Here you will find information on what sort of promotions we can do, and any set up information required to make the promotion work

We received some extra information about Promotion and how the work - this is what he said:

1. If a basket level promotion is applied, the promotion_id and promotion_message will be persisted to the resulting sales_order_group and all its child sales_order records.
   
   The discount amount applied to the basket as a result of this promotion is persisted to sales_order_group.promotional_discount and this is apportioned and persisted on each sales_order.promotional_discount.
   
   Also, the basket discount amount is apportioned to each order line and persisted to sales_order_line.apportioned_promotional_discount.
   
   
2. If a product level promotion is applied, the promotion_id and promotion_message is persisted the sales_order_line records it affects and the discount amount is persisted to sales_order_line.promotional_discount.
3. Only a single promotion can be applied at each level, e.g. you can have one basket level promotion and one line level promotion per order line, and they can both be applied on a single order. In that case you would have the basket level promotion ID persisted to the sales_order_group and each of the sales_order records, and the line level promotion ID would be persisted to those sales_order_line records that it applies to.

Promotion applicator - (VwFreeProductPromotionApplicator):

The PromotionApplicator is a way to leverage the complex rules-based promotion engine for product type promotions, without having to apply the rules manually.

Here is an overview of how product type promotions work:

Product type promotions are promotions where a reward is applied to the customer's basket based on the contents (the basket lines) of the basket.

The promotions can have both a trigger rule and a reward rule to select the basket lines that are involved in the promotion. The quantities of the selected basket lines are used to determine the number of times that the promotion can be applied.

If the triggered basket lines are also the ones rewarded (e.g. BOGOF) then the promotion does not require a separate reward expression. The promotion engine applies the rules and if applicable will pass the details to the promotion applicator where the reward can be applied. It does this by calling the 'apply' method of the applicator object, passing in the following details:

• Promotion: the promotion that is being triggered.
• Channel: the sales channel (Web, Subscription, Telesales)
• Basket: the customer's basket
• Trigger items: the list of basket lines that have matched the trigger expression 
• Reward items: the list of basket lines that have matched the reward expression (this could be the same list as the trigger items, if no reward expression is required)
• Number of applications: the number of times the promotion can be applied to the reward items.
• Reward quantity: the quantity of the reward items that is required per application

For example, a "buy one of product X, get one of product Y free" will only be triggered if the basket contains at least one X and one Y product in the basket. If the basket contains 2 of product X and 3 of product Y (say) then the promotion can be applied to the basket line twice. The result will be that the customer will only be charged for one product Y. In this example, a promotion applicator would be passed the following data:

• Promotion
• Channel
• Basket 
• The triggering basket lines: A list containing the basket line with 2 of product X
• The rewarded basket lines: A list containing the basket line with 3 of product Y
• The number of applications, which is 2.
• The reward quantity which is one (since it is get one of product Y free)

In this example it would be up to the PromotionApplicator to apply the discount ( 2 x the cost of Y) to the rewarded basket line.