Is it possible to change the default object scope in Ninject 2.2? If so, how is it done?
As far as I can tell you could override AddBinding() on the BindingRoot (StandardKernel or NinjectModule) and modify the ScopeCallback property on the binding object.
public class CustomScopeKernel : StandardKernel
{
public CustomScopeKernel(params INinjectModule[] modules)
: base(modules)
{
}
public CustomScopeKernel(
INinjectSettings settings, params INinjectModule[] modules)
: base(settings, modules)
{
}
public override void AddBinding(IBinding binding)
{
// Set whatever scope you would like to have as the default.
binding.ScopeCallback = StandardScopeCallbacks.Singleton;
base.AddBinding(binding);
}
}
This test should now pass (using xUnit.net)
public class DefaultScopedService { }
[Fact]
public void Should_be_able_to_change_default_scope_by_overriding_add_binding()
{
var kernel = new CustomScopeKernel();
kernel.Bind<DefaultScopedService>().ToSelf();
var binding = kernel.GetBindings(typeof(DefaultScopedService)).First();
binding.ScopeCallback.ShouldBe(StandardScopeCallbacks.Singleton);
}
The CustomScopeKernel will also work with Ninject modules.
public class ServiceModule : NinjectModule
{
public override void Load()
{
Bind<DefaultScopedService>().ToSelf();
}
}
[Fact]
public void Should_be_able_to_change_default_scope_for_modules()
{
var module = new ServiceModule();
var kernel = new CustomScopeKernel(module);
var binding = kernel.GetBindings(typeof(DefaultScopedService)).First();
binding.ScopeCallback.ShouldBe(StandardScopeCallbacks.Singleton);
}
Related
I am getting the following error whenever I try to inject one of my service's dependency into the MVC controller:
Error activating IFeedService No matching bindings are available, and the type is not self-bindable.
Activation path:
2) Injection of dependency IFeedService into parameter svc of constructor of type FeedController
1) Request for FeedController
Suggestions:
1) Ensure that you have defined a binding for IFeedService.
2) If the binding was defined in a module, ensure that the module has been loaded into the kernel.
3) Ensure you have not accidentally created more than one kernel.
4) If you are using constructor arguments, ensure that the parameter name matches the constructors parameter name.
5) If you are using automatic module loading, ensure the search path and filters are correct.
======================================================================
Here's how my code looks like:
ObjectFactory.cs
private static void RegisterServices(IKernel kernel)
{
// Contexts
kernel.Bind<IEntityObjectContext>().To<Entities>();
kernel.Bind<IAzureObjectContext>().To<AzureTableObjectContext>();
// Repositories
kernel.Bind<IEFRepository>().To<EFRepository>();
kernel.Bind<IAzureRepository>().To<AzureRepository>();
// Services
kernel.Bind<IFeedService>().To<FeedService>();
}
IEFRepository.cs
public interface IEFRepository : IDisposable
{
void SetContext(IEntityObjectContext context);
IQueryable<T> GetAll<T>() where T : class;
}
EFRepository.cs
public class EFRepository : IEFRepository
{
internal IEntityObjectContext context;
private Dictionary<Type, object> objectSets;
public EFRepository(IEntityObjectContext context)
{
this.context = context;
objectSets = new Dictionary<Type, object>();
}
public void SetContext(IEntityObjectContext context)
{
this.context = context;
}
}
IFeedService.cs
public interface IFeedService : IDisposable
{
IQueryable<FeedItem> GetPosts();
}
FeedService.cs
public class FeedService : IFeedService
{
private IEntityObjectContext _context;
private readonly IEFRepository _repo;
public FeedService(IEntityObjectContext context,
IEFRepository repo)
{
_context = context;
_repo = repo;
_repo.SetContext(_context);
}
public IQueryable<FeedItem> GetPosts()
{
using (_repo)
{
return _repo.GetAll<FeedItem>().Take(10);
}
}
}
FeedController.cs
public class FeedController : Controller
{
private readonly IFeedService _svc;
public FeedController(IFeedService svc)
{
_svc = svc;
}
}
As you can see, there are some nested dependency there in action. Not sure though, what needs to be added/removed for this bit to work.
