I need to store a price on Merchello but show another price calculated on the fly (it depends of if is customer, discounts...) Whats the best method?

I have made an extension method on ProductDisplay that i have to call before showing the product and when adding it to basket:

public static class ProductDisplayExtensions
    {
        public static void CheckPrices(this ProductDisplay model)
        {
            decimal precio = model.Price;
            //Normal user
            precio = precio * (decimal)1.25;
            //Registered
            var customerContext = new CustomerContext(UmbracoContext.Current);
            if (!customerContext.CurrentCustomer.IsAnonymous)
            {
                model.OnSale = true;
                model.SalePrice = model.Price * (decimal)1.20;
            }
            model.Price = precio;
            return;
        }
    }

This works ok but when preparing the invoice it shows the original price. What is the best method?

@Rusty i have added this class:

namespace Merchello.iCreativos.DataModifiers.Product
{
    using Merchello.Web.DataModifiers.Product;
    using System;
    using System.Runtime.InteropServices;

    using Merchello.Core;
    using Merchello.Core.Models;
    using Umbraco.Web;
    using Merchello.Web;


    using Umbraco.Core;

    /// <summary>
    /// The include tax in product price data modifier task.
    /// </summary>
    public class ProductPriceDataModifierTask : ProductVariantDataModifierTaskBase
    {
        /// <summary>
        /// Initializes a new instance of the <see cref="IncludeTaxInProductPriceDataModifierTask"/> class.
        /// </summary>
        /// <param name="merchelloContext">
        /// The merchello context.
        /// </param>
        public ProductPriceDataModifierTask(IMerchelloContext merchelloContext)
            : base(merchelloContext)
        {
        }

        /// <summary>
        /// Attempts to modify the product pricing with tax.
        /// </summary>
        /// <param name="value">
        /// The value.
        /// </param>
        /// <returns>
        /// The <see cref="Attempt"/>.
        /// </returns>
        public override Attempt<IProductVariantDataModifierData> PerformTask(IProductVariantDataModifierData value)
        {
            decimal precio = value.Price;
            //Margen
            precio = precio * (decimal)1.25;
            //Compruebo si hay que hacerle descuento
            var customerContext = new CustomerContext(UmbracoContext.Current);
            if (!customerContext.CurrentCustomer.IsAnonymous)
            {
                //Si es taller
                value.OnSale = true;
                value.SalePrice = value.Price * (decimal)1.20;
            }
            value.Price = precio;
            //var taxationContent = MerchelloContext.Gateways.Taxation;
            //if (!taxationContent.ProductPricingEnabled || !value.Taxable) return Attempt<IProductVariantDataModifierData>.Succeed(value);

            //var result = taxationContent.CalculateTaxesForProduct(value);
            //value.AlterProduct(result);
            return Attempt<IProductVariantDataModifierData>.Succeed(value);
        }
    }
}

Note that i can not use value.AlterProduct because it is protected.

And in merchello.config:

<taskChain alias="MerchelloHelperProductDataModifiers">
        <tasks>
            <task type="Merchello.Web.DataModifiers.Product.IncludeTaxInProductPriceDataModifierTask, Merchello.Web" />
            <task type="Merchello.iCreativos.DataModifiers.Product.ProductPriceDataModifierTask, Merchello.Web" />
        </tasks>
      </taskChain>

The thing is that my method is not called (i have a breakpoint on that) and the price is not showed on the product page. If i delete the task in merchello.config everything is fine. Why is not showing the price if my code is not called?

Even when only one line of code:

public override Attempt<IProductVariantDataModifierData> PerformTask(IProductVariantDataModifierData value)
        {
            return Attempt<IProductVariantDataModifierData>.Succeed(value);
        }

It is not executing and price is not showing. Im guessing is launching some error im not getting...

Definitely it is something related to this line:

<task type="Merchello.iCreativos.DataModifiers.Product.ProductPriceDataModifierTask, Merchello.Web" />

Merchello is failing to add this task, and that is the reason the price is not showing.

