta() {
    global $woocommerce, $wpdb;

    $item_id = isset($_POST[\'item_id\']) ? apply_filters( \'woocommerce_add_to_cart_product_id\', absint( $_POST[\'item_id\'] ) ) : FALSE;
    $quantity = empty( $_POST[\'quantity\'] ) ? 1 : wc_stock_amount( $_POST[\'quantity\'] );
    $passed_validation = apply_filters( \'woocommerce_add_to_cart_validation\', true, $item_id, $quantity );
    $product_status    = get_post_status( $item_id );

    $variation_id = isset($_POST[\'variation_id\']) ? $_POST[\'variation_id\'] : 0;
    $atributes = isset($_POST[\'atributes\']) ? $_POST[\'atributes\'] : \'Small\';
    $attribute_pa_macaroons = isset($_POST[\'attribute_pa_macaroons\']) ? $_POST[\'attribute_pa_macaroons\'] : FALSE;

    if($attribute_pa_macaroons && $passed_validation && $woocommerce->cart->add_to_cart( $item_id, $quantity, $variation_id, array( \'attribute_size\' => $atributes,  "macaroons" => $attribute_pa_macaroons))){

        //$added = $woocommerce->cart->add_to_cart( $item_id, $quantity, $variation_id, array( \'attribute_size\' => $atributes,  "macaroons" => $attribute_pa_macaroons));

        do_action( \'woocommerce_ajax_added_to_cart\', $item_id );

        if ( get_option( \'woocommerce_cart_redirect_after_add\' ) == \'yes\' ) {
            wc_add_to_cart_message( $item_id );
        }

        WC_AJAX::get_refreshed_fragments();

        echo json_encode(array(
            \'atributes\' => $atributes,
            \'macaroons\' => $attribute_pa_macaroons,
            \'product_added\' => TRUE,
            \'ajax_complete\' => TRUE,
            \'posted\' => isset($_POST[\'item_id\']) ? $woocommerce->cart : \'item_id is empty\'
        ));
        wp_die();
    }

    echo json_encode(array(
        \'product_id\' => FALSE,
        \'product_added\' => FALSE,
        \'ajax_complete\' => TRUE,
        \'posted\' => $attribute_pa_macaroons
    ));
    wp_die();
}

$.ajax({
                        type : \'post\',
                        dataType : \'json\',
                        url : woocommerce_params.ajax_url,
                        data : {
                            \'action\' : \'elephas_addtocart_box\',
                            \'item_id\' : itemID,
                            \'quantity\' : quantity,
                            \'variation_id\' : variathionID,
                            \'atributes\' : atributes,
                            \'attribute_pa_macaroons\' : itemData
                        }
                    })
                    .done(function(response){
                        if(response.ajax_complete){
                            document.location.reload(true);
                        }
                    })
                    .error(function(error){
                        console.log(error);
                    })
                    .always(function(response){
                        if(response.ajax_complete){
                            document.location.reload(true);
                        }
                    });