I am new to DI concept and new to structuremap. I am trying to full fill a scenario where all my interfaces are in AssemblyA and all my implementations are in AssemblyB. I want to use Structuremap to inject instance of AssemblyB class in constructor which has dependency on interface from AssemblyA
public class Customer(ICustomerService)
{
}
ICustomerService is in AssemblyA and CustomerService class is in assemblyB. I want Structuremap to inject CustomerService instance in this constructor. I am assuming that if the name of class is same as the name of interface prefixed with and I. Structuremap will recognize it automatically.
I have written the following configuration.
x =>
{
x.Scan(scan =>
{
scan.Assembly("AssemblyA");
scan.Assembly("AssemblyB");
scan.TheCallingAssembly();
scan.WithDefaultConventions();
});
but it gives me error
StructureMap Exception Code: 202
No Default Instance defined for PluginFamily AssemblyA.ICustomerService, AssemblyA, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
I want to use the default conventions and avoid registering each interface to a class.
Ok, I got it to work but I am even more confused now.
This code seems to work
IContainer container = new Container(c =>
{
c.Scan(x =>
{
x.Assembly("AssemblyA");
x.Assembly("AssemblyB");
x.IncludeNamespace("AssemblyA");
x.TheCallingAssembly();
x.WithDefaultConventions();
});
});
Here I have simple added x.IncludeNamespace("AssemblyA"); after the AssemblyB scan thinking that it needs this namespace and it has started working.
My problem is solved but I don't know what was wrong or if this is the right way to go. Any help will still be greatly appreciated.
Related
I'm still trying to get my head around what's what with ASP.NET 5 / EF 7. I'm using DNX projects (.xproj).
Startup is used by OWIN/ASP.NET for configuring, loading services, etc. But it's also used for EF 7 migrations (to set your DbContextOptions for example).
My main goal is to know how EF7 (and ASP.NET 5) bootstrap with Startup and who's creating the startup class, initializing the DI container, etc.
An example of what I need to do, for context, is that in my xUnit unit tests (which are in their own assembly and reference my data assembly which doesn't have a Startup class), I need to AddDbContext to set my connection.
I have the sample startup class:
namespace Radar.Data
{
using Microsoft.AspNet.Builder;
using Microsoft.AspNet.Hosting;
using Microsoft.Data.Entity;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.PlatformAbstractions;
public class Startup
{
public IConfigurationRoot Configuration { get; set; }
public Startup(IHostingEnvironment env, IApplicationEnvironment appEnv)
{
var builder = new ConfigurationBuilder()
.SetBasePath(appEnv.ApplicationBasePath)
.AddJsonFile("appsettings.json");
Configuration = builder.Build();
}
public void ConfigureServices(IServiceCollection services)
{
services.AddEntityFramework()
.AddSqlServer()
.AddDbContext<RadarDbContext>(options =>
options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"]));
}
public void Configure(IApplicationBuilder app)
{
}
}
}
This is currently in my data assembly and not my unit test assembly. I tried adding the app setting (I know it's OWIN but I thought I'd give it a shot):
<appSettings>
<add key="owin:appStartup" value="Radar.Data.Startup, Radar.Data" />
</appSettings>
The startup class is not getting executed.
I'd really like an understanding of the overall mechanism with Startup, who calls it, etc., but for now, I just need an understanding of how EF 7 initializes dependencies/services so that I can properly initialize my unit tests.
UPDATE
Here's what I've got in my unit test so far and I thought I had it working at one point:
ServiceCollection serviceCollection = new ServiceCollection();
IServiceProvider serviceProvider = serviceCollection.BuildServiceProvider();
DbContextActivator.ServiceProvider = serviceProvider;
serviceCollection.AddEntityFramework()
.AddSqlServer()
.AddDbContext<RadarDbContext>(
options => options.UseSqlServer("Server=.;Database=SonOfRadar;Trusted_Connection=True;MultipleActiveResultSets=True"));
but now I'm getting No service for type 'Microsoft.Data.Entity.Internal.IDbSetInitializer' has been registered when my DbContext is instantiated. So obviously not getting all the EF services loaded.
If I comment out:
DbContextActivator.ServiceProvider = serviceProvider;
it errors earlier with: No database providers are configured. Configure a database provider by overriding OnConfiguring in your DbContext class or in the AddDbContext method when setting up services.
