Changing pricing rules

Pricing rules are applied when calculating the order grand total. The main areas of price calculations in an order are:

• calculating order totals
• calculating VAT
• fees
• delivery costs.

All these calculations are made in the pricing rules plugin, which consists of four sections.

1. Calculating order totals is implemented in the OrderTotalCalculator class, which implements the IOrderTotalCalculator interface.
2. Calculating VAT is implemented in the VatCalculator class, which implements the IVatCalculator interface.
3. Calculating fees is implemented in the FeesCalculator class, which implments the IFeesCalculator interface.
4. Calculating delivery costs is implmented in the DeliveryCostCalculator class, which implements the IDeliveryCostCalculator interface.

Each of above four implementations can be replaced by custom code.

To replace the default implementation, make your own class and implement the intended interface from the list above, or extend the default implementation (inherit the class from the default implementation class) and copy the .dll that contains your class into the webroot/bin folder.

For example, to introduce your own fees, you would write your own class, which extends the FeeCalculator default implementation of the IFeeCalculator interface. If the class name is BasicFeeCalculator, and it is contained in the assembly Litium.Studio.Sample, the corresponding implementation class BasicFeeCalculator would look like this:

namespace Litium.Studio.Sample.ECommerce.PricingRules
{
    /// <summary>
    /// a basic fee calculator.
    /// </summary>
    public class BasicFeeCalculator : FeesCalculator
    {
        /// <summary>
        /// Calculate Fees.
        /// </summary>
        /// <param name="orderCarrier">Carrier for which fees need to be calculted</param>
        /// <param name="token">Security token.</param>
        public override void CalculateFromCarrier(OrderCarrier orderCarrier, SecurityToken token)
        {
            //TODO: implement fee calculation.
        }       
    }
}

When you have placed the .dll file into the bin directory, Litium will detect and start using the BasicFeeCalculator code instead of the default implementation.