I'm currently working out of a .NET 5 class library project with no Startup methods.
The idea behind what I'm, trying to achieve is that a developer can tap into this library and pass in an object. This object will run through the method, AutoMapper will grab the properties that align with the properties in the FirstDTO, then return a DTO that can be used throughout any other projects.
I'm relatively new to the AutoMapper bits and found this article here: How to configure Auto mapper in class library project?
I've liked this approach and have leveraged it to map a dynamic object to a DTO:
Configuration.cs
public static class Configuration
{
private static readonly Lazy<IMapper> Lazy = new Lazy<IMapper>(() =>
{
var config = new MapperConfiguration(cfg =>
{
cfg.ShouldMapProperty = p => p.GetMethod.IsPublic || p.GetMethod.IsAssembly;
cfg.AddProfile<MappingProfile>();
});
IMapper mapper = config.CreateMapper();
return mapper;
});
public static IMapper Mapper => Lazy.Value;
}
Almost verbatim approach.
I have my MappingProfile.cs class:
public class MappingProfile : Profile
{
public MappingProfile()
{
CreateMap<dynamic, FirstDTO>();
CreateMap<dynamic, SecondDTO>();
}
}
When I call my base class I have the following method:
public class BaseLibraryClass : IBaseLibraryClass
{
public FirstDTO GetFirstObject(dynamic objectSentIn)
{
return Configuration.Mapper.Map<FirstDTO>(objectSentIn);
}
}
Which, in my though, should work.
Now when I write my xUnit unit tests, I'm having a failed Assert.Equal when comparing the FirstDTO with a built DTO:
private readonly IBaseLibraryClass baseLibraryClass = new BaseLibraryClass();
private readonly FirstDTOBuilder firstDTOBuilder = new FirstDTOBuilder();
[Fact]
public void TestSeparateObject()
{
// Arrange
FirstDTO firstDTO = firstDTOBuilder.DefaultDTO().Build();
// Act
FirstDTO result = baseLibraryClass.GetFirstObject(firstDTO);
// Assert
Assert.Equal(firstDTO, result);
}
What ends up happening when I debug this unit test, is that a DTO is built with the assigned properties via the Builder. It passes the DTO into GetFirstObject successfully with the populated properties, but when it hits the return, it returns a FirstDTO object type with properties that are all zeroed out, ultimately failing my unit test.
I feel like it's something glaringly obvious, but I cannot for the life of me figure out what's causing the properties to not map properly.
Any assistance would be greatly appreciated!
Automapper supports mapping from dynamic out of the box, no need to configure anything, so in your case removing profile from the configuration (or removing CreateMap's from the profile) should just work:
public static class Configuration
{
private static readonly Lazy<IMapper> Lazy = new Lazy<IMapper>(() =>
{
var config = new MapperConfiguration(cfg =>
{
cfg.ShouldMapProperty = p => p.GetMethod.IsPublic || p.GetMethod.IsAssembly;
});
IMapper mapper = config.CreateMapper();
return mapper;
});
public static IMapper Mapper => Lazy.Value;
}
I'm using Simple Injector as DI Container in a project.
The problem is that I have a SqliteStorage-class, which needs the path to the db. There are multiple dbs, so I need a way to inject the path to the SqliteStorage-class at creation.
My code looks as follows (simplified without interfaces):
public class SqliteStorageOptions
{
public string Path {get; set;}
}
public class SqliteStorage
{
private readonly string _path;
public SqliteStorage(SqliteStorageOptions options)
{
_path = options.Path;
}
}
public class Db1
{
private readonly SqliteStorage _sqlite;
public Db1(SqliteStorage sqlite)
{
_sqlite = sqlite;
}
}
public class Db2
{
private readonly SqliteStorage _sqlite;
public Db1(SqliteStorage sqlite)
{
_sqlite = sqlite;
}
}
// without di
var db1 = new Db1(new SqliteStorage(new SqliteStorageOptions { Path = "db1.db" });
var db2 = new Db2(new SqliteStorage(new SqliteStorageOptions { Path = "db2.db" });
Possible Solutions:
Include SqliteStorageOptions as parameter at every method in SqliteStorage.