Setting DbContextActivator.ServiceProvider is the only place in EF7 where I can find a hook to set your own provider. I'd be just as happy getting an instance of EF7's internal service collection and working with that. I think I'm going to scour the EF7 unit test code again and see if I'm missing a critical piece.
Startup class is created by Microsoft.AspNet.Hosting package when you run you web application (see StartupLoader.cs).
You can also look onto WebApplication.Run method (WebApplication.Run) its an entry point to ASP.NET 5 web applications.
DI is initialized in WebHostBuilder class (WebHostBuilder.cs) and inside dnx in Bootstrapper class (Bootstrapper.cs)
I want to create instance of PerRequestResourceProvider using ninject InRequestScope:
public class PerRequestResourceProvider: IPerRequestResourceProvider
{
priavte readonly _perRequestResorceInstance;
public PerRequestResourceProvider()
{
_perRequestResorceInstance = new PerRequestResource();
}
public PerRequestResource GetResource()
{
return _perRequestResorceInstance;
}
}
public interface IPerRequestResourceProvider
{
PerRequestResource GetResource();
}
In my NinjectDependencyResolver:
.....
kernel.Bind<IPerRequestResourceProvider>.To<PerRequestResourceProvider>().InRequestScope();
I inject IPerRequestResourceProvider in few classes. But when I add breakpoint to PerRequestResourceProvider constructor I see that PerRequestResourceProvider is created three times during one request and not single per request. What's wrong?
Update: source code ttps://bitbucket.org/maximtkachenko/ninjectinrequestscope/src
There are two issues with your code:
Ninject is not getting initialized correctly.
You need one of the Ninject.MVCx packages (according to the MVC version you are using). To configure it correctly, see: http://github.com/ninject/ninject.web.mvc
You are injecting PerRequestResourceProvider (the class type), and not IPerRequestResourceProvider (the interface type) into HomeController, thus the .InRequestScope() defined on the IPerRequestResourceProvider binding is not taking any effect. Change the HomeController constructor to get the inteface type injected and you're good.
Ninject does not require bindings for instantiatable (non-abstract,..) classes. This is why it is not obvious when the wrong binding is used.
I'm going crazy so I got this
public class FrameworkDbTestBase : IDisposable
{
protected readonly FrameworkDb Db;
public FrameworkDbTestBase()
{
var connection = Effort.DbConnectionFactory.CreateTransient();
Db = new FrameworkDb(connection);
}
public void Dispose()
{
Db.Dispose();
}
}
This is mocking the ef6 with effort .. love it so I can continuously perform tests in the background while all the changes are happening against my codebase ... its great but unfortunately I need to this
public partial class FrameworkDb : DbContext
{
public FrameworkDb() : base("DefaultConnection"){}
public FrameworkDb(DbConnection connection): base(connection, true)
{
Configuration.LazyLoadingEnabled = false;
}
public DbSet<Site> Sites { get; set; }
...
in order to get the mocking of ef6 with effort going however structuremap insists on creating me a FrameworkDb instance with the long constructor the one with the DbConnection injection parameter so I get this:
StructureMap.StructureMapException was unhandled by user code
HResult=-2146232832
Message=StructureMap Exception Code: 202
No Default Instance defined for PluginFamily System.Data.Common.DbConnection, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
Source=StructureMap
ErrorCode=202
Sigh! I roll my eyes up ... I want structuremap to use me the other shorter constructor so after some digging according to this post: Structure Map - I dont want to use the greediest constructor! I should change this:
For<FrameworkDb>().Use <FrameworkDb>();
to this
For<FrameworkDb>().Use(() => new FrameworkDb());
No such luck still same error ... and I dont want to remove the connection constructor else my integration test wont work anymore... So maybe it uses the connection only the construct the mapping and not actually use it in the injection itself ... no such luck ... adding this:
For<DbConnection>().Use(() => new EntityConnection("DefaultConnection"));
gives me that:
StructureMap.StructureMapException was unhandled by user code
HResult=-2146232832
Message=StructureMap Exception Code: 207
Internal exception while creating Instance '00fbcc4f-c5f0-4eb3-b814-9d0ba1bb8e19' of PluginType System.Data.Common.DbConnection, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089. Check the inner exception for more details.
Source=StructureMap
ErrorCode=207
Well so much for that theory... ahum... solution anyone? Hellooo anyone? Sigh ...
