automapper automapping deep object to flat object and back

Question

How do you convert a deep object to a flat object and back using automapper?

for instance:

Person 
{
    public string Name { get; set; }
    public Address Address { get; set; }
}

Address
{
    public string City { get; set; }
    public string State { get; set; }
}

FlatObject
{
    public string Name { get; set; }
    public string City { get; set; }
    public string State { get; set; }
}

score 7 · Accepted Answer · edited May 23 '17 at 12:25

Two ways you could accomplish this:

Define two mappings, one from FlatObject --> Person and another from FlatObject --> Address:

Mapper.CreateMap<FlatObject, Address>();

Mapper.CreateMap<FlatObject, Person>()
    .ForMember(dest => dest.Address, opt => opt.MapFrom(src => src));

Define one mapping and create the Address object inside the mapping definition:

Mapper.CreateMap<FlatObject, Person>()
    .ForMember(
        dest => dest.Address, 
        opt => opt.MapFrom(
            src => new Address { City = src.City, State = src.State }));

Personally I'd go with option 1. This way if you add properties to FlatObject, you won't have to worry about updating the mapping definition (you would if you used option #2).

However, @Raphaël is correct in pointing out the author's link that questions the validity of mapping to domain objects.

score 2 · Answer 2 · answered Mar 09 '18 at 13:22

Starting from version 6.0.1 you can do with the ReverseMap method, wich is used to create the unflatten map.

Mapper
  .CreateMap<FlatObject, Person>()
  .ReverseMap();

This creates two maps, the flatten map is used to create the reversed one.

There is detailed info at the automapper documentation

score 0 · Answer 3 · answered Sep 06 '13 at 20:02

Well, AutoMapper is ok for "automatic" flattening, just respect the naming conventions, in your case

FlatObject {
  public string Name {get;set;}
  public string AddressCity {get;set;}
  public string AddressState {get;set;}
}

But AFAIK, AutoMapper doesn't do unflattening .

See this from the author of the library.

They're other tools that do that (with other kinds of limitations), like ValueInjecter

automapper automapping deep object to flat object and back

3 Answers3

Linked