Edition 0 Updated to asp. Net core 0

foreach
(
var
item 
in
message.
OrderItems
) 
{ 
order.
AddOrderItem
(item.
ProductId
, item.
ProductName
, item.
UnitPrice
, 
item.
Discount
, item.
PictureUrl
, item.
Units
); 
} 
_logger.
LogInformation
(
"----- Creating Order - Order: {@Order}"
, order); 
_orderRepository.
Add
(order); 
return
await _orderRepository.
UnitOfWork
.
SaveEntitiesAsync
(cancellationToken); 
} 
} 
These are additional steps a command handler should take: 
•
Use the command’s data to operate with the aggregate
root’s methods and behavior.
•
Internally within the domain objects, raise domain events while the transaction is executed, but 
that is transparent from a command handler point of view. 
•
If the aggregate’s operation result is successful and after the transac
tion is finished, raise 
integration events. (These might also be raised by infrastructure classes like repositories.) 

---

279 
CHAPTER 6 | Tackle Business Complexity in a Microservice with DDD and CQRS Patterns 
Additional resources 
•
Mark Seemann. At the Boundaries, Applications are Not Object-Oriented
https://blog.ploeh.dk/2011/05/31/AttheBoundaries,ApplicationsareNotObject-Oriented/
 
•
Commands and events
https://cqrs.nu/Faq/commands-and-events
 
•
What does a command handler do?
https://cqrs.nu/Faq/command-handlers
 
•
Jimmy Bogard. Domain Command Patterns 
–
 Handlers
https://jimmybogard.com/domain-command-patterns-handlers/
 
•