PHP 和负值

Question

我有以下金额

$item_shipping_cost += (float) $this->get_fee( $this->fee, $item_shipping_cost ) * (int) $product_data['quantity'];

这加起来是这样的：

产品价格 + 商品运费 + 费用 * 数量

因此，如果产品价格设置为 1.00 英镑，商品运费设置为 1.00 英镑，费用为 0.50 英镑，而我想要 2 件商品，则总费用为 4.00 英镑。 但是，我想减去“费用”的值，因为我只想对附加产品收取费用。 我该怎么做？

这行代码属于 WooCommerce Shipping Per Product 插件。 完整的代码是：

class WC_Shipping_Per_Product extends WC_Shipping_Method {

const METHOD_ID = 'per_product';

/**
 * Default product shipping cost.
 *
 * @var int
 */
private $cost;

/**
 * Handling fee applied to entire order.
 *
 * @var int
 */
private $order_fee;

/**
 * Constructor.
 *
 * @param int $instance_id Instance Id for method in zone config.
 */
public function __construct( $instance_id = 0 ) {
    parent::__construct( $instance_id );
    $this->id                 = self::METHOD_ID;
    $this->method_title       = __( 'Per-product', 'woocommerce-shipping-per-product' );
    $this->method_description = __( 'Per product shipping allows you to define different shipping costs for products, based on customer location. These costs will be displayed and charged separately from any other shipping methods.', 'woocommerce-shipping-per-product' );
    $this->supports           = array(
        'shipping-zones',
        'instance-settings',
        'instance-settings-modal',
    );
    // Load the form fields.
    $this->init_form_fields();

    // Define user set variables.
    $this->title      = $this->get_option( 'title' );
    $this->tax_status = $this->get_option( 'tax_status' );
    $this->cost       = $this->get_option( 'cost' );
    $this->fee        = $this->get_option( 'fee' );
    $this->order_fee  = $this->get_option( 'order_fee' );

    // Actions.
    add_action( 'woocommerce_update_options_shipping_' . $this->id, array( $this, 'process_admin_options' ) );
}

/**
 * Initialise Gateway Settings Form Fields.
 */
public function init_form_fields() {
    $this->instance_form_fields = array(
        'title'      => array(
            'title'       => __( 'Method Title', 'woocommerce-shipping-per-product' ),
            'type'        => 'text',
            'description' => __( 'This controls the title which the user sees during checkout.', 'woocommerce-shipping-per-product' ),
            'default'     => __( 'Product Shipping', 'woocommerce-shipping-per-product' ),
            'desc_tip'    => true,
        ),
        'tax_status' => array(
            'title'       => __( 'Tax Status', 'woocommerce-shipping-per-product' ),
            'type'        => 'select',
            'description' => '',
            'default'     => 'taxable',
            'options'     => array(
                'taxable' => __( 'Taxable', 'woocommerce-shipping-per-product' ),
                'none'    => __( 'None', 'woocommerce-shipping-per-product' ),
            ),
        ),
        'cost'       => array(
            'title'       => __( 'Default Product Cost', 'woocommerce-shipping-per-product' ),
            'type'        => 'text',
            'description' => __( 'Cost excluding tax (per product) for products without defined costs. Enter an amount, e.g. 2.50. Entering an amount here will apply a global shipping cost for all products, effectively disabling all other shipping methods', 'woocommerce-shipping-per-product' ),
            'default'     => '',
            'placeholder' => __( 'Disabled, Enter an amount, e.g. 2.50.', 'woocommerce-shipping-per-product' ),
            'desc_tip'    => true,
        ),
        'fee'        => array(
            'title'       => __( 'Handling Fee (per product)', 'woocommerce-shipping-per-product' ),
            'type'        => 'text',
            'description' => __( 'Fee excluding tax. Enter an amount, e.g. 2.50, or a percentage, e.g. 5%. Leave blank to disable.', 'woocommerce-shipping-per-product' ),
            'default'     => '',
            'placeholder' => __( 'Disabled, Enter an amount, e.g. 2.50, or a percentage, e.g. 5%.', 'woocommerce-shipping-per-product' ),
            'desc_tip'    => true,
        ),
        'order_fee'  => array(
            'title'       => __( 'Handling Fee (per order)', 'woocommerce-shipping-per-product' ),
            'type'        => 'text',
            'description' => __( 'Fee excluding tax. Enter an amount, e.g. 2.50, or a percentage, e.g. 5%. Leave blank to disable.', 'woocommerce-shipping-per-product' ),
            'default'     => '',
            'placeholder' => __( 'Disabled, Enter an amount, e.g. 2.50, or a percentage, e.g. 5%.', 'woocommerce-shipping-per-product' ),
            'desc_tip'    => true,
        ),
    );
}