Provide a init-method in SqliteStorage
Create a SqliteStorageFactory with a public SqliteStorage Create(SqliteStorageOptions options)-method.
So are there any built-in solution to my problem in simple-injector or can someone provide another (better) solution?
Thanks
Edit 1:
I added some code. Db1 and Db2 both connect to sqlite-dbs (different dbs, different schema), so I wanted to extract all the sqlite-stuff to its own class SqliteStorage. So, the SqliteStorage needs to know the db path.
Which solution is best depends a bit on whether you require Auto-Wiring (automatic constructor injection) or not. Using conditional registrations (using RegisterConditional) is a good pick, but you have be aware that it is limited to determining the injection based on only its direct parent. This means that you can't make SqliteStorageOptions conditional based on its parent parent (either Db1 or Db2).
If the Db1 and Db2 classes solely depend on a SqliteStorage and don't require any other dependencies, Auto-Wiring is not a real issue and your registrations can be as simple as the following:
container.Register<Db1>(
() => new Db1(new SqliteStorage(new SqliteStorageOptions { Path = "db1.db" }));
container.Register<Db2>(
() => new Db2(new SqliteStorage(new SqliteStorageOptions { Path = "db2.db" });
In case Auto-Wiring is required inside Db1 and Db2, RegisterConditional gives a good alternative, because it enables Auto-Wiring:
container.Register<Db1>();
container.Register<Db2>();
container.RegisterConditional<SqliteStorage>(
Lifestyle.CreateRegistration(
() => new SqliteStorage(new SqliteStorageOptions { Path = "db1.db" }),
container),
c => c.Consumer.ImplementationType == typeof(Db1));
container.RegisterConditional<SqliteStorage>(
Lifestyle.CreateRegistration(
() => new SqliteStorage(new SqliteStorageOptions { Path = "db2.db" }),
container),
c => c.Consumer.ImplementationType == typeof(Db2));
In this code snippet, both Db1 and Db2 are registered 'normally', while the SqliteStorage registrations are conditionally injected based on thei consumer.
This registration is more complex, because RegisterConditonal need to be supplied with a Registration instance: there is no RegisterConditional overload that directly accepts a Func<T> factory delegate.
You can have 2 singletons one per each database connection. Let's consider an example, firstly we'll need to create an interface for your StorageService:
public interface IStorage
{
void UsePath();
}
Now let's create couple of implementations of this storage service:
public class RedisStorage: IStorage
{
private readonly string _path;
public RedisStorage(string path)
{
_path = path;
}
public void UsePath()
{
Console.WriteLine($"Here's path: {_path}");
}
}
public class SqlStorage: IStorage
{
private readonly string _path;
public SqlStorage(string path)
{
_path = path;
}
public void UsePath()
{
Console.WriteLine($"Here's path: {_path}");
}
}
Enum to differentiate between implementations of IStorage:
public class StorageSource
{
public enum StorageTypes
{
Redis=1,
Sql=2
}
}
Once we are done with that, let's create a wrapper for a storage source:
public interface IStorageWrapper
{
void DoStuff();
}
Now comes a tricky part, instantiate a storage wrapper service decorator:
public class StorageServiceWrapper: IStorageWrapper
{
private readonly Func<string, IStorage> _storage;
public StorageServiceWrapper(Func<string, IStorage> storage)
{
_storage = storage;
}
public void UsePath()
{
_storage(StorageSource.StorageTypes.Redis.ToString()).DoStuff();
//uncomment for sql
//_storage(StorageSource.StorageTypes.Sql.ToString()).DoStuff();
}
}
To achieve this, you will need to register your classes in Startup.cs as follows:
services.AddScoped<IStorageWrapper, StorageServiceWrapper>();
services.AddSingleton<RedisStorage>();
services.AddSingleton<SqlStorage>();
services.AddTransient<Func<string, IStorage>>(serviceProvider => key =>
{
switch (key)
{
case "Redis":
return serviceProvider.GetService<RedisStorage>();
default:
return serviceProvider.GetService<SqlStorage>();
}
});
This wouldn't be as beautiful as calling _storage.DoStuff();, but I believe would help you with the solution of your problem. If you still want to keep it handy, consider managing your settings file and injecting proper IOptions<> instance with a conn string you need and registering a factory method.
