Edition 0 Updated to asp. Net core 0

public
class
CreateOrderCommandHandler 
: IRequestHandlerbool
> 
{ 
private
readonly
IOrderRepository _orderRepository; 
private
readonly
IIdentityService _identityService; 
private
readonly
IMediator _mediator; 
private
readonly
IOrderingIntegrationEventService _orderingIntegrationEventService; 
private
readonly
ILogger _logger; 
// Using DI to inject infrastructure persistence Repositories
public
CreateOrderCommandHandler
(IMediator mediator, 
IOrderingIntegrationEventService orderingIntegrationEventService, 
IOrderRepository orderRepository, 
IIdentityService identityService, 
ILogger logger) 
{ 
_orderRepository = orderRepository ?? 
throw
new
ArgumentNullException
(
nameof
(orderRepository)); 
_identityService = identityService ?? 
throw
new
ArgumentNullException
(
nameof
(identityService)); 
_mediator = mediator ?? 
throw
new
ArgumentNullException
(
nameof
(mediator)); 
_orderingIntegrationEventService = orderingIntegrationEventService ?? 
throw
new
ArgumentNullException
(
nameof
(orderingIntegrationEventService)); 
_logger = logger ?? 
throw
new
ArgumentNullException
(
nameof
(logger)); 

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287 
CHAPTER 6 | Tackle Business Complexity in a Microservice with DDD and CQRS Patterns 
} 
public
async Task<
bool
> 
Handle
(CreateOrderCommand message, CancellationToken 
cancellationToken) 
{ 
// Add Integration event to clean the basket
var
orderStartedIntegrationEvent = 
new
OrderStartedIntegrationEvent
(message.
UserId
); 
await 
_orderingIntegrationEventService.
AddAndSaveEventAsync
(orderStartedIntegrationEvent); 
// Add/Update the Buyer AggregateRoot
// DDD patterns comment: Add child entities and value-objects through the Order 
Aggregate-Root
// methods and constructor so validations, invariants and business logic
// make sure that consistency is preserved across the whole aggregate
var
address = 
new
Address
(message.
Street
, message.
City
, message.
State
, 
message.
Country
, message.
ZipCode
); 
var
order = 
new
Order
(message.
UserId
, message.
UserName
, address, 
message.
CardTypeId
, message.
CardNumber
, message.
CardSecurityNumber
, message.
CardHolderName
, 
message.
CardExpiration
);