自动映射，按命名约定映射

Question

I'm using automapper to map my entities. But entities have different structure.

Source:

public class SourceEntity
{
    public string Name { get; set; }
    public Type Type { get; set; }
    public Communication SelectedCommunication { get; set; }
}

public enum Type
{
    Type1=1,
    Typ2
}

[Flags]
public enum Communication
{
    Phone =1,
    Email =2,
    Post =4
}

Also I have HasFlag() extension method that will return true if flag is selected.

Destination entity:

public class DestinationEntity
{
    public string Name { get; set; }
    public bool Type1_PhoneSelected { get; set; }
    public bool Type1_EmailSelected { get; set; }
    public bool Type1_PostSelected { get; set; }
    public bool Type2_PhoneSelected { get; set; }
    public bool Type2_EmailSelected { get; set; }
    public bool Type2_PostSelected { get; set; }
}

My map:

        CreateMap<SourceEntity, DestinationEntity>()
            .ForMember(v => v.Name, opt => opt.MapFrom(i => i.Name));

But I can't figure out the best way to map Types properties. Is it possible to map it without typing something like:

.ForMemeber(v=>v.Test1_PhoneSelected, opt=>opt.MapFrom(i=>i.SelectedCommunication.HasFlag(Communication.Phone)))
.ForMemeber(v=>v.Test2_PhoneSelected, opt=>opt.MapFrom(i=>i.SelectedCommunication.HasFlag(Communication.Phone)))

For each of this properties. Is there any way to map by naming convention? Or any other ways?

Answer 1

You can use custom value resolvers

Although AutoMapper covers quite a few destination member mapping scenarios, there are the 1 to 5% of destination values that need a little help in resolving. Many times, this custom value resolution logic is domain logic that can go straight on our domain. However, if this logic pertains only to the mapping operation, it would clutter our source types with unnecessary behavior. In these cases, AutoMapper allows for configuring custom value resolvers for destination members.

Example of custom value resolver:

public class YourCustomResolver
    : IMemberValueResolver<object, object, Communication, bool>
{
    private Communication _communication;

    public YourCustomResolver(
        Communication communication)
    {
    }

    public bool Resolve(
        object source, 
        object destination,
        Communication sourceMember, 
        bool destMember, 
        ResolutionContext context)
    {
        return _communication == sourceMember;
    }
}

Your mapping will look like this:

CreateMap<SourceEntity, DestinationEntity>()
    .ForMember(dest => dest.Type1_PhoneSelected, opt => opt.ResolveUsing(new YourCustomResolver(Communication.Phone), src => src.SelectedCommunication))
    .ForMember(dest => dest.Type1_EmailSelected, opt => opt.ResolveUsing(new YourCustomResolver(Communication.Email), src => src.SelectedCommunication))
    .ForMember(dest => dest.Type1_PostSelected , opt => opt.ResolveUsing(new YourCustomResolver(Communication.Post) , src => src.SelectedCommunication))
    .ForMember(dest => dest.Type2_PhoneSelected, opt => opt.ResolveUsing(new YourCustomResolver(Communication.Phone), src => src.SelectedCommunication))
    .ForMember(dest => dest.Type2_EmailSelected, opt => opt.ResolveUsing(new YourCustomResolver(Communication.Email), src => src.SelectedCommunication))
    .ForMember(dest => dest.Type2_PostSelected , opt => opt.ResolveUsing(new YourCustomResolver(Communication.Post) , src => src.SelectedCommunication));