Injecting Subsonic SimpleRepository class to controller - inversion-of-control

I'm tryingot get started with IoC, I have an MVC project in which is use subsonic, I'm trying to inject subsonic simplerepository to my controllers but I'm getting this error:
StructureMap Exception Code: 205
Missing requested Instance property "connectionStringName" for InstanceKey "60b735fb-0a7f-4eb4-be04-635f6f32233d"
Here is my registry class:
public class RepositoryRegistry : Registry
{
protected override void configure()
{
ForRequestedType<IRepository>().TheDefault.Is.OfConcreteType(typeof(SimpleRepository));
}
}
And here is my controller factory:
public class StoreControllerFactory: DefaultControllerFactory
{
protected override IController GetControllerInstance(Type controllerType)
{
IController result = null;
if (controllerType!=null)
{
result = ObjectFactory.GetInstance(controllerType) as Controller;
}
return result;
}
}
And this is how I configure StructureMap:
protected void Application_Start()
{
RegisterRoutes(RouteTable.Routes);
ObjectFactory.Initialize(x=>
{
x.AddRegistry(new RepositoryRegistry());
});
ControllerBuilder.Current.SetControllerFactory(new StoreControllerFactory());
var sparkSettings = new SparkSettings().SetDebug(true).AddNamespace("System.Web.Mvc.Html");
ViewEngines.Engines.Clear();
ViewEngines.Engines.Add(new SparkViewFactory(sparkSettings));
}
Any help would be appreciated! Thanks!

The problem is that StructureMap was using the constructor with the most parameters, I fixed with this:
ObjectFactory.Configure(
x => { x.SelectConstructor<SimpleRepository>(() => new SimpleRepository()); });

Related

Cannot resolve parameter 'MediatR.ServiceFactory serviceFactory' (MediatR with Autofac)

I'm attempting to run MediatR with Autofac in .NET Framework 4.6.2.
My registration:
public class MediatorModule : Autofac.Module
{
protected override void Load(ContainerBuilder builder)
{
builder.RegisterSource(new ContravariantRegistrationSource());
builder.RegisterAssemblyTypes(typeof(IMediator ).Assembly).AsImplementedInterfaces();
builder.RegisterType<HealthCheckQueryHandler>().As<IRequestHandler<HealthCheckQuery, HttpStatusCode>>();
}
}
My controller:
[RoutePrefix("api/v1/healthcheck")]
public class HealthCheckController : ApiController
{
private readonly IMediator _mediator;
public HealthCheckController(IMediator mediator)
{
_mediator = mediator;
}
[HttpGet]
[Route("")]
public async Task<HttpStatusCode> Get()
{
var query = new HealthCheckQuery();
var result = await _mediator.Send(query);
return result;
}
}
When I try to hit this api method, I receive the following error:
None of the constructors found with 'Autofac.Core.Activators.Reflection.DefaultConstructorFinder' on type 'MediatR.Mediator' can be invoked with the available services and parameters:\r\nCannot resolve parameter 'MediatR.ServiceFactory serviceFactory' of constructor 'Void .ctor(MediatR.ServiceFactory)
The wiki (https://github.com/jbogard/MediatR/wiki) asks us to register SingleInstanceFactory and MultiInstanceFactory. But Visual Studio is not able to resolve either of these symbols.
How can I resolve this to get MediatR working with Autofac?
I know this is an old post, but in case anyone else googles for this.
You're missing registering the ServiceFactory instance.
builder.Register<ServiceFactory>(ctx =>
{
var c = ctx.Resolve<IComponentContext>();
return t => c.Resolve(t);
});
Taken from here: MediatR Examples
I assume you are using Mediatr v3.0.x.
You are missing the registrations for the SingleInstanceFactory and MultiInstanceFactory as here below.
builder.Register<SingleInstanceFactory>(ctx => {
IComponentContext c = ctx.Resolve<IComponentContext>();
return type => {
Object o;
return c.TryResolve(type, out o) ? o : null;
};
});
builder.Register<MultiInstanceFactory>(ctx => {
IComponentContext c = ctx.Resolve<IComponentContext>();
return type => (IEnumerable<Object>)c.Resolve(typeof(IEnumerable<>).MakeGenericType(type));
});

Why am I getting error: "Cannot access disposed object" in .net core 2 with EF and AutoFac?