/**
 * Check is per product shipping is enabled for the product.
 *
 * @param array $product_data The product data form the package array.
 * @param array $package Shipping package array.
 *
 * @return bool
 */
public function is_per_product_shipping_product( array $product_data, array $package ) {
    if ( $product_data['quantity'] > 0 ) {
        if ( $product_data['data']->needs_shipping() ) {

            if ( false !== $this->calculate_product_shipping_cost( $product_data, $package ) ) {
                return true;
            }
        }
    }
    return false;
}

/**
 * Calculate the per product shipping cost if enabled for the product.
 *
 * @param array $product_data The product data form the package array.
 * @param array $package Shipping package array.
 *
 * @return float|bool
 */
private function calculate_product_shipping_cost( array $product_data, array $package ) {

    $rule               = false;
    $item_shipping_cost = 0;

    if ( $product_data['variation_id'] ) {
        $rule = woocommerce_per_product_shipping_get_matching_rule( $product_data['variation_id'], $package );
    }

    if ( false === $rule ) {
        $rule = woocommerce_per_product_shipping_get_matching_rule( $product_data['product_id'], $package );
    }

    if ( $rule ) {
        $item_shipping_cost += (float) $rule->rule_item_cost * (int) $product_data['quantity'];
        $item_shipping_cost += (float) $rule->rule_cost;
    } elseif ( '0' === $this->cost || $this->cost > 0 ) {
        // Use default shipping cost.
        $item_shipping_cost += (float) $this->cost * (int) $product_data['quantity'];
    } else {
        // NO default and nothing found - abort.
        return false;
    }

    // Fee.
    $item_shipping_cost += (float) $this->get_fee( $this->fee, $item_shipping_cost ) * (int) $product_data['quantity'];

    return $item_shipping_cost;
}

/**
 * Calculate shipping when this method is used standalone.
 *
 * @param array $package information.
 */
public function calculate_shipping( $package = array() ) {
    $_tax          = new WC_Tax();
    $taxes         = array();
    $shipping_cost = 0;

    if ( empty( $package['ship_via'] ) || ! in_array( $this->id, $package['ship_via'], true ) ) {
        return;  // must be a package mark as per product shipping in split_shipping_packages_per_product.
    }

    // This shipping method loops through products, adding up the cost.
    if ( count( $package['contents'] ) > 0 ) {
        foreach ( $package['contents'] as $item_id => $values ) {
            if ( $values['quantity'] > 0 ) {
                if ( $values['data']->needs_shipping() ) {

                    $item_shipping_cost = $this->calculate_product_shipping_cost( $values, $package );
                    $shipping_cost     += $item_shipping_cost;

                    if ( 'yes' === get_option( 'woocommerce_calc_taxes' ) && 'taxable' === $this->tax_status ) {
                        $rates      = $_tax->get_shipping_tax_rates( $values['data']->get_tax_class() );
                        $item_taxes = $_tax->calc_shipping_tax( $item_shipping_cost, $rates );

                        // Sum the item taxes.
                        foreach ( array_keys( $taxes + $item_taxes ) as $key ) {
                            $taxes[ $key ] = ( isset( $item_taxes[ $key ] ) ? $item_taxes[ $key ] : 0 ) + ( isset( $taxes[ $key ] ) ? $taxes[ $key ] : 0 );
                        }
                    }
                }
            }
        }
    }

    // Add order shipping cost + tax.
    if ( $this->order_fee ) {
        $order_fee = (float) $this->get_fee( $this->order_fee, $shipping_cost );

        $shipping_cost += $order_fee;
        if ( 'yes' === get_option( 'woocommerce_calc_taxes' ) && 'taxable' === $this->tax_status ) {
            $rates      = $_tax->get_shipping_tax_rates();
            $item_taxes = $_tax->calc_shipping_tax( $order_fee, $rates );

            // Sum the item taxes.
            foreach ( array_keys( $taxes + $item_taxes ) as $key ) {
                $taxes[ $key ] = ( isset( $item_taxes[ $key ] ) ? $item_taxes[ $key ] : 0 ) + ( isset( $taxes[ $key ] ) ? $taxes[ $key ] : 0 );
            }
        }
    }

    // Add rate.
    $this->add_rate(
        array(
            'id'    => $this->id,
            'label' => $this->title,
            'cost'  => $shipping_cost,
            'taxes' => $taxes, // We calc tax in the method.
        )
    );
}

}

Answer 1

我想你的意思是：

$item_shipping_cost -= ($product_data['quantity'] - 1) * $this->fee;

这将取消除一种产品之外的所有产品的费用。

在您的行之后添加我的代码行：

 $item_shipping_cost += (float) $this->get_fee( $this->fee, $item_shipping_cost ) * (int) $product_data['quantity'];

如果只有 1 个产品，则不会扣除任何费用。