I have the following configuration.
public class AutoMapperProfile: Profile
{
public AutoMapperProfile()
{
CreateMap<DTO, Model>();
CreateMap<InnerDTO, NavigationPropertyModel>();
}
}
In my code I have
Model.NavigationProperty = mapper.Map(DTO.InnerDTO, Model.NavigationProperty);
seems to work very well but
Model = mapper.Map(DTO, Model);
doesn't. (InnerDTO isn't mapped)
PS: mapper is an instance of the automapper.
I want to stick with the second approach since the DTO can have more properties than just the InnerDTO.
I tried using Mapper.AssertConfigurationIsValid(); but got an exception
System.InvalidOperationException: '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.'
Try to configure sub-property for CreateMap<DTO, Model>();.
public AutoMapperProfile()
{
CreateMap<DTO, Model>()
.ForMember(dest => dest.NavigationPropertyModel, opt => opt.MapFrom(src => src.InnerDTO));
CreateMap<InnerDTO, NavigationPropertyModel>();
}
Possibly what you are missing is to add your AutoMapperProfile class in Startup.cs.
public void ConfigureServices(IServiceCollection services) {
// Automapper conf
var config = new MapperConfiguration(configure => {
// Add your profile class here
configure.AddProfile(new AutoMapperProfile());
});
// Creating instance of automapper for dependency injection
var mapper = config.CreateMapper();
services.AddSingleton(mapper);
// More complex code here...
}
Subsequently, by dependency injection, you use automapper. In my particular case, I do it in the following way:
[Route("api/Permiso")]
[ApiController]
public class PermisoController : ControllerBase {
private readonly IMapper _mapper;
private readonly IBusinessLogicHelper _blh;
public PermisoController(BusinessLogicHelper blh, IMapper mapper) {
_blh = blh;
_mapper = mapper;
}
[HttpGet]
public IActionResult Get() {
try {
// Get raw data from entities
var resultsRaw = _blh.GetDataRaw();
if (resultsRaw == null) {
return NotFound();
}
// Mapping data from entity to DTO
var resultsDTO = _mapper.Map<ReturnDataDTO>(resultsRaw);
return Ok(resultsDTO);
} catch (Exception ex) {
// Custom ObjectResult for InternalServerError
return new InternalServerErrorObjectResult(ex.Message);
}
}
}
I'm relatively new at .NET, and I decided to tackle .NET Core instead of learning the "old ways". I found a detailed article about setting up AutoMapper for .NET Core here, but is there a more simple walkthrough for a newbie?
I figured it out! Here's the details:
Add the main AutoMapper Package to your solution via NuGet.
Add the AutoMapper Dependency Injection Package to your solution via NuGet.
Create a new class for a mapping profile. (I made a class in the main solution directory called MappingProfile.cs and add the following code.) I'll use a User and UserDto object as an example.