@Tito

Unless you recompiled Merchello, your task would not be in the Merchello.Web.dll.

You need to reference your project dll ...

 <task type="Merchello.iCreativos.DataModifiers.Product.ProductPriceDataModifierTask, [YOUR PROJECT]" />

Also, the data modifiers are executed in two places.

1) The MerchellHelper

 // This will execute the data modifier chain
 var merchello = new MerchelloHelper();

 // This will NOT execute the data modifier chain
 var merchello = new MerchelloHelper(false);

2) The CustomerItemCacheBase which the basket and sales preparation uses.

Checkout the comments in the Bazaar controller here:

https://github.com/Merchello/Merchello/blob/merchello-dev/src/Merchello.Bazaar/Controllers/BazaarBasketController.cs#L93

It is important to be aware when you are executing the chain or your values could be modified more than once.

My code was in Merchello.iCreativos namespace, in my App_Code. Does it need to be inside Merchello.Web? Do i need to change Merchello base code? I would not like to do so, because of reusing.

Im going to detail what i need to achieve in order for a better implementation. When importing all products into merchello, they all have a base price. (The price stored in Merchello). When showing / buying a product/variant i have to modify the product price due to this restrictions:

• All users have a price= base price*1.25
• Registered users marked as profesionals have a price = base price * 1.20.
• This factors (1.25 or 120) will depend of the main category of the product.
• In a future this could be used to manage discounts (as a discount by category or other umbraco related content)

So i guess it need to be recalculated each time the user logs in/out because it depends on current user. I think the taxesmodifier task will need to be ran after this pricemodifier task.

@Rusty you said there are different ways of do this, i would like to know them to choose the better. For future versions, it would be good to do this as Umbraco events, like having a PreProductBuilder for once the price and sale attributes are added to productdisplay you could modifie them and afterwards apply the taxes modifier. So doing this, would apply to the basket and invoice creation.

Thanks Rusty, now it works:

<task type="Merchello.iCreativos.DataModifiers.Product.ProductPriceDataModifierTask, App_Code" />

@Rusty i would like to access the Umbraco content Id asociated to the product inside the modifier. This is because my price modifier factor depends on data related to the product (ie. categories). I could do this getting the sku of the product, but i guess i cant not get it from IProductVariantDataModifierData object passed to the PerformTask method. Is there some way?

If there is no way of getting product sku or access the productdisplay from the modifier, i have seen in another post there is an "AddItem" method in the Basket that accepts the "price".

So i can use it like this:

//Here i use this extension method to modify de Price and SalePrice depending on brand, category, etc
product.CheckPrices();
var updatedPrice = product.OnSale ? product.SalePrice : product.Price;
this.Basket.AddItem(product.Name, product.Sku,  model.Quantity, updatedPrice, extendedData);

This seem to work as i can see on the basket page. But on the checkout i get a null shipment from the PackageBasket method, why?

var shipment = Basket.PackageBasket(shippingAddress).FirstOrDefault();

By the way, this is the post where i have seen this method in use:

https://our.umbraco.org/projects/collaboration/merchello/merchello//69645-tiered-pricing

In that post, he adds this to the extended data (may be this is the reason of the error):

var masterVariant = product.GetProductVariantForPurchase();
extendedData.AddProductVariantValues(masterVariant);

But i cant find "GetProductVariantForPurchase" method anymore. Whats the purpose of adding masterVariant to the extendedData collection?

I have managed to get the masterVariant, the code is like this:

var masterVariant = merchello.Query.Product.GetProductVariantBySku(product.Sku);
masterVariant.CheckPrices();
extendedData.AddProductVariantValues(masterVariant);
//var masterVariant = product.GetProductVariantForPurchase();
//extendedData.AddProductVariantValues(masterVariant);

var updatedPrice = masterVariant.OnSale ? masterVariant.SalePrice : masterVariant.Price;
this.Basket.AddItem(product.Name, product.Sku,  model.Quantity, updatedPrice, extendedData);

Now i can get the shipment, but as soon as i call "PackageBasket" method all my prices get overrided :(

Thanks @Rusty, but that didnt work...

