I am using auto mapping first time.
I am working on c# application and I want to use auto mapper.
(I just want to know how to use it, so I don't have asp.net app neither MVC app.)
I have three class library projects.
I want to write transfer process in the service project.
So I want to know how and where should I configure the Auto Mapper ?
So based on Bruno's answer here and John Skeet's post about singletons I came up with the following solution to have this run only once and be completely isolated in class library unlike the accepted answer which relies on the consumer of the library to configure the mappings in the parent project:
public static class Mapping
{
private static readonly Lazy<IMapper> Lazy = new Lazy<IMapper>(() =>
{
var config = new MapperConfiguration(cfg => {
// This line ensures that internal properties are also mapped over.
cfg.ShouldMapProperty = p => p.GetMethod.IsPublic || p.GetMethod.IsAssembly;
cfg.AddProfile<MappingProfile>();
});
var mapper = config.CreateMapper();
return mapper;
});
public static IMapper Mapper => Lazy.Value;
}
public class MappingProfile : Profile
{
public MappingProfile()
{
CreateMap<Source, Destination>();
// Additional mappings here...
}
}
Then in your code where you need to map one object to another you can just do:
var destination = Mapping.Mapper.Map<Destination>(yourSourceInstance);
NOTE: This code is based on AutoMapper 6.2 and it might require some tweaking for older versions of AutoMapper.
You can place the configuration anywhere:
public class AutoMapperConfiguration
{
public static void Configure()
{
Mapper.Initialize(x =>
{
x.AddProfile<MyMappings>();
});
}
}
public class MyMappings : Profile
{
public override string ProfileName
{
get { return "MyMappings"; }
}
protected override void Configure()
{
......
}
But it has to be called by the application using the libraries at some point:
void Application_Start()
{
AutoMapperConfiguration.Configure();
}
Nobody outside of your library has to configure AutoMapper
I recommend that you use the instance based approach using an IMapper. That way no one outside your library has to call any configuration method. You can define a MapperConfiguration and create the mapper from there all inside the class library.
var config = new MapperConfiguration(cfg => {
cfg.AddProfile<AppProfile>();
cfg.CreateMap<Source, Dest>();
});
IMapper mapper = config.CreateMapper();
// or
IMapper mapper = new Mapper(config);
var dest = mapper.Map<Source, Dest>(new Source());
Marko's answer is correct.
We can also go by a below simple solution.
public static class ObjectMapper
{
public static IMapper Mapper
{
get
{
return AutoMapper.Mapper.Instance;
}
}
static ObjectMapper()
{
CreateMap();
}
private static void CreateMap()
{
AutoMapper.Mapper.Initialize(cfg =>
{
cfg.CreateMap<SourceClass, DestinationClass>();
});
}
}
And we can use it like.
public class SourceClass
{
public string Name { get; set; }
}
public class DestinationClass
{
public string Name { get; set; }
}
SourceClass c1 = new SourceClass() { Name = "Mr.Ram" };
DestinationClass c2 = ObjectMapper.Mapper.Map<DestinationClass>(c1);
I have used the Patel Vishal's solution and customized it to my needs.
It's a generic class which makes sure only one instance of mapping is saved in memory per object mapping.
TModel - is a DTO object
TData - is a Database table object in Entity Framework
DTO.IBaseModel - is a base class for DTO object which has one property: ID
IBaseModel - is a base class for the entity framework database entity with ID property only
public static class ObjectMapper<TModel, TData>
where TModel : class, DTO.IBaseModel, new()
where TData : class, IBaseModel, new()
{
private static readonly MapperConfiguration _mapperConfiguration;
public static IMapper Mapper => new Mapper(_mapperConfiguration);
static ObjectMapper()
{
_mapperConfiguration ??= CreateMap();
}
private static MapperConfiguration CreateMap()
{
return new (cfg =>
{
cfg.CreateMap<TData, TModel>();
});
}
}
I am using this class in a BaseService<TData, TModel> (Service/Repository pattern) as such:
public virtual TModel Convert(TData t)
{
return ObjectMapper<TModel, TData>.Mapper.Map<TModel>(t);
}
As you can see, it's a virtual method. Mapping can be overwritten, if customization required by the inheriting Service.
I have come across this kind of requirement as well. What I have done in .Net 6.0 is, I create a library project and create the profile class:
public class AutoMapperProfile : Profile
{
public AutoMapperProfile()
{
CreateMap<Entity, Dto>();
CreateMap<Dto, Entity>();
......
}
}
while in the api or web project, I just create a child class to inherit from the profile above, and register it in startup.cs services.AddAutoMapper(typeof(Startup));.