public class MappingProfile : Profile {
public MappingProfile() {
// Add as many of these lines as you need to map your objects
CreateMap<User, UserDto>();
CreateMap<UserDto, User>();
}
}
Then add the AutoMapperConfiguration in the Startup.cs as shown below:
public void ConfigureServices(IServiceCollection services) {
// .... Ignore code before this
// Auto Mapper Configurations
var mapperConfig = new MapperConfiguration(mc =>
{
mc.AddProfile(new MappingProfile());
});
IMapper mapper = mapperConfig.CreateMapper();
services.AddSingleton(mapper);
services.AddMvc();
}
To invoke the mapped object in code, do something like the following:
public class UserController : Controller {
// Create a field to store the mapper object
private readonly IMapper _mapper;
// Assign the object in the constructor for dependency injection
public UserController(IMapper mapper) {
_mapper = mapper;
}
public async Task<IActionResult> Edit(string id) {
// Instantiate source object
// (Get it from the database or whatever your code calls for)
var user = await _context.Users
.SingleOrDefaultAsync(u => u.Id == id);
// Instantiate the mapped data transfer object
// using the mapper you stored in the private field.
// The type of the source object is the first type argument
// and the type of the destination is the second.
// Pass the source object you just instantiated above
// as the argument to the _mapper.Map<>() method.
var model = _mapper.Map<UserDto>(user);
// .... Do whatever you want after that!
}
}
Step To Use AutoMapper with ASP.NET Core.
Step 1. Installing AutoMapper.Extensions.Microsoft.DependencyInjection from NuGet Package.
Step 2. Create a Folder in Solution to keep Mappings with Name "Mappings".
Step 3. After adding Mapping folder we have added a class with Name "MappingProfile" this name can anything unique and good to understand.
In this class, we are going to Maintain all Mappings.
Step 4. Initializing Mapper in Startup "ConfigureServices"
In Startup Class, we Need to Initialize Profile which we have created and also Register AutoMapper Service.
Mapper.Initialize(cfg => cfg.AddProfile<MappingProfile>());
services.AddAutoMapper();
Code Snippet to show ConfigureServices Method where we need to Initialize and Register AutoMapper.
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
public void ConfigureServices(IServiceCollection services)
{
services.Configure<CookiePolicyOptions>(options =>
{
// This lambda determines whether user consent for non-essential cookies is needed for a given request.
options.CheckConsentNeeded = context => true;
options.MinimumSameSitePolicy = SameSiteMode.None;
});
// Start Registering and Initializing AutoMapper
Mapper.Initialize(cfg => cfg.AddProfile<MappingProfile>());
services.AddAutoMapper();
// End Registering and Initializing AutoMapper
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
}}
Step 5. Get Output.
To Get Mapped result we need to call AutoMapper.Mapper.Map and pass Proper Destination and Source.
AutoMapper.Mapper.Map<Destination>(source);
CodeSnippet
[HttpPost]
public void Post([FromBody] SchemeMasterViewModel schemeMaster)
{
if (ModelState.IsValid)
{
var mappedresult = AutoMapper.Mapper.Map<SchemeMaster>(schemeMaster);
}
}
I want to extend #theutz's answers - namely this line :
// services.AddAutoMapper(typeof(Startup)); // <-- newer automapper version uses this signature.
There is a bug (probably) in AutoMapper.Extensions.Microsoft.DependencyInjection version 3.2.0. (I'm using .NET Core 2.0)
This is tackled in this GitHub issue. If your classes inheriting AutoMapper's Profile class exist outside of assembly where you Startup class is they will probably not be registered if your AutoMapper injection looks like this:
services.AddAutoMapper();
unless you explicitly specify which assemblies to search AutoMapper profiles for.
It can be done like this in your Startup.ConfigureServices:
services.AddAutoMapper(<assembies> or <type_in_assemblies>);
where "assemblies" and "type_in_assemblies" point to the assembly where Profile classes in your application are specified. E.g:
services.AddAutoMapper(typeof(ProfileInOtherAssembly), typeof(ProfileInYetAnotherAssembly));
I suppose (and I put emphasis on this word) that due to following implementation of parameterless overload (source code from GitHub) :
public static IServiceCollection AddAutoMapper(this IServiceCollection services)
{
return services.AddAutoMapper(null, AppDomain.CurrentDomain.GetAssemblies());
}
we rely on CLR having already JITed assembly containing AutoMapper profiles which might be or might not be true as they are only jitted when needed (more details in this StackOverflow question).
