Feature: #615 - Allow FeVariant to have a price

Description

The default FeVariant implementation cannot have a price. In order to be able to process own FeVariants with a price, the method arguments should use a FeVariantInterface instead.

The FeVariantWithPriceInterface extends the FeVariantInterface with a getPrice() method. The price calculation of a product then takes into account whether the FeVariant implements the FeVariantWithPriceInterface to add this price as well.

To create an own FeVariant for a Product, you have to replace the CreateCartFrontendVariants EventListener.

Extcode\CartProducts\EventListener\Create\CreateCartFrontendVariants: null

MyVendor\MyExtension\EventListener\Create\CreateCartFrontendVariants:
  tags:
    - name: event.listener
      identifier: 'cart-products--create--create-cart-frontend-variants'
      event: Extcode\CartProducts\Event\RetrieveProductsFromRequestEvent
      after: 'cart-products--create--load-product'

This is very flexible. You can implement FeVariants as checkboxes and add some surcharge for some options. Another idea is to calculate the price markup depending on the number of characters entered.How you can use this is up to you. However, you should test carefully whether the price calculation for the product price then fits, especially if you use more than one front-end variant with a price for a product.

Impact

No Impact.