Each pricing engine calls a corresponding helper method in the Qualifier class to determine the objects to which it should apply a discount. The Qualifier determines whether anything qualifies for the discount and then figures out which pieces should receive the discount.
The Qualifier determines which things should change and how they should be discounted; it does not modify the actual prices. The pricing engine passes the parameters that make up its pricing context to the qualifier, and goes through the result set returned by the qualifier, calling the correct calculator to discount each element as appropriate.
ItemPricingEngineuses the qualifier’sfindQualifyingItemsmethod, which returns a Collection ofQualifiedItems. EachQualifiedItemmaps aDetailedItemPriceInfoto the list of Ranges that qualified for the discount. TheCommerceItemcontaining theseDetailedItemPriceInfosis also stored. For more information, see the QualifiedItem Class.OrderPricingEngineuses the qualifier’sfindQualifyingOrdermethod, which returns aMatchingObjectidentifying theOrderto discount.ShippingPricingEngineuses the qualifier’sfindQualifyingShippingmethod, which returns aMatchingObjectobject identifying theShippingGroupto discount.
Each method determines its result set by comparing the PMDL rule of a given promotion to the input item or items.
The doFilters() method evaluates items in the qualifier and target rules. It takes an array of filter components, which act to disqualify items from the qualifier or target; see the Qualifier Properties section for descriptions of the filters.
