Order form calculator

Total. Calculates the total for an order form.

public void GetTotal(IOrderForm orderForm, IMarket market, Currency currency, IOrderFormCalculator orderFormCalculator)
          {
            var total = orderFormCalculator.GetTotal(orderForm, market, currency);
            Debug.WriteLine("Total for order form '{0}': {1}", orderForm.OrderFormId, total);
          }

SubTotal. Calculates the total of all shipments in an order form.

public void GetSubTotal(IOrderForm orderForm, Currency currency, IOrderFormCalculator orderFormCalculator)
          {
            var subTotal = orderFormCalculator.GetSubTotal(orderForm, currency);
            Debug.WriteLine("Subtotal for order form '{0}': {1}", orderForm.OrderFormId, subTotal);
          }

HandlingTotal. Calculates the handling total for an order form.

public void GetHandlingTotal(IOrderForm orderForm, Currency currency, IOrderFormCalculator orderFormCalculator)
          {
            var handlingTotal = orderFormCalculator.GetHandlingTotal(orderForm, currency);
            Debug.WriteLine("Handling total for order form '{0}': {1}", orderForm.OrderFormId, handlingTotal);
          }

ShippingSubtotal. Calculates the shipping subtotal for an order form.

public void GetShippingSubTotal(IOrderForm orderForm, IMarket market, Currency currency, IOrderFormCalculator orderFormCalculator)
          {
            var shippingSubTotal = orderFormCalculator.GetShippingSubTotal(orderForm, market, currency);
            Debug.WriteLine("Shipping subtotal for order form '{0}': {1}", orderForm.OrderFormId, shippingSubTotal);
          }

OrderDiscountTotal. Calculates the order form discount amount. It is the total of all order-level discounts of all line items in all shipments in an order form.

public void GetOrderDiscountTotal(IOrderForm orderForm, Currency currency, IOrderFormCalculator orderFormCalculator)
          {
            var orderDiscountTotal = orderFormCalculator.GetOrderDiscountTotal(orderForm, currency);
            Debug.WriteLine("Order discount total for order form '{0}': {1}", orderForm.OrderFormId, orderDiscountTotal);
          }

DiscountTotal. Calculates the order form discount total. It is the total of
- order-level discount amounts
- line item discount amounts for all line items in all shipments
- shipment discount amounts of all shipments in an order form

public void GetDiscountTotal(IOrderForm orderForm, Currency currency, IOrderFormCalculator orderFormCalculator)
          {
            var discountTotal = orderFormCalculator.GetDiscountTotal(orderForm, currency);
            Debug.WriteLine("Discount total for order form '{0}': {1}", orderForm.OrderFormId, discountTotal);
          }

OrderFormTotals. Calculates the order form total.

public void GetOrderFormTotals(IOrderForm orderForm, IMarket market, Currency currency, IOrderFormCalculator orderFormCalculator)
          {
            var orderFormTotals = orderFormCalculator.GetOrderFormTotals(orderForm, market, currency);
        
            Debug.WriteLine("Handling total for order form '{0}': {1}", orderForm.OrderFormId, orderFormTotals.HandlingTotal);
            Debug.WriteLine("Shipping subtotal for order form '{0}': {1}", orderForm.OrderFormId, orderFormTotals.ShippingTotal);
            Debug.WriteLine("Tax total for order form '{0}': {1}", orderForm.OrderFormId, orderFormTotals.TaxTotal);
            Debug.WriteLine("Subtotal for order form '{0}': {1}", orderForm.OrderFormId, orderFormTotals.SubTotal);
            Debug.WriteLine("Discount total for order form '{0}': {1}", orderForm.OrderFormId, orderFormTotals.DiscountTotal);
            Debug.WriteLine("Total for order form '{0}': {1}", orderForm.OrderFormId, orderFormTotals.Total);
          }

TaxTotal. Calculates an order form's tax total.

public void GetTaxTotal(IOrderForm orderForm, IMarket market, Currency currency, IOrderFormCalculator orderFormCalculator)
          {
            var taxTotal = orderFormCalculator.GetTaxTotal(orderForm, market, currency);
            Debug.WriteLine("Tax total for order form '{0}': {1}", orderForm.OrderFormId, taxTotal);
          }

Changing the default calculation

By inheriting from the default implementation of the interface, DefaultOrderFormCalculator, you can override the calculations. Just override one or more methods in DefaultOrderFormCalculator.

public class OrderFormCalculatorOverridingDefault : DefaultOrderFormCalculator
          {
            public OrderFormCalculatorOverridingDefault(IShippingCalculator shippingCalculator, ITaxCalculator taxCalculator)
              : base(shippingCalculator, taxCalculator)
              { }
            protected override Money CalculateTotal(IOrderForm orderForm, IMarket market, Currency currency)
              {
                return new Money(0, currency);
              }
            protected override Money CalculateSubtotal(IOrderForm orderForm, Currency currency)
              {
                return new Money(0, currency);
              }
            protected override Money CalculateHandlingTotal(IOrderForm orderForm, Currency currency)
              {
                return new Money(0, currency);
              }
            protected override Money CalculateShippingSubTotal(IOrderForm orderForm, IMarket market, Currency currency)
              {
                return new Money(0, currency);
              }
            protected override Money CalculateTaxTotal(IOrderForm orderForm, IMarket market, Currency currency)
              {
                return new Money(0, currency);
              }
          }

Change the default validation

The default implementation validates that the total is not negative after the calculation. To change the behavior, override the appropriate method: ValidateTotal, ValidateSubtotal, ValidateHandlingTotal, ValidateShippingSubtotal, or ValidateTaxTotal.

public class OrderFormCalculatorOverridingDefault : DefaultOrderFormCalculator
      {
        public OrderFormCalculatorOverridingDefault(IShippingCalculator shippingCalculator, ITaxCalculator taxCalculator)
          : base(shippingCalculator, taxCalculator)
          { }
        protected override void ValidateTotal(Money money)
          {
            if (money.Amount <= 0)
              {
                throw new ValidationException("Order total must be greater than 0");
              }
          }
        protected override void ValidateSubtotal(Money money)
          {
            if (money.Amount <= 0)
              {
                throw new ValidationException("Subtotal must be greater than 0");
              }
          }
        protected override void ValidateHandlingTotal(Money money)
          {
            if (money.Amount <= 0)
              {
                throw new ValidationException("Handling total must be greater than 0");
              }
          }
        protected override void ValidateShippingSubTotal(Money money)
          {
            if (money.Amount <= 0)
              {
                throw new ValidationException("Shipping subtotal must be greater than 0");
              }
          }
        protected override void ValidateTaxTotal(Money money)
          {
            if (money.Amount <= 0)
              {
                throw new ValidationException("Tax total must be greater than 0");
              }
          }
      }