I think the problem is not in the "PackageBasket". It is in the line:

viewModel.SaleSummary = _salePreparationSummaryFactory.Value.Build(basket.SalePreparation());

of the CreateCheckout method of the ViewModelFactory class of Bazaar.

As i see this basket.SalePreparation() is an extension method. It actually calls:

BasketSalePreparation.GetBasketCheckoutPreparation(merchelloContext, basket);

I think it is there where it overrides the price set in the Basket with the AddItem method.

Please, i need help with this as i believe it is the only thing its needed to complete my customer requirements and launch the site

Hmm - Another thought is it may be the validation that is catching the price.

Try setting the merchLineItemAllowsValidation to false in the extended data for the line item or removing the validation task altogether from the merchello.config ....

          <tasks>
        <task type="Merchello.Web.Validation.Tasks.ValidateProductsExistTask, Merchello.Web" />
        <!--
            The following task is intended to assert that pricing and/or on sale value has not changed in the back office since the
            customer has placed an item into their basket or wish list. If you have made custom pricing modifications in your
            implementation, you may either remove this task or adjust your code to add a new extended data value
            merchLineItemAllowsValidation = false
            to the line item so that it is skipped in the validation process.
        -->
        <task type="Merchello.Web.Validation.Tasks.ValidateProductPriceTask, Merchello.Web" />
        <!--
            Validates that products are still in inventory
        -->
        <task type="Merchello.Web.Validation.Tasks.ValidateProductInventoryTask, Merchello.Web" />
    </tasks>

You test before doing any additional code by removing the

  <task type="Merchello.Web.Validation.Tasks.ValidateProductPriceTask, Merchello.Web" />

line.

Thanks @Rusty, commenting that line in the merchello.config now it works!

I dont understand why i have to add this data to the extendeddata on basket controller. Could you tell me the purpose of this?

And i dont know if it is well done, as i have copied the code from another (old version) post. This is my final code:

    if (model.OptionChoices != null && model.OptionChoices.Any())
                {
                    // NEW in 1.9.1
                    // ProductDisplay and ProductVariantDisplay classes can be added directly to the Basket
                    // so you don't have to query the service.
                    var variant = product.GetProductVariantDisplayWithAttributes(model.OptionChoices);

//Here i change the prices
                    variant.CheckPrices();

                    //https://our.umbraco.org/projects/collaboration/merchello/merchello//69645-tiered-pricing
                    extendedData.AddProductVariantValues(variant);
                    List<string> attributes = variant.Attributes.Select(x => x.Name).ToList();
                    extendedData.SetValue("productAttributes", JsonConvert.SerializeObject(attributes));

                    var updatedPrice = variant.OnSale ? variant.SalePrice : variant.Price;
                    this.Basket.AddItem(variant.Name, variant.Sku, model.Cantidad, updatedPrice, extendedData);
                    //this.Basket.AddItem(variant, variant.Name,  model.Cantidad, extendedData);
                }
                else
                {
                    //https://our.umbraco.org/projects/collaboration/merchello/merchello//69645-tiered-pricing
                    var masterVariant = merchello.Query.Product.GetProductVariantBySku(product.Sku);

//Here i change the prices
                    masterVariant.CheckPrices();

                    extendedData.AddProductVariantValues(masterVariant);
                    //var masterVariant = product.GetProductVariantForPurchase();
                    //extendedData.AddProductVariantValues(masterVariant);

                    var updatedPrice = masterVariant.OnSale ? masterVariant.SalePrice : masterVariant.Price;
                    this.Basket.AddItem(product.Name, product.Sku,  model.Cantidad, updatedPrice, extendedData);
                    //this.Basket.AddItem(product, product.Name, model.Cantidad, extendedData);
                }

Hey Tito,

If you remove the validation line there is no need to add the additional key to your extended data collection. The key itself is used by the validation process to determine if the line item should be considered for validation - so it's sort of an either or.

