/// <summary>
/// Return the customer with the given CustomerId, or null if not found
/// </summary>
public RopResult <Customer, DomainMessage> GetById(CustomerId id)
{
var db = new DbContext();
// Note that this code does not trap exceptions coming from the database. What would it do with them?
// Compare with the F# version, where errors are returned along with the Customer
var result = db.Customers().Where(c => c.Id == id.Value).Select(FromDbCustomer).FirstOrDefault();
if (result == null)
{
return(Rop.Fail <Customer, DomainMessage>(DomainMessage.CustomerNotFound()));
}
return(result);
}
/// <summary>
/// Convert a DbCustomer into a domain Customer
/// </summary>
public static RopResult <Customer, DomainMessage> FromDbCustomer(DbCustomer sqlCustomer)
{
if (sqlCustomer == null)
{
return(Rop.Fail <Customer, DomainMessage>(DomainMessage.CustomerNotFound()));
}
var firstName = DomainUtilities.CreateFirstName(sqlCustomer.FirstName);
var lastName = DomainUtilities.CreateLastName(sqlCustomer.LastName);
var createName = Rop.Lift2 <String10, String10, PersonalName, DomainMessage>(PersonalName.Create);
var name = createName(firstName, lastName);
var id = DomainUtilities.CreateCustomerId(sqlCustomer.Id);
var email = DomainUtilities.CreateEmail(sqlCustomer.Email);
var createCust = Rop.Lift3 <CustomerId, PersonalName, EmailAddress, Customer, DomainMessage>(Customer.Create);
var cust = createCust(id, name, email);
return(cust);
}