Come on people no one? The answer is so simple ... well
var framework = new Framework();
For<FrameworkDb>().Use(() => framework);
So simple yet so elegant and something you just have to know!
I have just started experimenting with Web Api 2 and StructureMap, having installed StructureMap.MVC4 Nuget package. Everything seems to work fine until I tried to register a user. I got this error when this implementation of IHttpControllerActivator tried to instantiate a controller:
public class ServiceActivator : IHttpControllerActivator
{
public ServiceActivator(HttpConfiguration configuration) { }
public IHttpController Create(HttpRequestMessage request
, HttpControllerDescriptor controllerDescriptor, Type controllerType)
{
var controller = ObjectFactory.GetInstance(controllerType) as IHttpController;
return controller;
}
}
The error I got was:
StructureMap Exception Code: 202
No Default Instance defined for PluginFamily Microsoft.AspNet.Identity.IUserStore`1[[Microsoft.AspNet.Identity.EntityFramework.IdentityUser, Microsoft.AspNet.Identity.EntityFramework, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]], Microsoft.AspNet.Identity.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35
I understand what the error is, but not entirely sure how to solve it. Is it correct to assume the default scanner in StructureMap could not find a default implementation of IUserStore? Here's the initialisation code I used:
ObjectFactory.Initialize(x => x.Scan(scan =>
{
scan.AssembliesFromApplicationBaseDirectory();
scan.WithDefaultConventions();
}));
Any ideas please? Thanks.
EDIT:
I think I may have solved the initial issue using this:
x.For<Microsoft.AspNet.Identity.IUserStore<IdentityUser>>()
.Use<UserStore<IdentityUser>>();
But now there's another default instance StructureMap couldn't work out - the dbcontext. Here's the next error message I'm getting:
ExceptionMessage=StructureMap Exception Code: 202
No Default Instance defined for PluginFamily System.Data.Entity.DbContext, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089
Now I'm really lost...
The WithDefaultConventions() call won't pick up your DbContext and AspNet Identity implementations. You'll want to look at some of the other methods like SingleImplementationsOfInterface() and ConnectImplementationsToTypesClosing.
By default when I setup my StructureMap container, I will do the following configuration in order to ensure that StructureMap will always resolve the interfaces and base classes of my preferred class to my actual preferred class:
ioc.For<MyDbContext>().HybridHttpOrThreadLocalScoped().Use<MyDbContext>();
ioc.For<DbContext>().HybridHttpOrThreadLocalScoped().Use<MyDbContext>();
For the new AspNet Identity classes, just subclass the generic classes they give you out of the box:
public class MyUserManager : UserManager<MyUser> { }
public class MyUserStore : UserStore<MyUser> { }
And then again, make sure StructureMap knows about these:
ioc.For<IUserStore<MyUser>>().Use<MyUserStore>();
ioc.For<UserStore<MyUser>>().Use<MyUserStore>();
ioc.For<UserManager<MyUser>>().Use<MyUserManager>();
Generally, you don't have to explicitly register every class with StructureMap, but with my DbContext and Identity classes, I prefer to have those explicity registered for maintenance purposes.
ericb: I can see the purpose of what you've posted but I can't quite get it to work. The MyUserManager class declaration "public class MyUserManager : UserManager { }" is complaining that the UserManager interface does not contain a constructor that takes 0 arguments?
Any help would be greatly appreciated!
Ps. This is by no means an answer but I'm not qualified enough to simply comment on your answer unfortunately!
Update: Found a solution here: Dependency Injection Structuremap ASP.NET Identity MVC 5
For clarity we replaced any of the above with the following in the IoC file:
x.For<Microsoft.AspNet.Identity.IUserStore<ApplicationUser>>()
.Use<Microsoft.AspNet.Identity.EntityFramework.UserStore<ApplicationUser>>();
x.For<System.Data.Entity.DbContext>().Use(() => new ApplicationDbContext());
I'm sure we're missing out on some extra benefits that ericb gets with his solution but we're not utilising anything that would take advantage of them.
There is a quick and easy workaround to this problem as well, and in many cases may be sufficient. Go to AccountController.cs and above the default constructor (the one with no params or code in it) add [DefaultConstructor] and resolve using structuremap.
[DefaultConstructor]
public AccountController()
{
}
Though the proper IoC solution is this...
