I need to have communication between 2 components. I created a class that goes:
public interface IApplicationState
{
string PlateNumber { get; }
event Action OnPlateInput;
void SetPlateNumber(string plateNumber);
}
public class ApplicationState : IApplicationState
{
public string? PlateNumber { get; private set; }
public event Action OnPlateInput;
public void SetPlateNumber(string plateNumber)
{
PlateNumber = plateNumber;
NotifyPlateNumberChanged();
}
private void NotifyPlateNumberChanged() => OnPlateInput?.Invoke();
}
Then registered it in my Program.cs
builder.Services.AddScoped(sp => new HttpClient
{
BaseAddress = new Uri(builder.HostEnvironment.BaseAddress)
});
builder.Services.AddSingleton<IApplicationState, ApplicationState>();
Then called it in 2 of my components:
public partial class SideWidgetComponent : ComponentBase
{
[Inject] ApplicationState ApplicationState { get; set; }
private string _plateNUmber = string.Empty;
public async Task SetPlateNumber()
{
await Task.Run(() =>
{
if (_plateNUmber == string.Empty) return;
ApplicationState?.SetPlateNumber(_plateNUmber);
});
}
}
partial class PlateListComponent : ComponentBase
{
[Inject] private HttpClient? HttpClient { get; set; }
[Inject] private ApplicationState ApplicationState { get; set; }
protected override async Task OnInitializedAsync()
{
ApplicationState.OnPlateInput += ApplicationState_OnPlateInput;
}
}
When I start the program I get an error of
Cannot provide a value for property 'ApplicationState' on type 'ALPR_WebUi.Client.Pages.HomeComponents.PlateListComponent'. There is no registered service of type 'ALPR_WebUi.Shared.ApplicationState'.
You have registered the interface IApplicationState in Program.cs, but are trying to inject ApplicationState, ie the concrete type. Since you didn't register the concrete type, it doesn't know how to resolve it.
So, either register the concrete type (ie ApplicationState without the I) or inject the interface. Either way will work.
In my application I am using Ninject and the NamedScopeExtension. One of the objects deeper in the object graph needs access to the root object that defined the named scope. It seems to me that DefinesNamedScope() does not also imply InNamedScope() and instead a new root object is created when I request the root.
Example:
using System;
using Ninject;
using Ninject.Extensions.NamedScope;
using Ninject.Syntax;
namespace NInjectNamedScope
{
public interface IScopeRoot
{
Guid Guid { get; }
void DoSomething();
}
public interface IFactory
{
Guid Guid { get; }
IOther CreateOther();
}
public interface IOther
{
void SayHello();
}
internal class ScopeRoot : IScopeRoot
{
private readonly IFactory m_factory;
private readonly IResolutionRoot m_kernel;
public Guid Guid { get; private set; }
public ScopeRoot(IFactory factory, IResolutionRoot kernel)
{
m_factory = factory;
m_kernel = kernel;
Guid = Guid.NewGuid();
}
public void DoSomething()
{
Console.WriteLine("ScopeRoot.DoSomething(): Entering");
Console.WriteLine("ScopeRoot GUID: {0}", Guid);
Console.WriteLine("IFactory GUID: {0}", m_factory.Guid);
var other = m_factory.CreateOther();
Console.WriteLine("ScopeRoot.DoSomething(): Other created");
other.SayHello();
Console.WriteLine("ScopeRoot.DoSomething(): Exiting");
}
}
internal class Factory : IFactory
{
private IResolutionRoot m_kernel;
public Guid Guid { get; private set; }
public Factory(IResolutionRoot kernel)
{
m_kernel = kernel;
Guid = Guid.NewGuid();
}
public IOther CreateOther()
{
return m_kernel.Get<IOther>();
}
}
internal class Other : IOther
{
private readonly IScopeRoot m_root;
private readonly IFactory m_factory;
public Other(IScopeRoot root, IFactory factory)
{
m_root = root;
m_factory = factory;
}
public void SayHello()
{
Console.WriteLine("Other.SayHello(): Hello");
Console.WriteLine("Our IScopeRoot has GUID: {0}", m_root.Guid);
Console.WriteLine("Our IFactory has GUID: {0}", m_factory.Guid);
}
}
public class MainClass
{
public static void Main(string[] args)
{
var kernel = new StandardKernel();
kernel.Bind<IScopeRoot>().To<ScopeRoot>().DefinesNamedScope("RootScope");
kernel.Bind<IFactory>().To<Factory>().InNamedScope("RootScope");
kernel.Bind<IOther>().To<Other>().InNamedScope("RootScope");
var root = kernel.Get<IScopeRoot>();
root.DoSomething();
Console.ReadKey();
}
}
}
In this example, Other is receiving the same instance of Factory as the root does, but a new instance of ScopeRoot is created instead of injecting the existing instance that defined the named scope.