Related
var config = new MapperConfiguration(cfg =>
{
cfg.CreateMap<SomeSourceModel, SomeDestinationModel>();
});
config.AssertConfigurationIsValid();
var mapper = config.CreateMapper();
I am repeating these code in the project. Thinking to create a common interface IMapper so that I can invoke whenever it is needed to be used.
The solution I create is
private IMapper Mapper(TSource source, TDestination dest)
{
var config = new MapperConfiguration(cfg =>
{
cfg.CreateMap<source, dest>();
});
config.AssertConfigurationIsValid();
return config.CreateMapper();
}
It doesn't work. The problem is I can't pass source model and destination model as parameters in this way. How to solve this?
Update 1:
As #12seconds mentioned, I start initializing MapperConfigration in Global.asax.cs
In App_Start folder, I created
public class MappingProfile : Profile
{
public MappingProfile()
{
CreateMap<SourceModel1, DestinationModel1>();
CreateMap<SourceModel2, DestinationModel2>();
CreateMap<SourceModel3, DestinationModel3>();
CreateMap<SourceModel4, DestinationModel4>();
CreateMap<SourceModel5, DestinationModel5>();
Mapper.AssertConfigurationIsValid();
}
}
In Global.asax.cs
public class AutoMapperConfiguration
{
public static void Configure()
{
Mapper.Initialize(x =>
{
x.AddProfile<MappingProfile>();
});
}
}
And then I tried to call AutoMapperConfiguration.Configure(); in several places. When I start running the App, I got same error messages:
Mapper not initialized. Call Initialize with appropriate
configuration. If you are trying to use mapper instances through a
container or otherwise, make sure you do not have any calls to the
static Mapper.Map methods, and if you're using ProjectTo or
UseAsDataSource extension methods, make sure you pass in the
appropriate IConfigurationProvider instance.
Where I suppose to call AutoMapperConfiguration.Configure();? Did I miss something?
Version 5.0.x +
public class AutoMapperConfiguration
{
public static void Configure()
{
Mapper.Initialize(x =>
{
x.AddProfile<MappingProfile>();
});
Mapper.AssertConfigurationIsValid();
}
}
The problem solved. Mapper.AssertConfigurationIsValid(); should be executed after Mapper initialized.
public class AutoMapperConfiguration
{
public static void Configure()
{
Mapper.Initialize(x =>
{
x.AddProfile<MappingProfile>();
});
Mapper.Configuration.AssertConfigurationIsValid();
}
}
I haveBusinessLayer, DTO library,DataService, EntityModel(wher EDMX sits), DTO library refers to both business and data layer. I am trying to implement automapper in data layer, want to map entity object to DTO object and return DTO from the dataService library.
Currently am doing this way
public class DataService
{
private MapperConfiguration config;
public DataService()
{
IMapper _Mapper = config.CreateMapper();
}
public List<Dto.StudentDto> Get()
{
using(var context = new DbContext().GetContext())
{
var studentList = context.Students.ToList();
config = new MapperConfiguration(cfg => {
cfg.CreateMap<Db.Student, Dto.StudentDto>();
});
var returnDto = Mapper.Map<List<Db.Student>, List<Dto.StudentDto>>(studentList);
return returnDto;
}
}
}
How can I move all the mappings to one class and automapper should initialize automatically when call to dataserive is made?
Is it good practice to use AutoMapper in data layer?
Yes.
How can I move all the mappings to one class and automapper should initialize automatically when call to dataserive is made?
You could just create a static class that creates the mappings once:
public static class MyMapper
{
private static bool _isInitialized;
public static Initialize()
{
if (!_isInitialized)
{
Mapper.Initialize(cfg =>
{
cfg.CreateMap<Db.Student, Dto.StudentDto>();
});
_isInitialized = true;
}
}
}
Make sure that you use this class in your data service:
public class DataService
{
public DataService()
{
MyMapper.Initialize();
}
public List<Dto.StudentDto> GetStudent(int id)
{
using (var context = new DbContext().GetContext())
{
var student = context.Students.FirstOrDefault(x => x.Id == id)
var returnDto = Mapper.Map<List<Dto.StudentDto>>(student);
return returnDto;
}
}
}
Dependending on how you actually host the DAL, you might be able to call the Initialize() method of your custom mapper class from the Main() method of an executable or from somewhere else than the constructor of your DataService class.
Use AutoMapper.Mapper.CreateMap on OnAppInitialize. You can do the implementation of course in an own static class for better style.
There is really no more magic in this - because you only have to register (CreateMap) the mappings one time.
initialize automatically when call to dataserive is made?
You can of course register it too in the constructor.
Here you can take a look at another sample - how to use register in one or two of many extended ways.
In the end AutoMapper should make your life easier and not harder. In my opinion the best way is to register everything at one point - when starting the application.