theutz' answer here is very good, I just want to add this:
If you let your mapping profile inherit from MapperConfigurationExpression instead of Profile, you can very simply add a test to verify your mapping setup, which is always handy:
[Fact]
public void MappingProfile_VerifyMappings()
{
var mappingProfile = new MappingProfile();
var config = new MapperConfiguration(mappingProfile);
var mapper = new Mapper(config);
(mapper as IMapper).ConfigurationProvider.AssertConfigurationIsValid();
}
I solved it this way (similar to above but I feel like it's a cleaner solution) Works with .NET Core 3.x
Create MappingProfile.cs class and populate constructor with Maps (I plan on using a single class to hold all my mappings)
public class MappingProfile : Profile
{
public MappingProfile()
{
CreateMap<Source, Dest>().ReverseMap();
}
}
In Startup.cs, add below to add to DI (the assembly arg is for the class that holds your mapping configs, in my case, it's the MappingProfile class).
//add automapper DI
services.AddAutoMapper(typeof(MappingProfile));
In Controller, use it like you would any other DI object
[Route("api/[controller]")]
[ApiController]
public class AnyController : ControllerBase
{
private readonly IMapper _mapper;
public AnyController(IMapper mapper)
{
_mapper = mapper;
}
public IActionResult Get(int id)
{
var entity = repository.Get(id);
var dto = _mapper.Map<Dest>(entity);
return Ok(dto);
}
}
I like a lot of answers, particularly #saineshwar 's one. I'm using .net Core 3.0 with AutoMapper 9.0, so I feel it's time to update its answer.
What worked for me was in Startup.ConfigureServices(...) register the service in this way:
services.AddAutoMapper(cfg => cfg.AddProfile<MappingProfile>(),
AppDomain.CurrentDomain.GetAssemblies());
I think that rest of #saineshwar answer keeps perfect. But if anyone is interested my controller code is:
[HttpGet("{id}")]
public async Task<ActionResult> GetIic(int id)
{
// _context is a DB provider
var Iic = await _context.Find(id).ConfigureAwait(false);
if (Iic == null)
{
return NotFound();
}
var map = _mapper.Map<IicVM>(Iic);
return Ok(map);
}
And my mapping class:
public class MappingProfile : Profile
{
public MappingProfile()
{
CreateMap<Iic, IicVM>()
.ForMember(dest => dest.DepartmentName, o => o.MapFrom(src => src.Department.Name))
.ForMember(dest => dest.PortfolioTypeName, o => o.MapFrom(src => src.PortfolioType.Name));
//.ReverseMap();
}
}
----- EDIT -----
After reading the docs linked in the comments by Lucian Bargaoanu, I think it's better to change this answer a bit.
The parameterless services.AddAutoMapper() (that had the #saineshwar answer) doesn't work anymore (at least for me). But if you use the NuGet assembly AutoMapper.Extensions.Microsoft.DependencyInjection, the framework is able to inspect all the classes that extend AutoMapper.Profile (like mine, MappingProfile).
So, in my case, where the class belong to the same executing assembly, the service registration can be shortened to services.AddAutoMapper(System.Reflection.Assembly.GetExecutingAssembly());
(A more elegant approach could be a parameterless extension with this coding).
Thanks, Lucian!
At the latest versions of asp.net core you should use the following initialization:
services.AddAutoMapper(typeof(YourMappingProfileClass));
In my Startup.cs (Core 2.2, Automapper 8.1.1)
services.AddAutoMapper(new Type[] { typeof(DAL.MapperProfile) });
In my data access project
namespace DAL
{
public class MapperProfile : Profile
{
// place holder for AddAutoMapper (to bring in the DAL assembly)
}
}
In my model definition
namespace DAL.Models
{
public class PositionProfile : Profile
{
public PositionProfile()
{
CreateMap<Position, PositionDto_v1>();
}
}
public class Position
{
...
