Automapper

Description

Permet le mapping d'un objet de type A vers un objet de type B.
AutoMapper utilise des convention de mapping afin de réduire le paramétrage:

• Propriétés de même nom
• Flattening
• Ignore les références null

Liens

• Getting Started
• Static and Instance API
• AutoMapper.Collection bibliothèque externe pour géré les collections
• Map 1 object to list of objects

Setup and configuration

var config = new MapperConfiguration(cfg => { // configure mapping from Source to Dest cfg.CreateMap<Source, Dest>(); // load the configuration from AppProfile cfg.AddProfile<AppProfile>(); // load the configuration from all classes who inherits from Profile in the current assembly cfg.AddProfiles(typeof(ContainerConfig).Assembly); }); IMapper mapper = config.CreateMapper(); IMapper mapper = new Mapper(config);

• Configuration

Profile

AProfile.cs

internal sealed class AProfile : Profile { public AProfile() { this.CreateAToBMapping(); this.CreateBToAMapping(); } private void CreateAToBMapping() { this.CreateMap<A, B>() .ForMember(dest => dest.B1, opt => opt.MapFrom(src => src.A1)); } private void CreateBToAMapping() { this.CreateMap<B, A>() .ForMember(dest => dest.A1, opt => opt.MapFrom(src => src.B1));; } }

Dependency Injection

Add the nuget package AutoMapper.Extensions.Microsoft.DependencyInjection

Startup.cs

public void ConfigureServices(IServiceCollection services) { // add as parameter one type for each assembly services.AddAutoMapper(typeof(ProfileTypeFromAssembly1), typeof(ProfileTypeFromAssembly2));

Exemple

var config = new MapperConfiguration(cfg => { cfg.CreateMap<A, B>() .ForMember(dst => dst.Q2, opts => opts.MapFrom(src => src.P2)); // map A.P2 → B.Q2 .ReverseMap(); // map B → A }); IMapper mapper = config.CreateMapper(); C c = new C() { P1 = 3 }; A a = new A() { P1 = 1, C1 = c }; B b = mapper.Map<B>(a); // b.P1 = 1, b.Q2 = 2, b.C1P1 = 3 class A { public int P1 { get; set; } public int P2 { get; set; } public C C1 { get; set; } } class B { public int P1 { get; set; } // mapping par convention avec A.P1 public int Q2 { get; set; } // mapping par configuration avec A.P2 public int C1P1 { get; set; } // mapping par flattening avec A.C1.P1 } class C { public int P1 { get; set; } }

• Flattening

If the mapping has not been configured, you will get an AutoMapper.AutoMapperMappingException

List and polymorphism

// avec une liste List<B> listB = Mapper.Map<List<A>, List<B>>(listA); // polymorphism cfg.CreateMap<Parent1, Parent2>() .Include<Child1, Child2>(); // IncludeAllDerived(); to include all the derived classes // without the include, the resulting list contains only Parent2 objects (no Child2 objects) cfg.CreateMap<Child1, Child2>(); var lp1 = new List<Parent1> { new Parent1 { P1 = 1}, new Child1 { P1 = 2, P2 = 22 } }; var lp2 = mapper.Map<List<Parent2>>(lp1); // Parent2, Child2 class Parent1 { public int P1 { get; set; } } class Child1 : Parent1 { public int P2 { get; set; } } class Parent2 { public int P1 { get; set; } } class Child2 : Parent2 { public int P2 { get; set; } }

• Mapping Inheritance

Pass parameter to the mapping

var config = new MapperConfiguration(cfg => { cfg.CreateMap<A, B>() .ForMember(dest => dest.P1, opt => opt.MapFrom((src, dest, destMember, resContext) => src.P1 + (int)resContext.Items["+"])); }); IMapper mapper = config.CreateMapper(); var a = new A { P1 = 1 }; var b = mapper.Map<B>(a, opt => opt.Items["+"] = 9);

Map 1 object to multiple objects

var config = new MapperConfiguration(cfg => { cfg.CreateMap<D, FlatD>(); cfg.CreateMap<int, FlatD>() .ForMember(dest => dest.Id, opt => opt.MapFrom(src => src)); cfg.CreateMap<D, IEnumerable<FlatD>>() .ConvertUsing<DToFlatDConverter>(); }); IMapper mapper = config.CreateMapper(); var d = new D { Name = "D", Ids = { 1, 2, 3 } }; var flatDs = mapper.Map<IEnumerable<FlatD>>(d).ToList(); class DToFlatDConverter : ITypeConverter<D, IEnumerable<FlatD>> { public IEnumerable<FlatD> Convert( D source, IEnumerable<FlatD> destination, ResolutionContext context) { foreach (var id in source.Ids) { var flatD = context.Mapper.Map<FlatD>(id); context.Mapper.Map(source, flatD); yield return flatD; } } } class D { public string Name { get; set; } public ICollection<int> Ids { get; } = new List<int>(); } class FlatD { public string Name { get; set; } public int Id { get; set; } }

MOQ

var mapperMock = new Mock<IMapper>(); mapperMock.Setup(x => x.Map<ItemDto>(It.IsAny<Item>())) .Returns(new ItemDto());

Installation

NuGet → AutoMapper

ASP.NET Core

NuGet → AutoMapper.Extensions.Microsoft.DependencyInjection

Startup.cs

public void ConfigureServices(IServiceCollection services) { services.AddAutoMapper();

MyController.cs

private readonly IMapper _mapper; public MyController(IMapper mapper) { _mapper = mapper; B b = _mapper.Map<A, B>(a);

Configuration dans Profile