I have a repository like this:
public class Repository<T> : IRepository<T> where T : class
{
private readonly ISession session;
public Repository(ISession session)
{
this.session = session;
}
}
I use NHQS and I usually do this to get a ISession object:
SessionFactory.For<T>().OpenSession();
How do I setup Ninject to create a session automatically for the requested type and bind it? I tried this but I don't know what to put in the For<>():
kernel.Bind(typeof(IRepository<>))
.To(typeof(Repository<>))
.WithConstructorArgument("session", SessionFactory.For<>().OpenSession());
Looks like I need to get the generic type being used and pass it in the For<>()
How do I do that?
You should'nt use WithConstructorArgument; create a binding for ISession instead.
kernel.Bind<ISession>.ToMethod(context => ....).InRequestScope();
You can get the IRepository<> type from context.Request.ParentRequest.Service. You can now extract the entity type using reflection. However, if you are using the same database for all entities then it is probably easier to return a general session for all repositories.
Related
I have an Interface that will take in a generic type T
internal interface IQuestion<T> where T : IWithOptionsId
{
Task<T> Provide(Guid id);
}
Following by that I will implement this interface in multiple classes. For example
public class SomeProvider : IQuestion<OptionsClass>
{
private readonly IRepository _repository;
public SomeProvider(IRepository repository)
{
_repository = repository;
}
public async Task<OptionsClass> Provide(Guid id)
...
}
To register this with outofac I used this
Autofac.RegisterAssemblyTypes(
Assembly.GetExecutingAssembly())
.AsImplementedInterfaces()
.AsClosedTypesOf(typeof(IQuestion<>));
My question is this. I have multiple instances for this interface. How do I access different instance once at the run time? If my IQuestion<T> will take in Options class and also it will take in Answer class how can I get an instance of those classes during run time?
I'm pretty sure you can just inject the instance itself. Not great practice, but it should work:
public SomeClass(SomeProvider<OptionsClass> provider)
You could also try creating a named instance when you register it, and inject that. See this and this.
I've an abstract class:
[Configuration]
public abstract class AbstractAddon : IAddon
{
private readonly object configuration;
public AbstractAddon(object configuration)
{
this.configuration = configuration;
}
}
And several implementation of this.
I create a binding by convention as:
public class AddonsModule : Ninject.Modules.NinjectModule
{
public override void Load()
{
this.Bind(b => b.FromAssembliesMatching("*")
.SelectAllClasses()
.InheritedFrom(typeof(UIExtensibility.AbstractAddon))
.BindAllBaseClasses()
.Configure(c => c.InSingletonScope())
);
this.Bind<object>().ToProvider<ConfigurationProvider>().WhenClassHas<UIExtensibility.ConfigurationAttribute>();
}
and ConfigurationProvider is:
private class ConfigurationProvider : IProvider<object>
{
public object Create(IContext context)
{
return "configuration settings";
}
//...
}
Inside the Create method of ConfigurationProvider I thought I might be allowed to access which is the concrete class which is being requested around.
Each concrete class have an attribute PluginInformation I need in order to provide the correct configuration object. However, I don't know how to know which is the concrete class NInject is creating at the moment of the Create method provider is performed. And then, I can't get the PluginInformation attribute I need to link it and provide the correct configuration object.
How could I get access to the concrete class NInject is requesting at the moment of the object provider is performed?
The trouble was that on the first level of the IContext context parameter information, there is only the information according the Type it's providing, in my case: object type.
However IContext comes with the complete parent and plan context. So, at the point of the Create method of the provider is performed, some braches of the resolution are solved, for example: AbstractAddon. Every resolved information is on 'Context' like IContext fields. Moreover, the future steps are on 'Plan' like IContext fields.
So, in order to get the concrete type (inherited classes of AbstractAddon), I need to read the next property: context.Request.ParentContext.Plan.Type.
I have a repository offering a GetAll method which again calls the Query extension method on the ISession instance of NHibernate.
public ICollection<Product> GetAll()
{
return _session.Query<Product>().ToList();
}
My unit test looks like this:
[Test]
public void GetAllReturnsCollectionFromSession()
{
IQueryable<Product> productList = new ProductListBuilder().Build().AsQueryable();
_fixture.Session.Query<Product>().Returns(productList);
var sut = _fixture.CreateSut();
var result = sut.GetAll();
Assert.AreSame(productList, result);
_fixture.Session.Received().Query<Product>();
}
In the _fixture.Session.Query().Returns(productList) statement, NSubstitute throws the following exception:
NSubstitute.Exceptions.CouldNotSetReturnDueToTypeMismatchException : Can not return value of type IQueryable`1Proxy for ISession.GetSessionImplementation (expected type ISessionImplementor).