}
For AutoMapper 9.0.0:
public static IEnumerable<Type> GetAutoMapperProfilesFromAllAssemblies()
{
foreach (var assembly in AppDomain.CurrentDomain.GetAssemblies())
{
foreach (var aType in assembly.GetTypes())
{
if (aType.IsClass && !aType.IsAbstract && aType.IsSubclassOf(typeof(Profile)))
yield return aType;
}
}
}
MapperProfile:
public class OrganizationProfile : Profile
{
public OrganizationProfile()
{
CreateMap<Foo, FooDto>();
// Use CreateMap... Etc.. here (Profile methods are the same as configuration methods)
}
}
In your Startup:
services.AddAutoMapper(GetAutoMapperProfilesFromAllAssemblies()
.ToArray());
In Controller or service:
Inject mapper:
private readonly IMapper _mapper;
Usage:
var obj = _mapper.Map<TDest>(sourceObject);
Need to install a package for setting up the automapper.
dotnet add package AutoMapper.Extensions.Microsoft.DependencyInjection
After the AddAutoMapper will be available in services.
public void ConfigureServices(IServiceCollection services)
{
services.AddAutoMapper(typeof(Startup));
}
Create mapper from Employee class to EmployeeDTO.
using AutoMapper;
public class AutomapperProfile: Profile
{
public AutomapperProfile()
{
//Source to destination.
CreateMap<Employee,EmployeeDTO>();
}
}
EmployeeController maps from Employee to EmployeeDTo
using System.Collections.Generic;
using AutoMapper;
using Microsoft.AspNetCore.Mvc;
[Route("api/[controller]")]
[ApiController()]
public class EmployeeController : ControllerBase
{
private readonly IMapper _mapper;
public EmployeeController(IMapper mapper)
{
_mapper = mapper;
}
[HttpGet]
public IEnumerable<EmployeeDTO> GetEmployees()
{
/*
Assume it to be a service call/database call
it returns a list of employee, and now we will map it to EmployeeDTO
*/
var employees = Employee.SetupEmployee();
var employeeDTO = _mapper.Map<IEnumerable<EmployeeDTO>>(employees);
return employeeDTO;
}
}
Employee.cs for reference
using System.Collections.Generic;
public class Employee
{
public int EmployeeId { get; set; }
public string EmployeeName { get; set; }
public int Salary { get; set; }
public static IEnumerable<Employee> SetupEmployee()
{
return new List<Employee>()
{
new Employee(){EmployeeId = 1, EmployeeName ="First", Salary=10000},
new Employee(){EmployeeId = 2, EmployeeName ="Second", Salary=20000},
new Employee(){EmployeeId = 3, EmployeeName ="Third", Salary=30000},
new Employee(){EmployeeId = 4, EmployeeName ="Fourth", Salary=40000},
new Employee(){EmployeeId = 5, EmployeeName ="Fifth", Salary=50000}
};
}
}
EmployeeDTO.cs for reference
public class EmployeeDTO
{
public int EmployeeId { get; set; }
public string EmployeeName { get; set; }
}
I am using AutoMapper 6.1.1 and asp.net Core 1.1.2.
First of all, define Profile classes inherited by Profile Class of Automapper. I Created IProfile interface which is empty, the purpose is only to find the classes of this type.
public class UserProfile : Profile, IProfile
{
public UserProfile()
{
CreateMap<User, UserModel>();
CreateMap<UserModel, User>();
}
}
Now create a separate class e.g Mappings
public class Mappings
{
public static void RegisterMappings()
{
var all =
Assembly
.GetEntryAssembly()
.GetReferencedAssemblies()
.Select(Assembly.Load)
.SelectMany(x => x.DefinedTypes)
.Where(type => typeof(IProfile).GetTypeInfo().IsAssignableFrom(type.AsType()));
foreach (var ti in all)
{
var t = ti.AsType();
if (t.Equals(typeof(IProfile)))
{
Mapper.Initialize(cfg =>
{
cfg.AddProfiles(t); // Initialise each Profile classe
});
}
}
}
}
Now in MVC Core web Project in Startup.cs file, in the constructor, call Mapping class which will initialize all mappings at the time of application
loading.
