ObjectSet.Context vs DbSet - entity-framework-4.1

i used to use the ObjectSet in EF 4.0, I could get the underlying Context for this ObjectSet using
myObjectSet.Context which returns ObjectContext.
Now with DbSet in Ef4.1, what is the equivalent ??

EF 4.1 does not offer a public API to get the DbContext from the DbSet instance. You would have to use Reflections API to get the DbContext instance.
Edit
One workaround would be to pass around the DbContext instace with DbSet instance.
Eg if you had a constructor that took only a DbSet instance. Pass the DbContext instace also.
public MyService(DbContext context, DbSet<MyClass> mySet){}
Other method would be to open up the EntityFramewrk.dll inside Reflector and find out how to get the DbContext instace by accessing the internal/private fields of DbSet. I wouldn't advice you to use this because implementations can change.

Related

How to use values from porperty files in a global context with Junit5 and CitrusExtension

Maybe I'm on the wrong course or totally misunderstanding something.
I've merged a Citrus IntegrationTest from Junit4Runner to Junit5 (with CitrusExtension).
There is an EndpointConfiguration class
#Configuration
#PropertySource("test-setup.properties")
#PropertySource("service-paths.properties")
public class RestEndpointConfig {
#Value("${testenv.host}") //defined in test-setup.properties
private String host;
...
}
And a TestClass
#ExtendWith(CitrusExtension.class)
#RunWith(JUnitPlatform.class)
public class BaseIT{
#CitrusEndpoint
protected HttpClient httpClient;
#Value("${rest.session}") //defined in service-paths.properties
private String sessionPath;
}
In the test class I want to access values defined in the service-paths.properties file.
This worked with JUnit4 but after the changes to JUnit5 it seems that the properties are no longer available in a 'global' context.
Turning the log level to 'debug' shows, that the properties file is loaded.
So my question is: What do I need to change in order to get access to the service-paths properies in my IT classes. What am I missing, what is best practice in this case?
Thanks in advance for any feedback.
Property value resolving via #Value annotation is a core Spring framework feature. So you need to add SpringExtension to your JUnit5 test. You can do this in addition to using the CitrusExtension.

Injecting DbContext into FileProvider in ASP.NET Core

I am trying to load some of the views from the database as described in here. So I want to use EF Core in the File provider.
RazorViewEngineOptions has a FileProviders property that you can add your file provider to. The problem is that you have to give it an instace of the file provider. So you'll need to instantiate all of the file providers' dependencies right there in Startup's ConfigureServices method.
Currently I inject an instance of IServiceProvider into the Configure method of Startup. Then I store the instance in a field (called _serviceProvider):
IServiceProvider _serviceProvider;
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IServiceProvider provider)
{
_serviceProvider = provider;
...
}
Then in ConfigureServices I use that field to instanciate the UIDbContext.
services.Configure<RazorViewEngineOptions>(options =>
{
var fileProvider = new DbFileProvider(_serviceProvider.GetService<UIDbContext>());
options.FileProviders.Add(fileProvider);
});
Is there any better way to be able to inject the UIDbContext into the DbFileProvider constructor Or any way to instantiate a UIDbContext inside DbFileProvider without IServiceProvider?
You don't want to use DbContext as a file provider source the way you did.
DbContext isn't thread-safe, so it won't work when you have one single DbContext instance for the whole provider, because multiple requests could call the DbContext and it's operation more than once at the same time, resulting in exception when trying to execute 2 queries in parallel.
You'd have to instantiate a connection (like in the linked article) or DbContext per IFileInfo/IDirectoryContents instance.
DbContextOptions<UIDbContext> should be registered as singleton, so you can resolve it onceinside Configure` w/o any issues and pass it to your provider.
Alternatively you can also call DbContextOptionsBuilder and build/construct a DbContextOptions<T>, but then you have to repeat the configuration for you did inside AddDbContext (i.e. .UseSqlServer()).
However it can be useful, as it allows you to set different settings (i.e. changing the way how includes, errors etc. are logged).