How can I access the root of the named scope in a factory? Please note that this example is simplified. In reality, there are several layers of objects between the scope root and the factory method, so I cannot simply pass this to the factory.
Yes you're right, out of the box Ninject can't do .DefinesNamedScope().InNamedScope(). Except maybe for late "creation" (factory, lazy) this couldn't work anyway, because it would create a cyclic dependency.
The simplest way to achieve what you want is to create a "root of the root"... well just one class ActualRoot which is bound with DefinesNamedScope() and gets an IRootScope injected, which again will be bound with .InNamedScope(). The bad thing about this is, that you will need to inject/Get<> an ActualRoot instead of a IRootScope.
As far as i remember, what you can also do instead, is:
Bind<IRootScope>().To<RootScope>()
.InNamedScope(scopeName);
and then retrieve it as follows:
IResolutionRoot.Get<IRootScope>(new NamedScopeParameter(scopeName));
This way you don't need a DefinesNamedScope().
My DbContext implementation implements two interfaces.
I'm trying to follow best practices and instantiate one DbContext instance per HTTP request.
However, I have a controller action where I need to instantiate two classes, each of which takes different interface in constructor.
I am worried if in that scenario, for that specific action, two DbContext instances would be raised.
I've setup my ContainerBuilder like this:
builder.RegisterType<MyDbContext>()
.As<IWorkflowPersistenceStore>()
.As<IDocumentPersistenceStore>()
.InstancePerHttpRequest();
builder.RegisterType<WorkflowManager>().As<IWorkflowManager>().InstancePerHttpRequest();
builder.RegisterType<DocumentManager>().As<IDocumentManager>().InstancePerHttpRequest();
public class OperationController : Controller
{
private IWorkflowManager _workflowManager;
private IDocumentManager _documentManager;
public OperationController(IWorkflowManager workflowManager, IDocumentManager documentManager)
{
_workflowManager = workflowManager;
_documentManager = documentManager;
}
public ActionResult SaveWorkflowDocument(...)
{
// will my managers point to same DbContext?
_workflowManager.DoSomething(...);
_documentManager.DoSomethingElse(...);
return View();
}
}
public class WorkflowManager : IWorkflowManager
{
private IWorkflowPersistenceStore _store;
public WorkflowManager(IWorkflowPersistenceStore store)
{
_store = store;
}
}
public class DocumentManager : IDocumentManager
{
private IDocumentPersistenceStore _store;
public DocumentManager (IDocumentPersistenceStore store)
{
_store = store;
}
}
Is this good enough?
Do I have to add .SingleInstance()? I'm worried that it might create singleton for whole application.
I think you're ok with what you have. Test passes:
using Autofac;
using NUnit.Framework;
namespace AutofacTest
{
[TestFixture]
public class ScopeTest
{
[Test]
public void Test()
{
var builder = new ContainerBuilder();
builder.RegisterType<Component>()
.As<IServiceA>()
.As<IServiceB>()
.InstancePerLifetimeScope();
using (var container = builder.Build())
using (var scope = container.BeginLifetimeScope())
{
var a = scope.Resolve<IServiceA>();
var b = scope.Resolve<IServiceB>();
Assert.AreEqual(a, b);
}
}
}
public interface IServiceA { }
public interface IServiceB { }
public class Component : IServiceA, IServiceB { }
}
I have an MVC intranet application which uses EF 6. I have setup the DataAccess project in a separate class library which has EF 6 referenced. I have an entity which implements an interface:
public interface IAuditable
{
DateTime CreatedDateTime { get; set; }
string CreatedBy { get; set; }
}
public class Collection : IAuditable
{
// Properties
}
However, in the SaveChanges method I obviously don't have access to HttpContext.Current.User.Identity.Name as it is in a separate class library, so I was wondering how one would set this in SaveChanges?
public override int SaveChanges()
{
var addedEntries = ChangeTracker.Entries().Where(x => x.State == EntityState.Added);
foreach (var dbEntityEntry in addedEntries)
{
var entity = dbEntityEntry.Entity as IAuditable;
if (entity != null)
{
entity.CreatedDateTime = DateTime.Now;
// how do I set entity.CreatedBy = HttpContext.Current.User.Identity.Name?