Mappings.RegisterMappings();
In .NET 6 you'll need to add the following to the Program.cs file:
builder.Services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());
For ASP.NET Core (tested using 2.0+ and 3.0), if you prefer to read the source documentation:
https://github.com/AutoMapper/AutoMapper.Extensions.Microsoft.DependencyInjection/blob/master/README.md
Otherwise following these 4 steps works:
Install AutoMapper.Extensions.Microsoft.DependancyInjection from nuget.
Simply add some profile classes.
Then add below to your startup.cs class.
services.AddAutoMapper(OneOfYourProfileClassNamesHere)
Then simply Inject IMapper in your controllers or wherever you need it:
public class EmployeesController {
private readonly IMapper _mapper;
public EmployeesController(IMapper mapper){
_mapper = mapper;
}
And if you want to use ProjectTo its now simply:
var customers = await dbContext.Customers.ProjectTo<CustomerDto>(_mapper.ConfigurationProvider).ToListAsync()
Let’s have a look at how to add Auto mapper into our .NET Core application.
step: 1
The first step is to install the corresponding NuGet package:
Install-Package AutoMapper.Extensions.Microsoft.DependencyInjection
step: 2
After installing the required package, the next step is to configure the services. Let’s do it in the Startup.cs class:
public void ConfigureServices(IServiceCollection services)
{
services.AddAutoMapper(typeof(Startup));
services.AddControllersWithViews();
}
step: 3
Let’s start usage we have a domain object named User:
public class User
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Email { get; set; }
public string Address { get; set; }
}
In the UI layer, we would have a View Model to display the user information:
public class UserViewModel
{
public string FirstName { get; set; }
public string LastName { get; set; }
public string Email { get; set; }
}
step: 4
A good way to organize our mapping configurations is with Profiles. We need to create classes that inherit from Profile class and put the configuration in the constructor:
public UserProfile()
{
CreateMap<User, UserViewModel>();
}
step: 5
Now, let’s define a Controller and use the Auto-Mapping capabilities that we just added:
public class UserController : Controller
{
private readonly IMapper _mapper;
public UserController(IMapper mapper)
{
_mapper = mapper;
}
public IActionResult Index()
{
// Populate the user details from DB
var user = GetUserDetails();
UserViewModel userViewModel = _mapper.Map<UserViewModel>(user);
return View(userViewModel);
}
}
First, we inject the mapper object into the controller. Then, we call the Map() method, which maps the User object to the UserViewModel object. Furthermore, pay attention to a local method GetUserDetails that we use for the local data storage.
You can find its implementation in our source code.
Asp.Net Core 2.2 with AutoMapper.Extensions.Microsoft.DependencyInjection.
public class MappingProfile : Profile
{
public MappingProfile()
{
CreateMap<Domain, DomainDto>();
}
}
In Startup.cs
services.AddAutoMapper(typeof(List.Handler));
services.AddAutoMapper(); didn't work for me. (I am using Asp.Net Core 2.0)
After configuring as below
var config = new AutoMapper.MapperConfiguration(cfg =>
{
cfg.CreateMap<ClientCustomer, Models.Customer>();
});
initialize the mapper
IMapper mapper = config.CreateMapper();
and add the mapper object to services as a singleton
services.AddSingleton(mapper);
this way I am able to add a DI to controller
private IMapper autoMapper = null;
public VerifyController(IMapper mapper)
{
autoMapper = mapper;
}
and I have used as below in my action methods
ClientCustomer customerObj = autoMapper.Map<ClientCustomer>(customer);
To add onto what Arve Systad mentioned for testing. If for whatever reason you're like me and want to maintain the inheritance structure provided in theutz solution, you can set up the MapperConfiguration like so:
var mappingProfile = new MappingProfile();
var config = new MapperConfiguration(cfg =>
{
cfg.AddProfile(mappingProfile);
});
var mapper = new Mapper(config);
I did this in NUnit.
