public async Task <SubmitNewPaidTimeOffRequestViewModel> Handle(SubmitNewPaidTimeOffRequestCommand request, CancellationToken cancellationToken)
{
var today = DateTime.Today;
// PRESENTATION/APPLICATION LAYER
var timeOffRequestViewModel = request.PaidTimeOffRequest;
timeOffRequestViewModel.StartDate = timeOffRequestViewModel.StartDate.Date;
timeOffRequestViewModel.EndDate = timeOffRequestViewModel.EndDate.Date;
// PERSISTENCE LAYER
var submittedByEntity = await facade.QueryFirstOrDefaultAsync <EmployeeEntity>(@"SELECT TOP 1 * FROM Employees WITH(NOLOCK) WHERE AspNetUsersId = @AspNetUsersId AND TenantId = @TenantId", new { request.AspNetUsersId, request.PaidTimeOffRequest.TenantId });
var forEmployeeEntity =
timeOffRequestViewModel.ForEmployeeId == null?
context.Employees.Include(e => e.PaidTimeOffPolicy).Include(e => e.ForPaidTimeOffRequests).FirstOrDefault(e => e.AspNetUsersId == request.AspNetUsersId && e.TenantId == request.PaidTimeOffRequest.TenantId) :
context.Employees.Include(e => e.PaidTimeOffPolicy).Include(e => e.ForPaidTimeOffRequests).FirstOrDefault(e => e.Id == timeOffRequestViewModel.ForEmployeeId && e.TenantId == request.PaidTimeOffRequest.TenantId)
;
// TODO: if submitting on behalf of another employee, use the domain layer to validate that they have the privileges to do so.
if (
forEmployeeEntity == null ||
submittedByEntity == null)
{
throw new ApplicationLayerException(@"Unable to query employees while trying to create time off request aggregate.");
}
// DOMAIN LAYER
var forEmployee = mapper.MapDbEntityToDomainEntity <EmployeeEntity, Employee>(forEmployeeEntity);
var submittedByEmployee = mapper.MapDbEntityToDomainEntity <EmployeeEntity, Employee>(submittedByEntity);
var paidTimeOffPolicy = mapper.MapDbEntityToDomainEntity <PaidTimeOffPolicyEntity, PaidTimeOffPolicy>(forEmployeeEntity.PaidTimeOffPolicy);
var existingRequests = (from req in forEmployeeEntity.ForPaidTimeOffRequests select mapper.MapDbEntityToDomainEntity <PaidTimeOffRequestEntity, PaidTimeOffRequest>(req)).ToList();
// Build up the Domain aggregate entity so that complex business logic can be executed against it. In an enterprise (non-demo) solution this
// would likely involve special rules involving accrued hours, whether the company allows going negative in PTO hours, managerial overrides,
// etc. The point is that the entities, and the logic which operates against them, are separate from view models and database persistence models.
var submittedRequest =
mapper.MapViewModelToDomainEntity <SubmitNewPaidTimeOffRequestViewModel, PaidTimeOffRequest>(request.PaidTimeOffRequest)
.WithForEmployee(forEmployee)
.WithSubmittedBy(submittedByEmployee)
.WithPaidTimeOffPolicy(paidTimeOffPolicy);
// Ensure the aggregate is in a valid state with which to perform business logic.
submittedRequest.ValidateAggregate();
// Perform basic validation against the request to make sure that the employee is OK to submit this paid time off request. Once again, the logic
// inside the service is naive and overly-simplistic. A real-life solution would be much more involved.
var validationResult = paidTimeOffRequestService.ValidatePaidTimeOffRequest(submittedRequest, existingRequests, paidTimeOffPolicy, today);
timeOffRequestViewModel.Result = validationResult;
if (validationResult != PaidTimeOffRequestValidationResult.OK)
{
return(timeOffRequestViewModel);
}
// Submit the time off request (changes Domain state and creates event).
submittedRequest = submittedRequest.Submit();
// PERSISTENCE LAYER
var paidTimeOffRequestEntity = mapper.MapDomainEntityToDbEntity <PaidTimeOffRequest, PaidTimeOffRequestEntity>(submittedRequest);
paidTimeOffRequestEntity.TenantId = timeOffRequestViewModel.TenantId;
await context.PaidTimeOffRequests.AddAsync(paidTimeOffRequestEntity, cancellationToken);
await context.SaveChangesAsync(cancellationToken);
// PRESENTATION LAYER
request.PaidTimeOffRequest.CreatedPaidTimeOffRequest = mapper.MapDomainEntityToViewModel <PaidTimeOffRequest, PaidTimeOffRequestViewModel>(submittedRequest);
// DISPATCH DOMAIN EVENTS
await submittedRequest.DispatchDomainEventsAsync();
return(request.PaidTimeOffRequest);
}