Add delivery cost

A fixed delivery cost is implemented by default in the Litium Studio project which takes the delivery method cost as a constant delivery cost. If you need a different behaviour, like calculating the delivery cost based on an ERP system or your own logic, then it is required to implement calculating delivery cost.

The ideal scenario is to have a step-wise cost which changes based on following parameters.

1. Delivery provider: Distributor of goods, for example DHL, Posten, etc.
2. Delivery method: for example By Air, Express post, Home delivery, etc..
3. Amount of total articles weight
4. Shipment destination.

The ERP system or the delivery processing system will most probably do the above calculation, and for this example, we will simply assume a fake ERP system cost.

Adding a delivery cost from ERP

We get the delivery cost before from a ERP system, but note that the calculation of delivery vat percentage should be done according to the Swedish VAT rules. Swedish VAT rules specifies that delivery cost VAT should be proportional to the amount of VAT in the items bought. This rule can be different in other countries, and therefore you need to be careful when determining VAT for deliveries and whether your ERP system derrived price is with or without VAT.

1. Add a new visual studio class library project into your solution. (for this example we use the project Litium.Studio.Sample).
2. Create a class that extends DeliveryCostCalculator which is the default implementation of IDeliveryCostCalculator

using Litium.Foundation.Modules.ECommerce.Carriers;
using Litium.Foundation.Modules.ECommerce.Plugins.Deliveries;
using Litium.Foundation.Security;

namespace Litium.Studio.Sample.ECommerce.PricingRules
{
    /// <summary>
    /// Sample implementation of IDeliveryCostCalculator.
    /// </summary>
    public class SampleDeliveryCostCalculator : DeliveryCostCalculator
    {
        /// <summary>
        /// Calculate the delivery cost connected to a single delivery.
        /// </summary>
        /// <param name="orderCarrier">The order carrier.</param>
        /// <param name="deliveryCarrier">Carrier containing complete information about the delivery.
        /// Update the delivery cost and other information in delivery carrier.</param>
        /// <param name="token">Security token.</param>
        public override void CalculateFromCarrier(OrderCarrier orderCarrier, DeliveryCarrier deliveryCarrier, SecurityToken token)
        {
            //initialize costs to zero.
            deliveryCarrier.DeliveryCost = 0;
            deliveryCarrier.DeliveryCostWithVAT = 0;

            //send the orderCarrier and the deliveryCarrier which contains all necessary information about the order to the ERP system,
            //and obtain the delivery cost.
            var cost = 100; // var cost = CostFromERP(currency, deliveryItems, deliveryMethod);
            var includeVat = true; //set based on your ERP calculation.
            if (includeVat)
            {
                deliveryCarrier.DeliveryCostWithVAT = cost;
                deliveryCarrier.KeepDeliveryCostWithVatConstant = true;   
                //deliveryCarrier.DeliveryCost will be calculated by VAT plugin
            }
            else
            {
                deliveryCarrier.DeliveryCost = cost;
                deliveryCarrier.KeepDeliveryCostWithVatConstant = false;
                //deliveryCarrier.DeliveryCostWithVAT will be calculated by VAT plugin
            }
        }
    }
}

3. Copy the .dll which contain your class into webroot/bin folder. Litium Studio will detect and start using your code instead of the default implementation.

    

Note that, if you are using the default checkout flow plugin, when an end customer first start shopping in your site, there will be a default delivery created with the first delivery method available. So you will always be getting into this calcualtion because of it, even though you might have not explicitly added a delivery in your checkout flow pages yet.