First the error:
Cannot access a disposed object. A common cause of this error is disposing a context that was resolved from dependency injection and
then later trying to use the same context instance elsewhere in your
application. This may occur if you are calling Dispose() on the
context, or wrapping the context in a using statement. If you are
using dependency injection, you should let the dependency injection
container take care of disposing context instances.
Object name: 'MemberContext'.
I have 3 projects, Domain, API and WebSPA app.
Domain has 2 modules, DomainModule and MediatorModule
public class DomainModule : Autofac.Module
{
protected override void Load(ContainerBuilder builder)
{
builder.RegisterAssemblyTypes(typeof(MemberContext).Assembly)
.AsImplementedInterfaces()
.InstancePerLifetimeScope(); // via assembly scan
builder.RegisterType<MemberContext>().AsSelf()
.InstancePerLifetimeScope(); // or individually
}
}
public class MediatorModule : Autofac.Module
{
protected override void Load(ContainerBuilder builder)
{
// enables contravariant Resolve() for interfaces with single contravariant ("in") arg
builder
.RegisterSource(new ContravariantRegistrationSource());
// mediator itself
builder
.RegisterType<Mediator>()
.As<IMediator>()
.InstancePerLifetimeScope();
// request handlers
builder
.Register<SingleInstanceFactory>(ctx =>
{
var c = ctx.Resolve<IComponentContext>();
return t =>
{
object o;
return c.TryResolve(t, out o) ? o : null;
};
})
.InstancePerLifetimeScope();
// notification handlers
builder
.Register<MultiInstanceFactory>(ctx =>
{
var c = ctx.Resolve<IComponentContext>();
return t => (IEnumerable<object>) c.Resolve(typeof(IEnumerable<>).MakeGenericType(t));
})
.InstancePerLifetimeScope();
}
}
In API project I have also 2 modules, ApplicationModule and again MediatorModule same as the one above.
public class ApplicationModule : Module
{
protected override void Load(ContainerBuilder builder)
{
builder.RegisterAssemblyTypes(typeof(Startup).Assembly)
.AsImplementedInterfaces()
.InstancePerLifetimeScope(); // via assembly scan
builder.RegisterType<MemberContext>().AsSelf().InstancePerLifetimeScope(); // or individually
}
}
No, when I debug I can see that member context gets newed up on each request, yet on second request, it throws above error. To make sure I am not going crazy, I modified constructor of dbcontext to create an id for context so i can verify they are different. What am I doing wrong?
public MemberContext(DbContextOptions<MemberContext> options) : base(options)
{
MemberContextId = Guid.NewGuid();
Console.WriteLine("member context created: " + MemberContextId);
}
Here is the startup in API
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public IServiceProvider ConfigureServices(IServiceCollection services)
{
services.AddCors(options =>
{
options.AddPolicy("CorsPolicy",
builder => builder.AllowAnyOrigin()
.AllowAnyMethod()
.AllowAnyHeader()
// .AllowCredentials()
);
});
services.AddMvc()
.AddControllersAsServices();//Injecting Controllers themselves thru DI
//For further info see: http://docs.autofac.org/en/latest/integration/aspnetcore.html#controllers-as-services
AddSwaggerGen(services);
//var connection = Configuration["ConnectionString"];
//services.AddDbContext<MemberContext>(options => options.UseSqlServer(connection),ServiceLifetime.Scoped);
services.AddEntityFrameworkSqlServer()
.AddDbContext<MemberContext>(options =>
{
options.UseSqlServer(Configuration["ConnectionString"]
//,sqlServerOptionsAction: sqlOptions =>
//{
// sqlOptions.MigrationsAssembly(typeof(Startup).GetTypeInfo().Assembly.GetName().Name);
// sqlOptions.EnableRetryOnFailure(maxRetryCount: 10, maxRetryDelay: TimeSpan.FromSeconds(30), errorNumbersToAdd: null);
//}
);
},
ServiceLifetime.Scoped //Showing explicitly that the DbContext is shared across the HTTP request scope (graph of objects started in the HTTP request)
);
var container = new ContainerBuilder();
container.Populate(services);
container.RegisterAssemblyModules(typeof(VIN.Members.Domain.Entities.Member).Assembly,
typeof(Startup).Assembly);
return new AutofacServiceProvider(container.Build());
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
//NOTE: must be before UseMVC !!!
app.UseCors("CorsPolicy");
app.UseMvc();
app.UseSwagger();
app.UseSwaggerUI(c =>
{
c.SwaggerEndpoint("/swagger/v1/swagger.json", "My API V1");
});
}
private void AddSwaggerGen(IServiceCollection services)
{
services.AddSwaggerGen(options =>
{
options.DescribeAllEnumsAsStrings();
options.SwaggerDoc("v1", new Swashbuckle.AspNetCore.Swagger.Info
{
Title = "VIN Members HTTP API",
Version = "v1",
Description = "Members Service HTTP API",
TermsOfService = "Terms Of Service"
});
});
}
}
UPDATE:
What I am trying to do is delete a record. On client side code looks like this
onDelete(item: IMember) {
//TODO: replace this with dialog service component
if (window.confirm('Are sure you want to delete this member?')) {
//put your delete method logic here
this.service.deleteMember(item).subscribe(x => {
this.getMembers();
});
}
}
this delete request gets mapped to a controller that passes it to mediator
Controller
// DELETE api/members/5
[HttpDelete("{id}")]
public void Delete(Guid id)
{
var command = new DeleteMember.Command(id);
_mediator.Send(command).ConfigureAwait(false);
}
and finally handler
public class DeleteMember
{
public class Command : IRequest
{
public Command(Guid memberId)
{
Guard.NotNull(memberId, nameof(memberId));
MemberId = memberId;
}
public Guid MemberId { get; }
}
public class Handler : AsyncRequestHandler<Command>
{
private MemberContext _context;
public Handler(MemberContext context)
{
_context = context;
Console.WriteLine("Delete member context: " + context.MemberContextId);
}
protected override async Task HandleCore(Command cmd)
{
try
{
var member = await _context.FindAsync<Member>(cmd.MemberId);//.ConfigureAwait(false);
// if (member != null)
//// {
_context.Remove(member);
await _context.SaveChangesAsync().ConfigureAwait(false);
// }
}
catch (Exception e)
{
Console.WriteLine(e);
throw;
}
}
}
}
As you can see there is no code that disposes that context. Scratching my head.
See this commented out check for member if null. That was throwing error as well, I commented it out just to see what will happen, and now it throws as SaveChangesAsync.
As request completes, context gets disposed. Since command handler uses SaveChangesAsync(), context is disposed before save completes. Culprit is controller method :). It should be async as well.
[HttpDelete("{id}")]
public async Task Delete(Guid id)
{
var command = new DeleteMember.Command(id);
await _mediator.Send(command).ConfigureAwait(false);
}
Your DbContext is scoped, meaning that Dependency Injection will return the same DbContext object every time one is asked for within the same HTTP request (in the case of ASP.NET).
That means that you should not be calling Dispose on your DbContext (otherwise that same object can't be used a second time). That seems to be what is happening to you, intentionally or not.
That does mean you should not be using using with it. Are you using using anywhere in your code against your DbContext?
I don't think you showed the line where the Exception is being thrown.
Update:
Try overriding Dispose in your MemberContext class. Something like this:
public override void Dispose() {
base.Dispose();
}
But just set a breakpoint there. When it breaks (if it does) check the stack trace and see what called it.
This can also be caused by having async void instead of async Task within WebAPI in my experience.