For<IUserStore<ApplicationUser>>().Use<UserStore<ApplicationUser>>();
For<DbContext>().Use<ApplicationDbContext>(new ApplicationDbContext());
For<IAuthenticationManager>().Use(() => HttpContext.Current.GetOwinContext().Authentication);
Or you can try constructor injection method:
x.For<IUserStore<ApplicationUser>>().Use<UserStore<ApplicationUser>>()
.SelectConstructor(() => new UserStore<ApplicationUser>(new MyContext()));
I am using unity as my IoC container. I am trying to implement a type of IProviderRepository. The concrete implementation has a constructor that accepts a type of IRepository. When I remove the constructor parameter from the concrete implementation everything works fine. I am sure the container is wired correctly. When I try to create the concrete object with the constructor I receive the following error:
"The current build operation (build key Build Key[EMRGen.Infrastructure.Data.IRepository1[EMRGen.Model.Provider.Provider], null]) failed: The current type, EMRGen.Infrastructure.Data.IRepository1[EMRGen.Model.Provider.Provider], is an interface and cannot be constructed. Are you missing a type mapping? (Strategy type BuildPlanStrategy, index 3)".
Is it possible to achieve the above mention functionality with Unity? Namely have Unity infer a concrete type from the Interface and also inject the constructor of the concrete type with the appropriate concrete object based on constructor parameters. Below is sample of my types defined in Unity and a skeleton class listing for what I want to achieve. IProviderRepository is implemented by ProviderRepository which has a constructor that expects a type of IRepository.
<typeAlias alias="ProviderRepositoryInterface" type="EMRGen.Model.Provider.IProviderRepository, EMRGen.Model" />
<typeAlias alias="ProviderRepositoryConcrete" type="EMRGen.Infrastructure.Repositories.Providers.ProviderRepository, EMRGen.Infrastructure.Repositories" />
<typeAlias alias="ProviderGenericRepositoryInterface" type="EMRGen.Infrastructure.Data.IRepository`1[[EMRGen.Model.Provider.IProvider, EMRGen.Model]], EMRGen.Infrastructure" />
<typeAlias alias="ProviderGenericRepositoryConcrete" type="EMRGen.Infrastructure.Repositories.EntityFramework.ApplicationRepository`1[[EMRGen.Model.Provider.Provider, EMRGen.Model]], EMRGen.Infrastructure.Repositories" />
<!-- Provider Mapping-->
<typeAlias alias="ProviderInterface" type="EMRGen.Model.Provider.IProvider, EMRGen.Model" />
<typeAlias alias="ProviderConcrete" type="EMRGen.Model.Provider.Doctor, EMRGen.Model" />
Illustrate the call being made inside my class:
public class PrescriptionService
{
PrescriptionService()
{
IUnityContainer uc = UnitySingleton.Instance.Container;
UnityServiceLocator unityServiceLocator = new UnityServiceLocator(uc);
ServiceLocator.SetLocatorProvider(() => unityServiceLocator);
IProviderRepository pRepository =
ServiceLocator.Current.GetInstance<IProviderRepository>();
}
}
public class GenericRepository<IProvider> : IRepository<IProvider>
{
}
public class ProviderRepository : IProviderRepository
{
private IRepository<IProvider> _genericProviderRepository;
//Explict public default constructor
public ProviderRepository(IRepository<IProvider> genericProviderRepository)
{
_genericProviderRepository = genericProviderRepository;
}
}
What you want to do is possible, but you need to tell Unity how to map from interfaces to concrete types. AFAICT, your current configuration registers a lot of types, but doesn't specify how they relate to each other.
That said, static Service Locator is an anti-pattern. Consider changing your code to use proper Constructor Injection instead. That would also simplify your code considerably:
public class PrescriptionService
{
private readonly IProviderRepository pRepository;
public PrescriptionService(IProviderRepository pRepository)
{
if (pRepository == null)
{
throw new ArgumentNullException("pRepository");
}
this.pRepository = pRepository;
}
}
Using Unity, you would be able to wire it up like this:
var container = new UnityContainer();
container.RegisterType<PrescriptionService>();
container.RegisterType<IProviderRepository, ProviderRepository>();
container.RegisterType<IRepository<IProvider>, MyRepository<IProvider>>();
var ps = container.Resolve<PrescriptionService>();
Configure the container and resolve all components in the application's Composition Root.
You should only use XML configuration if you need to be able to change certain components without recompiling your application.