Category: App Services

Adding AutoMapper to ASP.NET 6 application;

dotnet add package AutoMapper --version 10.1.1
dotnet add package AutoMapper.Extensions.Microsoft.DependencyInjection --version 8.1.1

The next step is adding the AutoMapper to our DI container, inside the program.cs we need to add the following;

builder.Services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());

Now its time to create our AutoMapper profiles, so on the root directory of our application we need to create AutoMapperProfile.cs

We are going to map the below entity (“User”) to the a Dto (“UserDto”)

public class User
    {
        public Guid Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Email { get; set; }
        public string Phone { get; set; }
        public DateTime DateOfBirth { get; set; }
        public string Country { get; set; }
        public string Address { get; set; }
        public string MobileNumber { get; set; }
        public string Sex { get; set; }
    }

public class UserDto
    {
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Email { get; set; }
        public string Phone { get; set; }
        public string DateOfBirth { get; set; }
        public string Country { get; set; }
    }
}

Now inside the AutoMapperProfile class we need to add the following

public class AutoMapperProfile : Profile
    {
        public AutoMapperProfile()
        {
            CreateMap<UserDto, User>()
                .ForMember(
                    dest => dest.FirstName,
                    opt => opt.MapFrom(src => $"{src.FirstName}")
                )
                .ForMember(
                    dest => dest.LastName,
                    opt => opt.MapFrom(src => $"{src.LastName}")
                )
                .ForMember(
                    dest => dest.Email,
                    opt => opt.MapFrom(src => $"{src.Email}")
                )
                .ForMember(
                    dest => Convert.ToDateTime(dest.DateOfBirth),
                    opt => opt.MapFrom(src => $"{src.DateOfBirth}")
                )
                .ForMember(
                    dest => dest.Phone,
                    opt => opt.MapFrom(src => $"{src.Phone}")
                )
                .ForMember(
                    dest => dest.Country,
                    opt => opt.MapFrom(src => $"{src.Country}")
                )
                .ForMember(
                    dest => dest.Status,
                    opt => opt.MapFrom(src => 1)
                );
        }
    }

The AutoMapperProfile class MUST inherit from Profile class in order for AutoMapper to recognise it.

Inside the constructor we define the mapping between the Entity and the Dto.

Once we complete our profile mapping its now to utilise our new map in our controller.

public class UsersController : ControllerBase
{
    public IUnitOfWork _unitOfWork;
    // define the mapper
    public readonly IMapper _mapper;

    // initialise the dependencies with constructor initialisation
    public UsersController(
        IMapper mapper,
        IUnitOfWork unitOfWork)
    {   
        _mapper = mapper;
        _unitOfWork = unitOfWork;
    }

    [HttpPost]
    public async Task<IActionResult> AddUser(UserDto user)
    {
        // utilise the mapping :)
        var _mappedUser = _mapper.Map<User>(user);

        await _unitOfWork.Users.Add(_mappedUser);
        await _unitOfWork.CompleteAsync();

        var result = new Result<UserDto>();
        result.Content = user;

        return CreatedAtRoute("GetUser", new { id = _mappedUser.Id}, result); // return a 201
    }
}

So basically we need to initialise the mapper with constructor initialisation.

Then we need to utilise as follow

var _mappedUser = _mapper.Map<Entity>(dto);

AutoMapper is a powerful tool to keep in our toolset.