}
}
return base.SaveChanges();
}
Edit
Following on from #CodeCaster solution, I have the following:
[BreezeController]
public class BreezeController : ApiController
{
private readonly BTNIntranetRepository _repository;
public BreezeController(BTNIntranetRepository repository)
{
_repository = repository;
_repository.LoggedInUser = HttpContext.Current.User.Identity.Name;
}
// Methods
}
But HttpContext.Current.User is null
This can be solved in many ways.
You're not really showing relevant code, but you can for example give the library class you expose a public string LoggedInUser (or ActingUser or give it a name) property which you set when instantiating it:
public class SomeController : Controller
{
private IDataSource _dataSource;
public SomeController(IDataSource dataSource)
{
_dataSource = dataSource;
_dataSource.LoggedInUser = HttpContext.Current.User.Identity.Name
}
}
You can then simply use that property in your IDataSource.SaveChanges() method:
public override int SaveChanges()
{
// ...
entity.CreatedBy = this.LoggedInUser;
}
I'm using AutoMapper in an ASP.NET MVC application. I was told that I should move the AutoMapper.CreateMap elsewhere as they have a lot of overhead. I'm not too sure how to design my application to put these calls in just 1 place.
I have a web layer, service layer and a data layer. Each a project of its own. I use Ninject to DI everything. I'll utilize AutoMapper in both web and service layers.
So what are your setup for AutoMapper's CreateMap? Where do you put it? How do you call it?
Doesn't matter, as long as it's a static class. It's all about convention.
Our convention is that each "layer" (web, services, data) has a single file called AutoMapperXConfiguration.cs, with a single method called Configure(), where X is the layer.
The Configure() method then calls private methods for each area.
Here's an example of our web tier config:
public static class AutoMapperWebConfiguration
{
public static void Configure()
{
ConfigureUserMapping();
ConfigurePostMapping();
}
private static void ConfigureUserMapping()
{
Mapper.CreateMap<User,UserViewModel>();
}
// ... etc
}
We create a method for each "aggregate" (User, Post), so things are separated nicely.
Then your Global.asax:
AutoMapperWebConfiguration.Configure();
AutoMapperServicesConfiguration.Configure();
AutoMapperDomainConfiguration.Configure();
// etc
It's kind of like an "interface of words" - can't enforce it, but you expect it, so you can code (and refactor) if necessary.
EDIT:
Just thought I'd mention that I now use AutoMapper profiles, so the above example becomes:
public static class AutoMapperWebConfiguration
{
public static void Configure()
{
Mapper.Initialize(cfg =>
{
cfg.AddProfile(new UserProfile());
cfg.AddProfile(new PostProfile());
});
}
}
public class UserProfile : Profile
{
protected override void Configure()
{
Mapper.CreateMap<User,UserViewModel>();
}
}
Much cleaner/more robust.
You can really put it anywhere as long as your web project references the assembly that it is in. In your situation I would put it in the service layer as that will be accessible by the web layer and the service layer and later if you decide to do a console app or you are doing a unit test project the mapping configuration will be available from those projects as well.
In your Global.asax you will then call the method that sets all of your maps. See below:
File AutoMapperBootStrapper.cs
public static class AutoMapperBootStrapper
{
public static void BootStrap()
{
AutoMapper.CreateMap<Object1, Object2>();
// So on...
}
}
Global.asax on application start
just call
AutoMapperBootStrapper.BootStrap();
Now some people will argue against this method violates some SOLID principles, which they have valid arguments. Here they are for the reading.
Configuring Automapper in Bootstrapper violates Open-Closed Principle?
Update: The approach posted here is no more valid as SelfProfiler has been removed as of AutoMapper v2.
I would take a similar approach as Thoai. But I would use the built-in SelfProfiler<> class to handle the maps, then use the Mapper.SelfConfigure function to initialize.
Using this object as the source:
public class User
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public DateTime BirthDate { get; set; }
public string GetFullName()
{
return string.Format("{0} {1}", FirstName, LastName);
}
}
And these as the destination:
public class UserViewModel
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
public class UserWithAgeViewModel
{
public int Id { get; set; }
public string FullName { get; set; }
public int Age { get; set; }
}
You can create these profiles:
public class UserViewModelProfile : SelfProfiler<User,UserViewModel>
{
protected override void DescribeConfiguration(IMappingExpression<User, UserViewModel> map)
{
//This maps by convention, so no configuration needed
}
}
public class UserWithAgeViewModelProfile : SelfProfiler<User, UserWithAgeViewModel>
{
protected override void DescribeConfiguration(IMappingExpression<User, UserWithAgeViewModel> map)
{
//This map needs a little configuration
map.ForMember(d => d.Age, o => o.MapFrom(s => DateTime.Now.Year - s.BirthDate.Year));
}
}
To initialize in your application, create this class
public class AutoMapperConfiguration
{
public static void Initialize()
{
Mapper.Initialize(x=>
{
x.SelfConfigure(typeof (UserViewModel).Assembly);
// add assemblies as necessary
});
}
}
Add this line to your global.asax.cs file: AutoMapperConfiguration.Initialize()
Now you can place your mapping classes where they make sense to you and not worry about one monolithic mapping class.
