Automapper: Can I use the same rule created by CreateMap to map both ways?

Question

I'm a little confuse about the direction of the mapping.

This is the create mapping.

Mapper.CreateMap<Dimension, PostedDimensionViewModel>()
            .ForMember(dto => dto.inputDimension, opt => opt.MapFrom(p => p.DimensionName))
            .ForMember(dto => dto.inputDescription, opt => opt.MapFrom(p => p.Description));

Then I can use it this way to go from PostedDimensionViewModel => Dimension:

Dimension dimension = Mapper.Map<PostedDimensionViewModel, Dimension>(model);

What if, I want to go from Dimension => PostedDimensionViewModel, do I need another CreateMap or I can just use the same above mapping from both directions?

Thanks for helping.

Answer 1

Just do this:

Mapper.CreateMap<Source, Destination>()
    /* your other stuff here */
    .ReverseMap();

There are limitations here, and I wouldn't recommend this except between two DTOs.

Answer 2

Yes, you'll need to provide an additional map if you intend to go in the other direction. If you try to use AutoMapper without the extra map you'll get an exception:

AutoMapperMappingException: Missing type map configuration or unsupported mapping.

Mapping types:

PostedDimensionViewModel -> Dimension