But you also can do it on demand like seperating each CreateMapin the constructor.
Both ways - just make sure you just call it once.
the error info :
Mapper not initialized. Call Initialize with appropriate
configuration. If you are trying to use mapper instances through a
container or otherwise, make sure you do not have any calls to the
static Mapper.Map methods, and if you're using ProjectTo or
UseAsDataSource extension methods, make sure you pass in the
appropriate IConfigurationProvider instance. InnerException:
StackTrace: at AutoMapper.Mapper.get_Configuration()
the asp.net mvc5 controller code
public override ActionResult Kendo_Read(DataSourceRequest request, IQueryable<Activity> results)
{
var data = results.ProjectTo<ActivityViewModel>();
var rdata = data.ToDataSourceResult(request);
return Json(rdata);
}
AutoMapper Configure Code
public class CRMProfile : Profile
{
CreateMap<Activity, ActivityViewModel>();
}
public static class Configuration
{
public static MapperConfiguration MapperConfiguration()
{
return new MapperConfiguration(x =>
{
x.AddProfile(new CRMProfile());
}
}
}
Register Code
internal static MapperConfiguration MapperConfiguration { get; private set; }
public class MvcApplication : System.Web.HttpApplication
{
MapperConfiguration = Configuration.MapperConfiguration();
}
i home return data type is IQueryable in the controller,not List,
I See the Question and Issue in stackoverflow but could not solved my problem.
From AutoMapper's source code you can see that this exception will be thrown when configuration is not initialized at all:
public static IConfigurationProvider Configuration
{
get => _configuration ?? throw new InvalidOperationException(InvalidOperationMessage);
private set => _configuration = value;
}
Make sure that Mapper is correctly configured using static properties or correctly registered using IoC container if you are using that (please, refer to documentation for details). Are you perhaps missing the Mapper.Initialize() call?
I am using AutoMapper profiles for mapping entities. In one of the mapping profiles I need to call a service method. I m trying to inject the service using profile constructor but then I m not able to register/add it. Any ideas how can I handle this?
public class HistoryProfile : Profile
{
private readonly MappingService _mappingService;
public HistoryProfile(MappingService mappingService)
{
_mappingService = mappingService;
this.CreateMap<HistoryCHR, History>()
.ForMember(h => h.BirthDate, hisChr => hisChr.MapFrom(x => x.DateOfBirth))
.....................
}
}
private static void InitializeSpecificProfiles()
{
Mapper.Initialize(
cfg =>
{
cfg.AddProfile(new HistoryProfile());
});
}
I have an Azure web job that parses CSV containing categories and maps the result into regular objects.
I'm trying to replicate AutoMapper + Simple Injector configuration from one project in another by memory but getting an error:
AutoMapper.AutoMapperMappingException : Missing type map configuration or unsupported mapping.
Mapping types:
CsvCategory -> Category
WebJobs.Data.CsvCategory -> Data.Category
Destination path:
Category
Source value:
WebJobs.Data.CsvCategory
container.RegisterSingleton<ITypeMapFactory, TypeMapFactory>();
container.RegisterCollection<IObjectMapper>(MapperRegistry.Mappers);
container.RegisterSingleton<ConfigurationStore>();
container.RegisterSingleton<IConfiguration, ConfigurationStore>();
container.RegisterSingleton<IConfigurationProvider, ConfigurationStore>();
container.RegisterSingleton<IMappingEngine>(Mapper.Engine);
Mapper.Initialize(c =>
{
c.ConstructServicesUsing(container.GetInstance);
c.AddProfile<CsvCategoryMappingProfile>();
});
public sealed class CsvCategoryMappingProfile : Profile
{
protected override void Configure() {
CreateMap<CsvCategory, Category>();
}
public override string ProfileName {
get { return typeof(CsvCategoryMappingProfile).Name; }
}
}
public sealed class MappingCategoryConverter : IConverter<CsvCategory, Category>
{
private readonly IMappingEngine _mapper;
public MappingCategoryConverter(IMappingEngine mapper)
{
_mapper = mapper;
}
public Category Convert(CsvCategory category)
{
return _mapper.Map<Category>(category);
}
}
I can fix it by replacing the whole container configuration with this line:
Mapper.AddProfile<CsvCategoryMappingProfile>();
but instead I'd like to learn where is the problem, where I'm doing this wrong.
I don't see how to use Mapper.Initialize() properly, the obvious way doesn't work.
Here's a workaround:
Mapper.Initialize(x =>
{
var config = container.GetInstance<IConfiguration>();
config.ConstructServicesUsing(container.GetInstance);
config.AddProfile<CsvCategoryMappingProfile>();
});
Because at x you're getting another instance of IConfiguration.