For those of you who adhere to the following:
using an ioc container
don't like to break open closed for this
don't like a monolithic config file
I did a combo between profiles and leveraging my ioc container:
IoC configuration:
public class Automapper : IWindsorInstaller
{
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.Register(Classes.FromThisAssembly().BasedOn<Profile>().WithServiceBase());
container.Register(Component.For<IMappingEngine>().UsingFactoryMethod(k =>
{
Profile[] profiles = k.ResolveAll<Profile>();
Mapper.Initialize(cfg =>
{
foreach (var profile in profiles)
{
cfg.AddProfile(profile);
}
});
profiles.ForEach(k.ReleaseComponent);
return Mapper.Engine;
}));
}
}
Configuration example:
public class TagStatusViewModelMappings : Profile
{
protected override void Configure()
{
Mapper.CreateMap<Service.Contracts.TagStatusViewModel, TagStatusViewModel>();
}
}
Usage example:
public class TagStatusController : ApiController
{
private readonly IFooService _service;
private readonly IMappingEngine _mapper;
public TagStatusController(IFooService service, IMappingEngine mapper)
{
_service = service;
_mapper = mapper;
}
[Route("")]
public HttpResponseMessage Get()
{
var response = _service.GetTagStatus();
return Request.CreateResponse(HttpStatusCode.Accepted, _mapper.Map<List<ViewModels.TagStatusViewModel>>(response));
}
}
The trade-off is that you have to reference the Mapper by the IMappingEngine interface instead of the static Mapper, but that's a convention I can live with.
All of above solutions provide a static method to call (from app_start or any where) that it should call other methods to configure parts of mapping-configuration. But, if you have a modular application, that modules may plug in and out of application at any time, these solutions does not work. I suggest using WebActivator library that can register some methods to run on app_pre_start and app_post_start any where:
// in MyModule1.dll
public class InitMapInModule1 {
static void Init() {
Mapper.CreateMap<User, UserViewModel>();
// other stuffs
}
}
[assembly: PreApplicationStartMethod(typeof(InitMapInModule1), "Init")]
// in MyModule2.dll
public class InitMapInModule2 {
static void Init() {
Mapper.CreateMap<Blog, BlogViewModel>();
// other stuffs
}
}
[assembly: PreApplicationStartMethod(typeof(InitMapInModule2), "Init")]
// in MyModule3.dll
public class InitMapInModule3 {
static void Init() {
Mapper.CreateMap<Comment, CommentViewModel>();
// other stuffs
}
}
[assembly: PreApplicationStartMethod(typeof(InitMapInModule2), "Init")]
// and in other libraries...
You can install WebActivator via NuGet.
In addition to the best answer, a good way is using Autofac IoC liberary to add some automation. With this you just define your profiles regardless of initiations.
public static class MapperConfig
{
internal static void Configure()
{
var myAssembly = Assembly.GetExecutingAssembly();
var builder = new ContainerBuilder();
builder.RegisterAssemblyTypes(myAssembly)
.Where(t => t.IsSubclassOf(typeof(Profile))).As<Profile>();
var container = builder.Build();
using (var scope = container.BeginLifetimeScope())
{
var profiles = container.Resolve<IEnumerable<Profile>>();
foreach (var profile in profiles)
{
Mapper.Initialize(cfg =>
{
cfg.AddProfile(profile);
});
}
}
}
}
and calling this line in Application_Start method:
MapperConfig.Configure();
The above code finds all Profile sub classes and initiate them automatically.
Putting all the mapping logic in 1 location is not a good practice for me. Because the mapping class will be extremely large and very hard to maintain.
I recommend put the mapping stuff together with the ViewModel class in the same cs file. You can easily navigate to the mapping definition you want following this convention. Moreover, while creating the mapping class, you can reference to the ViewModel properties faster since they are in the same file.