Make sure you called Returns() after calling your substitute (for example: mySub.SomeMethod().Returns(value)),
and that you are not configuring other substitutes within Returns() (for example, avoid this: mySub.SomeMethod().Returns(ConfigOtherSub())).
If you substituted for a class rather than an interface, check that the call to your substitute was on a virtual/abstract member.
Return values cannot be configured for non-virtual/non-abstract members.
Correct use:
mySub.SomeMethod().Returns(returnValue);
Potentially problematic use:
mySub.SomeMethod().Returns(ConfigOtherSub());
Instead try:
var returnValue = ConfigOtherSub();
mySub.SomeMethod().Returns(returnValue);
at NSubstitute.Core.ConfigureCall.CheckResultIsCompatibleWithCall(IReturn valueToReturn, ICallSpecification spec)
at NSubstitute.Core.ConfigureCall.SetResultForLastCall(IReturn valueToReturn, MatchArgs matchArgs)
at NSubstitute.Core.CallRouter.LastCallShouldReturn(IReturn returnValue, MatchArgs matchArgs)
at NSubstitute.Core.SubstitutionContext.LastCallShouldReturn(IReturn value, MatchArgs matchArgs)
at NSubstitute.SubstituteExtensions.Returns[T](MatchArgs matchArgs, T returnThis, T[] returnThese)
at NSubstitute.SubstituteExtensions.ReturnsForAnyArgs[T](T value, T returnThis, T[] returnThese)
at Statoil.Wellcom.DataLayer.Implementation.Oracle.UnitTests.Repositories.DwapplicationRepositoryTests.GetAllReturnsCollectionFromSession() in C:\git\WELLCOM\source\Statoil.Wellcom.DataLayer.Implementation.Oracle.UnitTests\Repositories\DwapplicationRepositoryTests.cs:line 123
It looks like NSubstitute is unable to set the return value due to Query being an extension method. How would I go about mocking the extension method call on the ISession?
The easiest solution is to wrap your ISession in another interface/concrete class so you can stub that out:
public interface ISessionWrapper
{
IQueryable<T> Query<T>();
}
public class SessionWrapper : ISessionWrapper
{
private readonly ISession _session;
public SessionWrapper(ISession session)
{
_session = session;
}
public IQueryable<T> Query<T>()
{
return _session.Query<T>();
}
}
There is no way to mock extension method with NSubstitute, however if you know what extension method is using inside, than you can mock that. Your test will use extension method on mocked object and eventually it will use mocked method. Difficult part is to know what is going on inside.
It worked for me in projects, where I knew all the source code and I could check what's inside.
I am getting this error when I try to use code first migrations.
My context has a constructor with the connection name.
public class VeraContext : DbContext, IDbContext
{
public VeraContext(string NameOrConnectionStringName = "VeraDB")
: base(NameOrConnectionStringName)
{
}
public IDbSet<User> Users { get; set; }
public IDbSet<Product> Products { get; set; }
public IDbSet<IntCat> IntCats { get; set; }
}
This connection name is injected with ninject when the project runs, I have also specified it as a default as in the above code but this did not help.
kernel.Bind<IDbContext>()
.To<VeraContext>()
.WithConstructorArgument("NameOrConnectionStringName", "VeraDB");
When I try to add migrations with "Enable-Migrations" is throws up the error:
The target context 'VeraData.EF.Infrastructure.VeraContext' is not
constructible. Add a default constructor or provide an implementation
of IDbContextFactory.
If I remove the constructor from VeraContext it will work but creates another database with VeraData.EF.Infrastructure.VeraContext as its name.
I presume that ninject only passes the connection string when the project runs and not when I use code first migrations. Anyway I can inject/provide a default for the connection name when using code first migrations ?
Essentially you need a default ctor (that's the error) - but just implementing it would lead to problems.
You'd have to implement the IDbContextFactory for the results to be consistent (or your migration from code won't work etc.).
Migrations actually call your default constructor to make a
connection. So you're other ctor won't matter much.
Here is the basic factory...
public class MyContextFactory : IDbContextFactory<MyContext>
{
public MyContext Create()
{
return new MyDBContext("YourConnectionName");
}
}
You should combine that with injection, to inject and construct your DbContext as you wish.
If you don't want to spend time looking into the IDbContextFactory option, and to get things working create a default constructor and hard-code the name of the connection string when calling the base DbContext:
public class CustomContext : DbContext
{
public CustomContext() :base("name=Entities") {}
}
SRC: http://www.appetere.com/Blogs/SteveM/April-2012/Entity-Framework-Code-First-Migrations
To complement #nccsbim071 answer, I have to add one more thing... this option doesn't like constructor with default parameters... for instance:
public MyContext(bool paramABC = false) : base("name=Entities") {...}
instead you have to create a non-parameter (default) constructor and the parameter-constructor like old fashion way.
public MyContext() :base("name=Entities") {...}
public MyContext(bool paramABC) : this() {...}
NOTE:
Entities in this case means the connection string name... By convention, the name of the context is the same as the connection string name and since MyContext is not the same as Entities, it's necessary specify it manually.