Note: The error is thrown whenever I request the Feed/FetchFeed path. I also tried to comment out the FeedService's constructor portion to see if the nested dependencies are creating any problem, but again same error was thrown.
EDIT 1:
Rest of the code for the ObjectFactory.cs
class ObjectFactory
{
static ObjectFactory()
{
RegisterServices(kernel);
}
static IKernel kernel = new StandardKernel();
public static T GetInstance<T>()
{
return kernel.Get<T>();
}
private static void RegisterServices(IKernel kernel)
{
//...
}
}
EDIT 2:
I even tried to write a fairly basic service, but still the same error. Here's what I tried with:
public interface ITest
{
void CheckItOut();
}
public class Test : ITest
{
public void CheckItOut()
{
}
}
ObjectFactory.cs
kernel.Bind<ITest>().To<Test>();
AutoMapper Version Used : 3.3.10
[TestClass]
public class AppControllerTests
{
private IMappingEngine _mappingEngine = null;
private ConfigurationStore _configurationStore = null;
[TestInitialize]
public void SetUp()
{
_configurationStore = new ConfigurationStore(new TypeMapFactory(), MapperRegistry.Mappers);
_configurationStore.AddProfile(new AutoMapperProfile.AppProfile());
_mappingEngine = new MappingEngine(_configurationStore);
}
[TestMethod]
public void GetAppByAccountID()
{
// Error line
var mappingResult = _mappingEngine.Map<Category>(categoryList).AsQueryable();
}
}
public class AppProfile : Profile
{
protected override void Configure()
{
AutoMapperMappingConfigurations();
}
public void AutoMapperMappingConfigurations()
{
Mapper.CreateMap<DomainModels.Category, Category>().ReverseMap();
}
}
Exception:
An exception of type 'AutoMapper.AutoMapperMappingException'
occurred in AutoMapper.dll but was not handled in user code.
Suspect the
_configurationStore.AddProfile(new OOS.PresentationModelService.AutoMapperProfile.AppProfile());
is not able to create an istance of AppProfile if i write the manual mapping it's working as expected.
_configurationStore.CreateMap<Category, Category>().ReverseMap();
I want to inject unity container into WebController.
I have UnityDependencyResolver:
public class UnityDependencyResolver : IDependencyResolver
{
readonly IUnityContainer _container;
public UnityDependencyResolver(IUnityContainer container)
{
this._container = container;
}
public object GetService(Type serviceType)
{
try
{
return _container.Resolve(serviceType);
}
catch
{
return null;
}
}
public IEnumerable<object> GetServices(Type serviceType)
{
try
{
return _container.ResolveAll(serviceType);
}
catch
{
return new List<object>();
}
}
public void Dispose()
{
_container.Dispose();
}
}
Then, in my Global.asax I add the following line:
var container = new UnityContainer();
container.RegisterType<IService, Service>
(new PerThreadLifetimeManager()).RegisterType<IDALContext, DALContext>();
DependencyResolver.SetResolver(new UnityDependencyResolver(container));
Then, If I use the following in a Web Controller:
private IService _service;
public HomeController(IService srv)
{
_service = srv;
}
It works fine.
But I want to inject it into WebAPI Controller, so if I do it the same way:
private IService _service;
public ValuesController(IService srv)
{
_service = srv;
}
It does not work, it says that constructor is not defined.
Ok, I create one more constructor:
public ValuesController(){}
And in this case it uses only this constructor and never the one where I should inject unity container.
Please advise.
