Mapping complex DTOs to entities with automapper

Question

I want to map from

LDTTicketUploadDTO[] to IEnumerable<LDTTicket>

The mappings are created in this method and at the end I map the data.

public void UploadLDTTickets(LDTTicketUploadDTO[] ticketDTOs)
        {
            Mapper.CreateMap<LDTTicketUploadDTO, LDTTicket>();
            Mapper.CreateMap<LDTTicketDTO, LDTTicket>();
            Mapper.CreateMap<LDTCustomerDTO, LDTCustomer>();
            Mapper.CreateMap<LDTDeviceDTO, LDTDevice>();
            Mapper.CreateMap<LDTUnitDTO, LDTUnit>();
            Mapper.CreateMap<LDTCommandDTO, LDTCommand>();
            Mapper.CreateMap<LDTCommandParameterDTO, LDTCommandParameter>();
            Mapper.CreateMap<LDTObjectDTO, LDTObject>();
            Mapper.CreateMap<LDTControlFileDTO, LDTControlFile>();
            Mapper.CreateMap<LDTDeviceDTO, LDTDevice>();
            Mapper.CreateMap<LDTLanguageDTO, LDTLanguage>();
            Mapper.CreateMap<LDTObjectBitDTO, LDTObjectBit>();

            var tickets = Mapper.Map<IEnumerable<LDTTicketUploadDTO>, IEnumerable<LDTTicket>>(ticketDTOs);

           // do something with tickets
        }

This is how the DTO´s are structured:

 public class LDTTicketUploadDTO
     {
            public LDTTicketDTO Ticket { get; set; }
            public LDTDeviceDTO Device { get; set; }
            public LDTCustomerDTO Customer { get; set; }
     }



 public enum TicketStatus
    {
        New,
        InProgress,
        Done
    }    

    public class LDTTicketDTO
    {
        public bool UploadNeeded { get; set; }
        public string TicketNumber { get; set; }
        public TicketStatus Status { get; set; }
        public string CreatedBy { get; set; }
        public DateTime CreatedOn { get; set; }
        public string AssignedTo { get; set; }
        public IEnumerable<LDTUnitDTO> Units { get; set; }
    }

 public class LDTUnitDTO
    {
        public int Id { get; set; }
        public string FunctionUnit { get; set; }
        public int FunctionUnitAddress { get; set; }
        public string Zone { get; set; }
        public int ZoneUnitAddress { get; set; }
        public string Object { get; set; }
        public int ObjectAddress { get; set; }
        public IEnumerable<LDTCommandDTO> Commands { get; set; }
    }

and more...

What works is that these properties are correctly mapped to their counterpart entities:

public LDTDeviceDTO Device { get; set; }
public LDTCustomerDTO Customer { get; set; }

What works NOT is that this property is not mapped:

  public LDTTicketDTO Ticket { get; set; }

This is how the Entities are structured:

public class LDTTicket
    {
        [Key, Column(Order = 0)]
        [Required]
        public string SerialNumber { get; set; }

        [Key, Column(Order = 1)]
        [Required]
        public string TicketNumber { get; set; }

        [Required]
        public DateTime CreatedOn { get; set; }

        [Required]
        public string AssignedTo { get; set; }

        public TicketStatus Status { get; set; }
        public string CreatedBy { get; set; }
        public bool UploadNeeded { get; set; }

        public virtual LDTCustomer Customer { get; set; }
        public virtual LDTDevice Device { get; set; }
        public virtual ICollection<LDTUnit> Units { get; set; }
    }

ONLY the Customer and Device property are mapped in the LDTTicket

What is wrong with my configuration?

Answer 1

It's expecting to populate a LDTTicket sub-property on the ticket, not the matching properties of the ticket itself. Create direct mappings onto the ticket from the Ticket subproperty of the source directly onto the matching properties of the destination. NOTE: You only need to define your mappings once, not per method execution. Mappings should be defined at app start up and thereafter used.

public void UploadLDTTickets(LDTTicketUploadDTO[] ticketDTOs)
{
    Mapper.CreateMap<LDTTicketUploadDTO, LDTTicket>();
          .ForMember(d => d.SerialNumber, m => m.MapFrom(s => s.Ticket.SerialNumber))
              ...
    //Mapper.CreateMap<LDTTicketDTO, LDTTicket>(); You don't need this
    Mapper.CreateMap<LDTCustomerDTO, LDTCustomer>();
    Mapper.CreateMap<LDTDeviceDTO, LDTDevice>();

    ...
}