I'm going to add in the necessary infrastructure to bind each request to its own nested container, So in this case having a Container Per Request gives us a unique session (Context Per Request), In my code I'm using the new implementation of ObjectFactory:
public static class SmObjectFactory
{
private static readonly Lazy<Container> _containerBuilder =
new Lazy<Container>(defaultContainer, LazyThreadSafetyMode.ExecutionAndPublication);
public static IContainer Container
{
get { return _containerBuilder.Value; }
}
private static Container defaultContainer()
{
return new Container(ioc =>
{
ioc.For<IUnitOfWork>()
.HybridHttpOrThreadLocalScoped()
.Use<ApplicationDbContext>();
// config
});
}
}
So, for example If I just set a break point in the ApplicationDbContext
's constructor, each time an instance is created. For example in my case I have these controllers:
public partial class HomeController : Controller
{
private readonly IUnitOfWork _uow;
public HomeController(IUnitOfWork uow)
{
_uow = uow;
}
public virtual ActionResult Index()
{
return View();
}
}
public class TestController : Controller
{
private readonly IUnitOfWork _uow;
public TestController(IUnitOfWork uow)
{
_uow = uow;
}
public ActionResult GetData()
{
return Content("Data");
}
}
So the view returned by Index action uses this code to pull in content from TestController
:
@Html.Action("GetData", "Test")
In that example, several instances are created per request!
So I've changed SmObjectFactory
this way:
public class NewObjectFactory
{
public static IContainer Container { get; set; }
static NewObjectFactory()
{
Container = new Container();
Container.Configure(ioc =>
{
ioc.For<IUnitOfWork>()
.HybridHttpOrThreadLocalScoped()
.Use<ApplicationDbContext>();
// config
}
}
Then in the Global.asax
I've added these lines of code for using nested container:
public IContainer Container
{
get
{
return (IContainer)HttpContext.Current.Items["_Container"];
}
set
{
HttpContext.Current.Items["_Container"] = value;
}
}
public void Application_BeginRequest()
{
Container = NewObjectFactory.Container.GetNestedContainer();
}
public void Application_EndRequest()
{
Container.Dispose();
Container = null;
}
And inside Application_Start
:
DependencyResolver.SetResolver(
new StructureMapDependencyResolver(() => Container ?? NewObjectFactory.Container));
And inside of the DependencyResolver I've implemented the factory function this way:
public class StructureMapDependencyResolver : IDependencyResolver
{
private readonly Func<IContainer> _factory;
public StructureMapDependencyResolver(Func<IContainer> factory)
{
_factory = factory;
}
public object GetService(Type serviceType)
{
if (serviceType == null)
{
return null;
}
var factory = _factory();
return serviceType.IsAbstract || serviceType.IsInterface
? factory.TryGetInstance(serviceType)
: factory.GetInstance(serviceType);
}
public IEnumerable<object> GetServices(Type serviceType)
{
return _factory().GetAllInstances(serviceType).Cast<object>();
}
}
Finaly when I run the application I get this error:
No default Instance is registered and cannot be automatically determined for type 'Microsoft.Owin.Security.DataProtection.IDataProtectionProvider'
But when I comment this line in the Startup.cs
file:
ConfigureAuth(app)
everything works and this time the ApplicationDbContext
is created once and then disposed. So that's what I want: Only a single instance of the context is created now and it is correctly disposed of at the end of the web request, It means that the nested container reused the context to satisfy the dependencies of both controllers. :)
Any idea?