Dismissile Dismissile - 3 months ago 73
C# Question

AutoMapper Map Child Property that also has a map defined

I have the following Domain Object:

public class DomainClass
{
public int Id { get; set; }

public string A { get; set; }
public string B { get; set; }
}


I have the following two objects that I want to map to:

public class Parent
{
public int Id { get; set; }
public string A { get; set; }

public Child Child { get; set; }
}

public class Child
{
public int Id { get; set; }
public string B { get; set; }
}


I set up the following maps:

Mapper.CreateMap<DomainClass, Parent>();
Mapper.CreateMap<DomainClass, Child>();


If I map my object using the following call then the parent.Child property is null.

var domain = GetDomainObject();
var parent = Mapper.Map<DomainClass, Parent>(domain); // parent.Child is null


I know I can write the following:

var domain = GetDomainObject();
var parent = Mapper.Map<DomainClass, Parent>(domain);
parent.Child = Mapper.Map<DomainClass, Child>(domain);


Is there a way I can eliminate that second call and have AutoMapper do this for me?

Answer

You just need to specify that in the mapping:

Mapper.CreateMap<DomainClass, Child>();
Mapper.CreateMap<DomainClass, Parent>()
      .ForMember(d => d.Id, opt => opt.MapFrom(s => s.Id))
      .ForMember(d => d.A, opt => opt.MapFrom(s => s.A))
      .ForMember(d => d.Child, 
                 opt => opt.MapFrom(s => Mapper.Map<DomainClass, Child>(s)));