Testing code in a custom NancyFx Bootstrapper

I have a custom Nancy Bootstrapper which uses StructureMapNancyBootstrapper but the issue is the same regardless of container.
public class CustomNancyBootstrapper : StructureMapNancyBootstrapper
{
protected override void RequestStartup(IContainer container, IPipelines pipelines, NancyContext context)
{
var auth = container.GetInstance<ICustomAuth>();
auth.Authenticate(context);
}
}
I want to write a test to assert that Authenticate is called with the context... something like this...
[Test]
public void RequestStartup_Calls_CustomAuth_Authenticate_WithContext()
{
// set up
var mockAuthentication = new Mock<ICustomAuth>();
var mockContainer = new Mock<IContainer>();
var mockPipelines = new Mock<IPipelines>();
var context = new NancyContext();
mockContainer.Setup(x => x.GetInstance<ICustomAuth>()).Returns(mockAuthentication.Object);
// exercise
_bootstrapper.RequestStartup(_mockContainer.Object, _mockPipelines.Object, context);
// verify
mockAuthentication.Verify(x => x.Authenticate(context), Times.Once);
}
The problem is that I can't call RequestStartup because it's protected as defined in NancyBootstrapperBase.
protected virtual void RequestStartup(TContainer container, IPipelines pipelines, NancyContext context);
Is there a "proper"/"offical" Nancy way to do this without creating another derived class and exposing the methods as that just seems like a hack?
Thanks
I guess you can "fake" the request by using Browser from Nancy.Testing:
var browser = new Browser(new CustomNancyBootstrapper());
var response = browser.Get("/whatever");
There is a good set of articles about testing NancyFx application:
http://www.marcusoft.net/2013/01/NancyTesting1.html
Turns out Nancy offers a IRequetStartup interface so you can take the code out of the custom bootstrapper and do something like this...
public class MyRequestStart : IRequestStartup
{
private readonly ICustomAuth _customAuthentication;
public MyRequestStart(ICustomAuth customAuthentication)
{
if (customAuthentication == null)
{
throw new ArgumentNullException(nameof(customAuthentication));
}
_customAuthentication = customAuthentication;
}
public void Initialize(IPipelines pipelines, NancyContext context)
{
_customAuthentication.Authenticate(context);
}
}
and the test is easy and concise
[Test]
public void When_Initialize_Calls_CustomAuth_Authenticate_WithContext()
{
// set up
var mockAuth = new Mock<ICustomAuth>();
var requestStartup = new MyRequestStart(mockAuth.Object);
var mockPipeline = new Mock<IPipelines>();
var context = new NancyContext();
// exercise
requestStartup.Initialize(mockPipeline.Object, context);
// verify
mockAuth.Verify(x => x.Authenticate(context), Times.Once);
}
https://github.com/NancyFx/Nancy/wiki/The-Application-Before%2C-After-and-OnError-pipelines#implementing-interfaces

