AutoMapper is a handy helper library to do mapping between objects. In most scenarios, you might have an Entity Class and you want to map it to some DTO class or vice versa. With minimal configuration, AutoMapper can do this mapping without you creating a method where you map each field one by one.
Suppose I have to map Entity class to EntityDto and they look like,
public class Entity
{
public string Name {get;set;}
public Guid Id {get;set;}
public string CurrencyCode {get;set;}
public decimal CurrencyValue {get;set;}
}
public class EntityDto
{
public string Name {get;set;}
public Guid Id {get;set;}
public Currency Currency {get;set;}
}
public class Currency
{
public string Code {get;set;}
public string Value {get;set;}
}using AutoMapper;
...
public class SomeService : ISomeService
{
private IMapper _iMapper;
public SomeService()
{
// One time configuration
var config = new MapperConfiguration(cfg =>
{
cfg.CreateMap<Entity, EntityDto>().ForMember(dto => dto.Currency, map => map.MapFrom(source => new Currency
{
Code = source.CurrencyCode,
Value = source.CurrencyValue.ToString("0.00")
}));
});
_iMapper = config.CreateMapper();
}
...
}
public async Task<DtoClass> GetAsync(Guid id)
{
Entity entity = await GetEntityByIdAsync(id);
// using auto mapper to do the mapping
var dto = _iMapper.Map<DtoClass>(entity);
return dto;
}In the mapping configuration, we didn't specify anything related Id, Name properties. AutoMapper will map them automatically since the source and destination property name matches for those.
Read more about the configuration and all on the official website of AutoMapper.
