Displaying Catalogue Discount Prices

Saleor API provides pricing information that can be consumed by your storefront for four different scenarios:

• Individual ProductVariant pricing, which provides prices of a specific SKU (VariantPricingInfo)
• Aggregated Product pricing, which provides a range of ProductVariant prices (ProductPricingInfo)
• Pricing information included in CheckoutLine for products that are added to the cart/checkout
• OrderLine pricing information concerning products that were purchased by the customer

Types of Promotional Prices

There are three main types of promotional prices that you can use to display prices in a storefront:

• price - includes relevant discounts (depending on context)
• priceUndiscounted - price before any discounts are applied
• pricePrior - price in the period before the promotion. This price is not tracked automatically by Saleor (see section below)

On top of that, Saleor provides discount calculations relative to priceUndiscounted and pricePrior for Product and ProductVariant.

Using pricePrior as a Base for Discount Calculations

For some geographies, it might be required to calculate discounts based on the lowest price before the promotion. An example of such a requirement is the EU Omnibus directive. Given that there are many different interpretations of the “lowest price”, Saleor does not track pricePrior automatically. However, it can be provided using productVariantChannelListingUpdate or productVariantBulkUpdate mutations.

After providing pricePrior to ProductVariantChannelListing, it will be propagated to pricing information for Product, ProductVariant, and CheckoutLine as mentioned above.

Example Workflow Using a Custom Saleor App

To implement the EU Omnibus directive, you can use a custom Saleor Application that:

• Tracks changes in ProductVariant prices using webhooks (PRODUCT_VARIANT_UPDATED) or/and queries and records them in a database
• Monitors when a promotion starts using webhooks (PROMOTION_STARTED) and obtains a list of relevant ProductVariants from the catalog predicate
• Calculates the price prior to the promotion (taking into account custom requirements) and updates pricePrior using productVariantChannelListingUpdate or productVariantBulkUpdate mutations.