Ok, I did a quick test, and it does look like the order line calculator could work.

What I've done is created a product node and added a price property as usual, but the I've also added another property with the alias priceBreaks which is a nested content instance made up of an element type with two properties

• Price The price for this price break using the Vendr price property editor
• Min Quantity A numeric input for the minimum number of items allowed for this price to apply.

I've then created an IOrderLineCalculator which you can find the code for on a gist here https://gist.github.com/mattbrailsford/518c5771de89a0fc35d0644ca126d229

using System;
using System.Collections.Generic;
using Umbraco.Core.Models.PublishedContent;
using Umbraco.Web;
using Vendr.Core.Calculators;
using Vendr.Core.Models;
using Vendr.Core.Services;
using Vendr.Web.Models;

namespace Vendr.DemoStore.Web.Calculators
{
    public class PriceBreakOrderLineCalculator : OrderLineCalculator
    {
        private readonly IStoreService _storeService;
        private readonly IProductPriceFreezerService _productPriceFreezerService;
        private readonly IUmbracoContextAccessor _umbracoContextAccessor;

        public PriceBreakOrderLineCalculator(ITaxService taxService, IStoreService storeService, IProductPriceFreezerService productPriceFreezerService,
            IUmbracoContextAccessor umbracoContextAccessor) 
            : base(taxService, storeService, productPriceFreezerService)
        {
            _storeService = storeService;
            _productPriceFreezerService = productPriceFreezerService;
            _umbracoContextAccessor = umbracoContextAccessor;
        }

        public override Price CalculateOrderLineUnitPrice(OrderReadOnly order, OrderLineReadOnly orderLine, Guid currencyId, TaxRate taxRate)
        {
            var store = _storeService.GetStore(order.StoreId);

            // See if the product node has a priceBreaks value
            // if not, return the default calculated unit price
            var node = _umbracoContextAccessor.UmbracoContext.Content.GetById(Guid.Parse(orderLine.ProductReference));
            if (!node.HasValue("priceBreaks"))
                return base.CalculateOrderLineUnitPrice(order, orderLine, currencyId, taxRate);

            // If we have price breaks, thaw any price we hold
            _productPriceFreezerService.ThawFrozenProductPrice(order.StoreId, order.Id, orderLine.ProductReference, currencyId);

            // Work out which price break applies
            var priceBreaks = node.Value<IEnumerable<IPublishedElement>>("priceBreaks");

            IPublishedElement targetPriceBreak = null;

            foreach (var priceBreak in priceBreaks)
            {
                var minQuantity = priceBreak.Value<int>("minQuantity");
                if (orderLine.Quantity >= minQuantity)
                {
                    targetPriceBreak = priceBreak;
                }
                else
                {
                    break;
                }
            }

            if (targetPriceBreak == null)
                throw new Exception("No valid price break found");

            // Get the price from the price break
            var prices = targetPriceBreak.Value<PricePropertyValue>("price");
            var price = prices.GetPriceFor(currencyId);

            // Return the price
            return Price.Calculate(price.Value, taxRate, currencyId, store.PricesIncludeTax);
        }
    }
}

This is then setup to replace the existing order line calculator by adding the following in a composer.

composition.RegisterUnique<IOrderLineCalculator, PriceBreakOrderLineCalculator>();

Now when you add a product to the order, when it exceeds a minimum quantity of a price break, the unit price becomes the new price.

There are a few elements missing here though. You'd need to handle displaying the price breaks on the product page in some way outside of Vendr. Likely you'll probably need to loop the nested content item, then retrieve the price for the current currency and format the value yourself. This is normally taken care of by Vendr, but as it only expects one price, it can't currently handle this.

Also, I've kinda disabled price freezing if price breaks apply. I need to think harder whether we can freeze the price here (I think we can, but I'll need to think harder).

Anywho. It's up to you which approach you take, but thought I'd try this out anyway to see if it is possible, which it is.

Matt

"the only way you could work that out is to create a dummy order, add the product in those quantities and then see what the price is after the discount"

using (var uow = _uowProvider.Create())
{
    var order = Order.Create(uow, store.Id, "it",
        (Guid)store.BaseCurrencyId,
        (Guid)store.DefaultTaxClassId,
        VendrApi.Instance.GetOrderStatus(store.Id, "new").Id)
        .AddProduct(content.Key.ToString(), null, 1);

    return order?.TransactionAmount?.Value;
}

I tried with this code, but I have strange behaviors, sometimes TransactionAmount is zero. Is it the right way to get the order amount with some automatic discounts applied? I need this information in the product detail page, so it is probably not that heavy.

You could try calling Recalculate before reading the transaction amount to ensure the calculation pipeline has run

Hi James

Cool. I’ll review it again tomorrow now I know you are going down that route and investigate the ramifications of the price freezing.

I think beyond that, everything else should be fine. Maybe the only other minor thing is a lack of any indication why the price is less, but I don’t think that’s a major problem.

Matt

Have you set your composer to compose after the Vendr one?

https://vendr.net/docs/core/1-2-0/key-concepts/dependency-injection/#registering-dependencies

Matt

I have now! Sorry, should have checked that. Sorted now. Thanks again, your solution seems to be working very nicely.

James

Brilliant Matt, thanks. I will give this version a go. Will report back if I encounter any issues.

James

Hey Matt,

is there a way to just disable freezing price at all?

If not how to best to handle thawing prices at checkout level when we have some discounts based on Member roles and we're using our custom ProductSnapshot to calculate it.

Can I just use ThawPrices() method in CalculateOrderLineUnitPrice() on OrderLineCalculator class?

Hi Łukasz,

Yes, you can use the ThawPrices() method to thaw all the prices for an order. Generally you'd probably want to do this within an event handler somewhere, but without knowing your full setup, I can sugget which ones.

Hope this helps

Matt

PS In future, would you mind starting your own support thread, rather than adding the question onto an already closed issue as it makes it harder for people to find answers if they are having similar problems.

I've created a new thread here https://our.umbraco.com/packages/website-utilities/vendr/vendr-support//104905-vendr-disable-freeze-pricing. If you could take a look and point me to the right direction.