Stock items

On-hand inventory is tracked using the Spree::StockItem model. A stock item tracks stock at a single Spree::StockLocation.

If you only track stock at one stock location, then every Spree::Variant in your store has one corresponding Spree::StockItem object. If you track stock at two stock locations, then every Spree::Variant in your store has two corresponding Spree::StockItems: one for each Spree::StockLocation.

The Spree::StockItem's count_on_hand value that represents the number of items you have in stock.

Spree::StockItem objects have the following attributes:

• stock_location_id: The ID for the Spree::StockLocation where the stock item is located.
• variant_id: The ID for the Spree::Variant that this stock item represents.
• count_on_hand: The number of units currently in inventory. See Count on hand for more information.
• backorderable: Sets whether the stock item should be backorderable .
• deleted_at: A timestamp that logs when this stock item was deleted from inventory. Otherwise, the value is nil.

Count on hand

Administrators can manage the "Count On Hand" value for every product they sell on their store.

The count_on_hand value changes whenever a stock movement occurs. For example, if one unit of a product is sold the count_on_hand would decrease by one.

Changing the count on hand value

While a Spree::StockMovement object logs the increase or decrease of the count_on_hand value, administrators can also edit the count on hand from the solidus_backend.

Whenever an administrator updates the count on hand, they are discarding the old value completely. So, if a stock item's count_on_hand is 5, when the administrator changes the value to 20, they are creating a Spree::StockMovement with a value of 15.

See the Stock movements article for more information.

Backorderable stock items

If a Spree::StockItem is backorderable, then customers can continue to order it after the product is sold out. When a sold out product continues to sell, the count_on_hand becomes a negative integer.

For example, if a customer orders five backorderable items and its count_on_hand becomes -5, the customer can still check out successfully. Inventory units with the state value of backordered are created for the five items.

The Spree::Shipment(s) associated with the backordered items cannot be shipped until the stock has been replenished. Once the item is in stock again, each backordered inventory unit's state value is changed from backordered to on_hand and the shipment becomes shippable.