So your view model class will look like:
public class UserViewModel
{
public ObjectId Id { get; set; }
public string Firstname { get; set; }
public string Lastname { get; set; }
public string Email { get; set; }
public string Password { get; set; }
}
public class UserViewModelMapping : IBootStrapper // Whatever
{
public void Start()
{
Mapper.CreateMap<User, UserViewModel>();
}
}
From new version of AutoMapper using static method Mapper.Map() is deprecated. So you can add MapperConfiguration as static property to MvcApplication (Global.asax.cs) and use it to create instance of Mapper.
App_Start
public class MapperConfig
{
public static MapperConfiguration MapperConfiguration()
{
return new MapperConfiguration(_ =>
{
_.AddProfile(new FileProfile());
_.AddProfile(new ChartProfile());
});
}
}
Global.asax.cs
public class MvcApplication : System.Web.HttpApplication
{
internal static MapperConfiguration MapperConfiguration { get; private set; }
protected void Application_Start()
{
MapperConfiguration = MapperConfig.MapperConfiguration();
...
}
}
BaseController.cs
public class BaseController : Controller
{
//
// GET: /Base/
private IMapper _mapper = null;
protected IMapper Mapper
{
get
{
if (_mapper == null) _mapper = MvcApplication.MapperConfiguration.CreateMapper();
return _mapper;
}
}
}
https://github.com/AutoMapper/AutoMapper/wiki/Migrating-from-static-API
For those who are (lost) using:
WebAPI 2
SimpleInjector 3.1
AutoMapper 4.2.1 (With Profiles)
Here's how I managed integrating AutoMapper in the "new way". Also,
a Huge thanks to this answer(and question)
1 - Created a folder in the WebAPI project called "ProfileMappers". In this folder I place all my profiles classes which creates my mappings:
public class EntityToViewModelProfile : Profile
{
protected override void Configure()
{
CreateMap<User, UserViewModel>();
}
public override string ProfileName
{
get
{
return this.GetType().Name;
}
}
}
2 - In my App_Start, I have a SimpleInjectorApiInitializer which configures my SimpleInjector container:
public static Container Initialize(HttpConfiguration httpConfig)
{
var container = new Container();
container.Options.DefaultScopedLifestyle = new WebApiRequestLifestyle();
//Register Installers
Register(container);
container.RegisterWebApiControllers(GlobalConfiguration.Configuration);
//Verify container
container.Verify();
//Set SimpleInjector as the Dependency Resolver for the API
GlobalConfiguration.Configuration.DependencyResolver =
new SimpleInjectorWebApiDependencyResolver(container);
httpConfig.DependencyResolver = new SimpleInjectorWebApiDependencyResolver(container);
return container;
}
private static void Register(Container container)
{
container.Register<ISingleton, Singleton>(Lifestyle.Singleton);
//Get all my Profiles from the assembly (in my case was the webapi)
var profiles = from t in typeof(SimpleInjectorApiInitializer).Assembly.GetTypes()
where typeof(Profile).IsAssignableFrom(t)
select (Profile)Activator.CreateInstance(t);
//add all profiles found to the MapperConfiguration
var config = new MapperConfiguration(cfg =>
{
foreach (var profile in profiles)
{
cfg.AddProfile(profile);
}
});
//Register IMapper instance in the container.
container.Register<IMapper>(() => config.CreateMapper(container.GetInstance));
//If you need the config for LinqProjections, inject also the config
//container.RegisterSingleton<MapperConfiguration>(config);
}
3 - Startup.cs
//Just call the Initialize method on the SimpleInjector class above
var container = SimpleInjectorApiInitializer.Initialize(configuration);
4 - Then, in your controller just inject as usually a IMapper interface:
private readonly IMapper mapper;
public AccountController( IMapper mapper)
{
this.mapper = mapper;
}
//Using..
var userEntity = mapper.Map<UserViewModel, User>(entity);
For vb.net programmers using the new Version (5.x) of AutoMapper.
Global.asax.vb:
Public Class MvcApplication
Inherits System.Web.HttpApplication
Protected Sub Application_Start()
AutoMapperConfiguration.Configure()
End Sub
End Class
AutoMapperConfiguration:
Imports AutoMapper
Module AutoMapperConfiguration
Public MapperConfiguration As IMapper
Public Sub Configure()
Dim config = New MapperConfiguration(
Sub(cfg)
cfg.AddProfile(New UserProfile())
cfg.AddProfile(New PostProfile())
End Sub)
MapperConfiguration = config.CreateMapper()
End Sub
End Module
Profiles:
Public Class UserProfile
Inherits AutoMapper.Profile
Protected Overrides Sub Configure()
Me.CreateMap(Of User, UserViewModel)()
End Sub
End Class
Mapping:
Dim ViewUser = MapperConfiguration.Map(Of UserViewModel)(User)