For AutoMapper 11.0.1 using .NET 7 I started getting this exception:
System.ArgumentException: 'GenericArguments[0], 'System.DateTime', on 'T MaxInteger[T](System.Collections.Generic.IEnumerable`1[T])' violates the constraint of type 'T'.'
Inner Exception
VerificationException: Method System.Linq.Enumerable.MaxInteger: type argument 'System.DateTime' violates the constraint of type parameter 'T'.
See this question:
System.DateTime on 'T MaxInteger[T](System.Collections.Generic.IEnumerable`1[T])' violates the constraint of type T for .NET 7 using AutoMapper 11.0.1
This meant that I could no longer use services.AddAutoMapper(typeof(MappingProfile).Assembly); without an exception.
For AutoMapper.Extensions.Microsoft.DependencyInjection I solved it like this:
services.AddAutoMapper(cfg => cfg.Internal().MethodMappingEnabled = false, typeof(MappingProfile).Assembly);
For Blazor WebAssembly client the solution looked like this:
var mapperConfig = new MapperConfiguration(mc =>
{
//Needed for https://github.com/AutoMapper/AutoMapper/issues/3988
mc.Internal().MethodMappingEnabled = false;
mc.AddProfile(new MappingProfile());
});
//mapperConfig.AssertConfigurationIsValid();
IMapper mapper = mapperConfig.CreateMapper();
builder.Services.AddSingleton(mapper);
about theutz answer ,
there is no need to specify the IMapper mapper parrameter at the controllers constructor.
you can use the Mapper as it is a static member at any place of the code.
public class UserController : Controller {
public someMethod()
{
Mapper.Map<User, UserDto>(user);
}
}
I have a service defined like this:
public class MentorService : IMentorService
{
private readonly Func<MentorContext> _dbFactory;
public MentorService(string connectionString)
{
this._dbFactory = () => new MentorContext(connectionString);
}
public MentorService()
{
this._dbFactory = () => new MentorContext();
}
public MentorContext CreateContext()
{
return _dbFactory.Invoke();
}
public IList<User> GetUsers()
{
using (var db = CreateContext())
{
return db.Users.ToList();
}
}
// etc etc
}
Within my API controllers, I have the following:
public class UserController : ApiController
{
private readonly IMentorService _mentorService;
public UserController()
{
_mentorService = new MentorService();
}
public UserController(IMentorService mentorService)
{
_mentorService = mentorService;
}
}
I'd like to break the service up into sub-services for easier maintenance and testing - something like UserService, BookService, etc. Then I just want to use a single service in my controllers.
How can this be done?
I am a huge fan of factories for this sort of thing.
(Please note, I am assuming you have some sort of DI/IoC setup, considering you have an interface-based example)
Basically, you first split your code into separate classes UserService, BookService, etc. Once you've done that, you create a factory that creates these services for you. Something like this:
public class UserControllerServiceFactory : IUserControllerServiceFactory {
public IUserService CreateUserService() {
return _container.Get<IUserService>();
}
public IBookService CreateBookService() {
return _container.Get<IBookService>();
}
// etc.
}
We use Ninject for our DI/IoC, and prefer to use the Factories extensions for Ninject. This means we don't have to implement the factories ourselves.. we only define the interfaces.
Then you have the factory injected into your controller:
public UserController(IUserControllerServiceFactory factory) {
_factory = factory;
}
And then, your Action Methods use the factory to access the services you require:
[HttpGet]
public ActionResult ViewAllBooks() {
return View(_factory.CreateBookService().GetAll());
}
etc.
I hope that is what you meant.