Displaying Catalogue Discount Prices
Saleor API provides pricing information that can be consumed by your storefront for four different scenarios:
- Individual
ProductVariantpricing, which provides prices of a specific SKU (VariantPricingInfo) - Aggregated
Productpricing, which provides a range ofProductVariantprices (ProductPricingInfo) - Pricing information included in
CheckoutLinefor products that are added to the cart/checkout OrderLinepricing information concerning products that were purchased by the customer
Only catalogue promotions will result in changes to Product/Variant pricing. Order discounts and vouchers are applied only after the product is added to the Checkout.
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 appliedpricePrior- 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​
pricePrior is available starting from Saleor 3.21.
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
ProductVariantprices 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 relevantProductVariantsfrom the catalog predicate - Calculates the price prior to the promotion (taking into account custom requirements) and updates
pricePriorusingproductVariantChannelListingUpdateorproductVariantBulkUpdatemutations.