The validation is there to protect the site from say a customer adding a product that is on sale to a saved basket or wishlist and then returning a week later when the item is no longer on sale. At that point, the prices are adjusted to the price in the back office so that the store does not sell something on sale when the sale is over.

OK i understand. Disabling the validation, i can add the item the old way. Here is my code now:

if (model.OptionChoices != null && model.OptionChoices.Any())
            {
                var variant = product.GetProductVariantDisplayWithAttributes(model.OptionChoices);
                variant.CheckPrecios();
                this.Basket.AddItem(variant, variant.Name,  model.Cantidad, extendedData);
            }
            else
            {
                product.CheckPrecios();
                this.Basket.AddItem(product, product.Name, model.Cantidad, extendedData);
            }

What i dont understand is that i updated the prices in the mastervariant that i added to the extendeddata. Why validation got the old prices? dont validation look for the values on the extendeddata for checking? I dont like disabling validation, may be i could write my own validation?

Hey Tito, I would have to step through it to see exactly where things are getting caught up, but writing your own validation is going to be pretty easy.

Validation is another task based chain, so you can write as many tasks as you need (or remove as you've seen) via the Merchello.config file.

Here is the product pricing task for reference.

https://github.com/Merchello/Merchello/blob/merchello-dev/src/Merchello.Web/Validation/Tasks/ValidateProductPriceTask.cs

Happy New Year!

Hi @Rusty,

I have added my custom validation class and added to the task chain. After a while, i have seen that the validator is the same, what i need to change is the ProductPricingValidationVisitor class. The code changed is as follows:

public void Visit(ILineItem lineItem)
        {
            if (lineItem.LineItemType != LineItemType.Product || !lineItem.AllowsValidation()) return;

            if (!lineItem.ExtendedData.DefinesProductVariant()) return;

            var item = _merchello.Query.Product.GetProductVariantByKey(lineItem.ExtendedData.GetProductVariantKey());

            //Here i change the prices to the variant
            item.CheckPrices();

            if (item.OnSale != lineItem.ExtendedData.GetOnSaleValue())
            {
                _invalidPrices.Add(lineItem, item);
                return;
            }

            if ((item.OnSale && (item.SalePrice != lineItem.Price)) || (!item.OnSale && (item.Price != lineItem.Price)))
            {
                _invalidPrices.Add(lineItem, item);
                return;
            }

            // Check if there have been any changes to the product through the service
            if (lineItem.ExtendedData.GetVersionKey() == item.VersionKey) return;

            // on sale
            if (item.OnSale != lineItem.ExtendedData.GetOnSaleValue())
            {
                _invalidPrices.Add(lineItem, item);
            }
        }

@Tito,

I would just write my own visitor and use it in your validation task. If your not familiar with the Visitor pattern, there is a good walk through on PluralSite

Thanks @Rusty, thats what i did and works OK. I created my own ValidateProductPriceTask and ProductPricingValidationVisitor classes. My ValidateProductPriceTask class is equal to the Merchello one but it calls my ProductPricingValidationVisitor custom class. This ProductPricingValidationVisitor only has one modification (as showed on upper code), it calls my "changing prices method" before checking changes.

Did anyone answer Tito's original query?

He mentioned he wanted to generate discounts

By category/collection or some content related on Umbraco By provider By product By variant

The idea being, if you have 100 t shirts, you don't want to have to tick them all individually to include them in the offer.

Is there a way of selecting an entire category/subcategory of products and have the offer apply to them all?

Thanks Rusty! I have added this via the issue tracker as you suggested.

I agree, I think it would be very useful functionality.

All the best

Shaun

Good day,

I successfully implemented my own ProductVariantDataModifierTaskBase class to handle customer based prices.

I notice that the PerformTask is reached once for each product, I assume that the values are being cached, because the PerformTask function is not called any more, only when I restart application or save some products. In that way other users getting the same prices displayed. This is not the desired situation.

Is there some way to disable the cache for the datamodifiers?

Many tanks in advance.

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