Am not quite sure what you want to do, when you want to use the calculated value, but maybe something like this? This basically takes the lowest stock level for all variations in the package.

public decimal LowestStockForPackage(PackageContent packageContent)
        {
            IContentRepository repo = ServiceLocator.Current.GetInstance<IContentRepository>();
            InventoryLoader inventoryLoader = ServiceLocator.Current.GetInstance<InventoryLoader>();
            IEnumerable<ContentReference> packageEntryLinks = packageContent.GetEntries();

            List<decimal> stockList = new List<decimal>();

            foreach (ContentReference contentReference in packageEntryLinks)
            {
                VariationContent variant;

                if (repo.TryGet(contentReference, out variant))
                {
                    stockList.AddRange(variant.GetStockPlacement(inventoryLoader).Select(i => i.InStockQuantity));
                }
            }

            return stockList.Min();
        }

Probably you'd want to add the inventory to the packaga within Find?

Hello Jeroen,

Thank you for your input.

My task is to have Package Stock Level automatically recalculated in EpiServer Edit Mode.

Scenario: In case I am an editor and I am changing Stock Level of variations, I would like to see that Package Stock Level is also updated based on Variation Stock Level value.

So, I am looking for an approach to make this integration correctly from EpiServer perspective, like subscription on events, or overriding some classes.

Thank you,

Maria 

I think InventoryUpdated is your best choice. You can always get the content (which should be cached always) and check if it is a package before continue processing. 

You could use something like this to update the stock for all packages a variation belongs to, using the code mentioned earlier, in the event Quan mentioned.

public void AdjustStockForPackage(VariationContent variationContent)
        {
            IInventoryService inventoryService = ServiceLocator.Current.GetInstance<IInventoryService>();
            IContentLoader contentLoader = ServiceLocator.Current.GetInstance<IContentLoader>();
            IWarehouseRepository warehouseRepository = ServiceLocator.Current.GetInstance<IWarehouseRepository>();

            IEnumerable<ContentReference> references = variationContent.GetParentPackages();

            IEnumerable<PackageContent> items = contentLoader.GetItems(references, (CultureInfo)null).OfType<PackageContent>();

            IWarehouse firstWarehouse = warehouseRepository.GetDefaultWarehouse();

            foreach (PackageContent packageContent in items)
            {
                InventoryRecord inventoryRecord = inventoryService.Get(packageContent.Code, firstWarehouse.Code);

                if (inventoryRecord == null)
                {
                    continue;
                }

                decimal lowestStock = LowestStockForPackage(packageContent);

                inventoryRecord.PurchaseAvailableQuantity = lowestStock;

                inventoryService.Update(new[] { inventoryRecord });
            }
        }

Thank you all, I found kind of similar discussion in http://world.episerver.com/forum/developer-forum/Episerver-Commerce/Thread-Container/2016/4/set-inventory-and-variationrow-on-entryupdating/

I will try out this approach.

Thank you