Add this in your WebApiConfig:
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
// Routes and other stuff here...
var container = IocContainer.Instance; // Or any other way to fetch your container.
config.DependencyResolver = new UnityDependencyResolver(container);
}
}
And if you want the same container you can keep it in a static variable, like so:
public static class IocContainer
{
private static readonly Lazy<IUnityContainer> Container = new Lazy<IUnityContainer>(() =>
{
var container = new UnityContainer();
return container;
});
public static IUnityContainer Instance
{
get { return Container.Value; }
}
}
More info can be found here:
http://www.asp.net/web-api/overview/advanced/dependency-injection
On a sidenote, I can also recommend the nuget-package Unity.Mvc. It adds a UnityWebActivator and support for PerRequestLifetimeManager.
https://www.nuget.org/packages/Unity.Mvc/
Let's say I would like to inject an implementation of this interface:
interface IService { ... }
implemented as:
class MyService : IService
{
public MyService(string s) { }
}
in an instance of this class:
class Target
{
[Inject]
public IService { private get; set; }
}
I do the injection by calling kernel.Inject(new Target()), but what if I would like to specify the parameter s of the constructor depending on some context when calling Inject?
Is there a way to achieve such context-dependant service initialization at injection?
Thanks!
In most cases you should not use Field Injection, it should be
used only in rare cases of circular dependencies.
You should only use the kernel once at the start of your
application and never again.
Example Code:
interface IService { ... }
class Service : IService
{
public Service(string s) { ... }
}
interface ITarget { ... }
class Target : ITarget
{
private IService _service;
public Target(IServiceFactory serviceFactory, string s)
{
_service = serviceFactory.Create(s);
}
}
interface ITargetFactory
{
ITarget Create(string s);
}
interface IServiceFactory
{
IService Create(string s);
}
class NinjectBindModule : NinjectModule
{
public NinjectBindModule()
{
Bind<ITarget>().To<Target>();
Bind<IService>().To<Service>();
Bind<ITargetFactory>().ToFactory().InSingletonScope();
Bind<IServiceFactory>().ToFactory().InSingletonScope();
}
}
Usage:
public class Program
{
public static void Main(string[] args)
{
IKernel kernel = new StandardKernel(new NinjectBindModule());
var targetFactory = kernel.Get<ITargetFactory>();
var target = targetFactory.Create("myString");
target.DoStuff();
}
}
Simply done using parameters...
kernel.Inject(new Target(), new ConstructorArgument("s", "someString", true));
Does anyone have an implementation lying around of an auto-mock container using Rhino Mocks and NInject?
OK I built one myself using the Moq integration as a starting point. It is very simple. You need these 3 classes:
public class AutoMockingKernel : StandardKernel
{
private readonly IMockProvider _mockProvider;
public void Reset()
{
Components.Get<ICache>().Clear();
}
protected override bool HandleMissingBinding(Type service)
{
var isSelfBindable = TypeIsSelfBindable(service);
var binding = new Binding(service)
{
ProviderCallback = isSelfBindable
? StandardProvider.GetCreationCallback(service)
: _mockProvider.GetCreationCallback(),
IsImplicit = true
};
if (!isSelfBindable)
binding.ScopeCallback = ctx => null;
AddBinding(binding);
return true;
}
public AutoMockingKernel(IMockProvider mockProvider, INinjectSettings settings, params INinjectModule[] modules)
: base(settings, modules)
{
_mockProvider = mockProvider;
}
public AutoMockingKernel(IMockProvider mockProvider, params INinjectModule[] modules)
: base(modules)
{
_mockProvider = mockProvider;
}
}
internal class RhinoMockProvider : IProvider
{
public Type Type { get; private set; }
/// <summary>
/// Initializes a new instance of the <see cref="RhinoMockProvider"/> class.
/// </summary>
public RhinoMockProvider(Type type)
{
Type = type;
}
public object Create(IContext context)
{
return MockRepository.GenerateMock(Type, Type.EmptyTypes);
}
}
public class RhinoAutoMockProvider : IMockProvider
{
public Func<IContext, IProvider> GetCreationCallback()
{
return ctx => new RhinoMockProvider(ctx.Request.Service);
}
}
You can then create an auto-mocking kernel in your unit test like this:
[Test]
public void Test()
{
var kernel = new AutoMockingKernel(new RhinoAutoMockProvider());
... etc
}
There is a RhinoMocks integration extension available.