In my situation I wanted to use the default connection factory, instead of explicitly providing one. Somewhere inside EF6 it'll try to lookup the factory, but it fails with this exception message. Stepping through the EF6 code, I found that Glimpse.Ado was wrapping the connection factory, which made the lookup fail to find a match.
here is my problem: I'm building a desktop application, with the following tools:
Caliburn
Ninject
NHibernate
All my view models and repositories are instanciated with Ninject. My repositories all need an ISession in their constructor.
I'd like to follow ayende's advice concerning the ViewModels: each ViewModel opens a new session.
Is it possible to configure Ninject to open a new session when a ViewModel is created, and use this session inside the repositories used by this view model?
I had a look to the InScope function of Ninject, as well as the ICurrentSessionContext interface in NHibernate, but I don't know how to model all of that to get what I want...
Did someone make something like that before?
Thanks in advance
Mike
I solved a similar scenario leveraging the ViewModel lifecycle: I created an ISessionAware interface (with a SetSession method) to be implemented by repositories, then I initialized the repositories through ISessionAware in the OnInitialize method of the ViewModel (which is enforced by Caliburn when the VM is managed by a ScreenConductor).
Using reflection to inspect the properties holding the repositories, I could put all the infrastructure on a BaseDataVM class.
Using a scope in the container would be more elegant, I think, but I don't know Ninject.
I have a very similar project (except I'm not using Caliburn) and have been trying to figure out how to do this as well. I did come up with one method that works well for constructor injection using Ninject's InScope() method.
I have a static class called IoC that wraps access to Ninject's kernel. Since the dependencies are all injected into the constructor, the context is only relevant when the object is being created. So it doesn't matter what is supplied for context, but a Guid feels like the safe choice. Program.OpenSession() is a static method to open a new ISession.
public static class Ioc
{
private static readonly IKernel _kernel;
static IoC()
{
_kernel = new StandardKernel();
_kernel.Load(new ContextModule());
}
private static object _context;
public static T ResolveInContext<T>(object context)
{
_context = context;
var result = _kernel.Get<T>();
_context = null;
return result;
}
private class ContextModule : NinjectModule
{
public override void Load()
{
Bind<ISession>().ToMethod(x => Program.OpenSession()).InScope(x => _context);
Bind<frmCompanyViewer>().ToSelf().InScope(x => _context);
}
}
}
Usage is:
var frm = IoC.ResolveInContext<frmCompanyViewer>(Guid.NewGuid());
The form's constructor signature is:
public frmCompanyViewer(ISession session, ICompanyRepository companyRepository)
I verified that with InScope on the bindings, the same ISession that is used to construct frmCompanyViewer is also used to construct companyRepository. If I remove InScope then two ISessions are used.
Edited to add: This would also work, see comments. This should be made thread safe for a real application. I changed the method name to ConstructInContext to clarify that the context only applies during object construction.
public static T ConstructInContext<T>()
{
_context = Guid.NewGuid();
var result = _kernel.Get<T>();
_context = null;
return result;
}
We have this with AOP, in unhaddins.
Is called "Conversation per Business Transaction".
search in google
here you have ;)
http://groups.google.com/group/unhaddins/browse_thread/thread/29eca74a83df5faf/d9fab4062d4cb4c4?lnk=gst&q=ninject#d9fab4062d4cb4c4
Well, I've found a solution thanks to the ninject group.
The solution here is to use the function InScope when I bind ISession, and browse in the IContext variable to inspect the services. If one service in the request hierarchy is assignable to the base class of my view models, I use the context as scope.
So the first time an ISession will be injected in the constructor of my ViewModel, a new scope is used. And all subsequent calls to ISession inside the constructor of the ViewModel will be resolved with the same scope. And then only one session is created for my ViewModel.
Here is the code:
Bind<ISession>().ToMethod(ctx =>
{
var session = ctx.Kernel.Get<INHibernateSessionFactoryBuilder>()
.GetSessionFactory()
.OpenSession();
session.FlushMode = FlushMode.Commit;
return session;
})
.InScope(ctx =>
{
var request = ctx.Request;
if (request.Service is IScreen)
return request;
while ((request = request.ParentRequest) != null)
if (typeof(IScreen).IsAssignableFrom(request.Service))
return request;
return new object();
});
And the constructor of the viewmodel must contains all the injected dependencies which rely on the ISession:
[Inject]
public PlayersManagementViewModel(ISession session, IPlayersRepository playersRepository)
{
}
Hope that helps