MVC source code singleton pattern

Why does .net MVC source code ControllerBuilder use a delegate to assign the controller factory?:
private Func<IControllerFactory> _factoryThunk;
public void SetControllerFactory(IControllerFactory controllerFactory) {
_factoryThunk = () => controllerFactory;
}
Why can't it just assign the ControllerFactory directly?, ie:
private IControllerFactory _factory;
public void SetControllerFactory(IControllerFactory controllerFactory) {
_factory = controllerFactory;
}
public void SetControllerFactory(Type controllerFactoryType) {
_factory = (IControllerFactory)Activator.CreateInstance(controllerFactoryType);
}
The reason that _factoryThunk is currently defined as a Func<IControllerFactory> is that it's a generic means to support both overloads:
void SetControllerFactory(Type);
void SetControllerFactory(IControllerFactory);
The implementation of the first one uses the fact that _factoryThunk is a Func by declaring that Func inline by using Activator to instantiate the Type lazily:
this._factoryThunk = delegate {
IControllerFactory factory;
try
{
factory = (IControllerFactory) Activator.CreateInstance(controllerFactoryType);
}
catch (Exception exception)
{
throw new InvalidOperationException(string.Format(CultureInfo.CurrentUICulture, MvcResources.ControllerBuilder_ErrorCreatingControllerFactory, new object[] { controllerFactoryType }), exception);
}
return factory;
};
Therefore, the reason the other overload looks like it has a spurious implementation is that since _factoryThunk is declared as a Func, the line you propose wouldn't have even compiled:
_factoryThunk = controllerFactory;
_factoryThunk is a Func<IControllerFactory> whereas controllerFactory is an IControllerFactory -- incompatible types.

StructureMap InstanceInterceptor not being called

I want to intercept the creation of an instance in SM and I'm trying the following but it's not calling the InstanceInterceptor implementation, does anyone know why?
ForRequestedType<IPublishResources>()
.TheDefault
.Is
.OfConcreteType<PublisherService>()
.InterceptWith(new PublisherServiceInterceptor());
The test code uses the ObjectFactory to create instances, and is shown below:
// Given we have a configure object factory in StructureMap...
ObjectFactory.Configure(x => x.AddRegistry(new StructureMapServiceRegistry()));
// When we request a publisher service...
var publisher = ObjectFactory.GetInstance<IPublishResources>();
Cheers
AWC
I could not reproduce your problem in release 2.5.4. Here is my code.
public interface IPublishResources {}
class PublishResources : IPublishResources {}
public class LoggingInterceptor : InstanceInterceptor
{
//this interceptor is a silly example of one
public object Process(object target, IContext context)
{
Console.WriteLine("Interceptor Called");
return context.GetInstance<PublishResources>();
}
}
public class MyRegistry : Registry
{
public MyRegistry()
{
For<IPublishResources>()
.Use<PublishResources>()
.InterceptWith(new LoggingInterceptor());
}
}
[TestFixture]
public class Structuremap_interception_configuraiton
{
[Test]
public void connecting_implementations()
{
var container = new Container(cfg =>
{
cfg.AddRegistry<MyRegistry>();
});
container.GetInstance<IPublishResources>();
}
}
A question. Do you really need to use an Interceptor here? If you only need to define a factory you can do somethign like this.
public interface IPublishResourcesFactory
{
IPublishResources Create();
}
public class MyRegistry : Registry
{
public MyRegistry()
{
For<IPublishResources>().Use(c =>
{
return c.GetInstance<IPublishResourcesFactory>().Create();
});
//or
For<IPublishResources>().Use(c =>
{
//other object building code.
return new PublishResources();
});
}
}