Silverstripe 4银店核心PayPal Express：运费税项配置及含税价展示问题

1. Where are Shipping-Costs (Simple Shipping) and FlatTax defined? #

Both are core components of the silvershop-core module, with their logic and configuration managed as follows:

• Simple Shipping: The class lives at SilverShop\Model\Modifiers\Shipping\Simple. You can set its behavior (default cost, eligible countries, etc.) directly in your shop.yml file. For example:

  SilverShop\Model\Modifiers\Shipping\Simple:
    default_cost: 5.90
    allowed_countries:
      - AT
      - DE
  

  If you need custom shipping rules, you can create a subclass of this class in your project and override methods to fit your needs.

• FlatTax: The class is SilverShop\Model\Modifiers\Tax\FlatTax. Key settings like tax rate and display label are configured in shop.yml too:

  SilverShop\Model\Modifiers\Tax\FlatTax:
    rate: 0.15 # 15% tax rate
    label: "VAT"
  

  The tax calculation logic is built into this class, but you can extend it if you need more complex tax rules.

2. How to display brutto (tax-inclusive) prices on the frontend? #

SilverShop has built-in methods to pull tax-inclusive prices directly from your Product objects. Here's how to implement this:

• In your frontend templates (e.g., themes/yourtheme/templates/SilverShop/Product/Product.ss), replace the standard price display with the PriceWithTax() method. For example:

  <div class="product-price">
    $Product.PriceWithTax.Nice
  </div>
  

  The .Nice formatter will output the price with the correct currency symbol (like €14.84 for your €12.90 net price plus 15% tax).
• Double-check your FlatTax configuration in shop.yml to ensure the tax rate is accurate—this method relies on active modifiers to calculate the correct inclusive price.

3. How to display tax-inclusive prices on the checkout page? #

The checkout page uses the Order object, which automatically applies all modifiers (tax, shipping) during the checkout flow. You can use these built-in methods to show tax-inclusive values in your checkout templates:

• Grand total (tax + shipping included): Use $Order.Total.Nice in templates like SilverShop/Checkout/ReviewOrder.ss to display the final amount customers will pay.
• Subtotal (tax-inclusive, no shipping): Use $Order.SubtotalWithTax.Nice to show the sum of all products plus tax, before adding shipping costs.
• Per-item tax-inclusive prices: In the order items loop, use $Item.PriceWithTax.Nice to display each line item's inclusive price.

You don’t need to manually calculate these values—SilverShop handles modifier application and price aggregation automatically when the order is created. Just reference the appropriate methods in your templates to show the desired tax-inclusive prices.

内容的提问来源于stack exchange，提问作者seppzzz