Managing RavenDb session in Windsor under NServiceBus

I'm using NServiceBus (3.2.2), RavenDB (1.2.2017-Unstable) and Windsor (3.0.0.4001) in an MVC 4 project.
I have a IHandleMessages class that handles 3 different messages, and that needs an IDocumentSession, and therefore defines a property such as:
public IDocumentSession DocumentSession { get; set; }
I've copied the RavenDbUnitOfWork implementation from NServiceBus' website
I've registered IDocumentStore, IDocumentSession and IManageUnitsOfWork in my Windsor container as follow:
container.Register(
Component
.For<IManageUnitsOfWork>()
.ImplementedBy<RavenUnitOfWork>()
.LifestyleTransient()
);
container.Register(
Component
.For<IDocumentStore>()
.UsingFactoryMethod(k => DocumentStoreHolder.DocumentStore)
.LifestyleSingleton(),
Component
.For<IDocumentSession>()
.UsingFactoryMethod(k => k.Resolve<IDocumentStore>().OpenSession())
.LifestyleTransient()
);
NServiceBus is configured to use my container:
Configure.With()
.CastleWindsorBuilder(container);
I'm encountering the problem that the UnitOfWork and the message handler receive different instances of the DocumentSession. This means that objects stored in the session in the message handler are not saved, since SaveChanges() is called on a different DocumentSession.
Removing the Transient lifestyle causes different kind of problems, that result in concurrency/conflicts when updating objects from RavenDb, since (probably) the message handler keeps getting the same instance of the DocumentSession, which holds a cached version of the updated object.
Update:
As suggested, I've tried changing the registration of the IDocumentSession in Windsor, to the Scope lifestyle, like this:
Component
.For<IDocumentSession>()
.UsingFactoryMethod(k => k.Resolve<IDocumentStore>().OpenSession())
.LifestyleScope()
This causes exceptions when the container tries to resolve the MVC Controller, saying that the scope was not found, and asking if I forgot to call BeginScope().
You need to have a scope of Per Message, not transient or singleton.
I am assuming that your mvc controller has a direct dependency on the IDocumentStore. You need to call container.BeginScope() before each request from the web. You can either do this as an action filter attribute http://msdn.microsoft.com/en-us/library/system.web.mvc.actionfilterattribute.aspx or as an AOP aspect on the controller itself http://cangencer.wordpress.com/2011/06/02/asp-net-mvc-3-aspect-oriented-programming-with-castle-interceptors/.
The issue is you need different lifestyles when using nservicebus in an asp.net mvc website when sharing the IDocumentSession in the same container.
For ASP.NET MVC you need a PerWebRequest lifestyle and for NServiceBus you need the Scoped lifestyle.
To do that i've used the hybrid lifestyle code in the castle contrib project:
https://github.com/castleprojectcontrib/Castle.Windsor.Lifestyles/tree/master/Castle.Windsor.Lifestyles
When calling from an ASP.NET context, it uses the WebRequestScopeAccessor. For NServicebus you need the LifetimeScopeAccessor. This is not in the contrib project, but is easy to add:
public class HybridPerWebRequestLifetimeScopeScopeAccessor : HybridPerWebRequestScopeAccessor
{
public HybridPerWebRequestLifetimeScopeScopeAccessor()
: base(new LifetimeScopeAccessor())
{
}
}
And in your registration code you need something like:
container.Register(Component.For<IDocumentSession>().LifestyleScoped<HybridPerWebRequestLifetimeScopeScopeAccessor>().UsingFactoryMethod(() => RavenDbManager.DocumentStore.OpenSession()));
And here's an implementation for Rhino Service Bus i used before switching to nservicebus:
https://gist.github.com/4655544

entity and repository pattern with ninject, Dispose Issue

I have build my site using entity and repository pattern with ninject injection. My problem is my connections don't seem to get disposed. I have around 30 repositories (one for each table) and I get sql expiration timout preety quick. I can't use the regular using statement because the code recognize only the interface before the injection.
(in each controler I have my repositories interface instances which get injected via ninject).
I have searched the net but couldn't find a solution that was accurate for me.
can anyone please help me?
code example:
this is in the ninject controller under addBindings():
ninjectKernel.Bind<IMovieRepository>().To<MovieRepository>().InRequestScope();
and one of my repositories:
public class MovieRepository : IMovieRepository, IDisposable
{
private Entities dataContext = new Entities();
public System.Data.Entity.DbContext DbContext
{
get { return dataContext ?? (dataContext = new Entities()); }
}
public void Dispose() { dataContext.Dispose(); }
}
and in the Global.asax file:
ControllerBuilder.Current.SetControllerFactory(new NinjectControllerFactory() as IControllerFactory);
I would guess that your repositories (and therefore presumably your DbContexts) are being bound in transient scope, which I believe means a new one will be created every time Ninject needs to inject one somewhere. I'm not certain but I'm guessing then that these are all staying around for the lifetime of your application and maybe not being disposed.
Try binding your repositories in request scope, so that they are created and disposed per web request.
e.g.
Bind<IFooRepository>().To<ConcreteFooRepository>().InRequestScope();
From the Ninject wiki:
There are four built-in scopes available in Ninject:
Transient - A new instance of the type will be created each time one is requested. (This is the default scope). Binding method is .InTransientScope()
Singleton - Only a single instance of the type will be created, and the same instance will be returned for each subsequent request. Binding method is .InSingletonScope()
Thread - One instance of the type will be created per thread. Binding method is .InThreadScope()
Request - One instance of the type will be created per web request, and will be destroyed when the request ends. Binding method is .InRequestScope()
This kind of problem usually occur if long living objects depend on shorter living objects. E.g. A singleton service uses a repository in request scope.

Is Entity Framework 4.1 supporting protected or private collection mapping?

I remember the last version of EF wasn't supporting protected or private collection mapping like NHibernate does.
You had to do something like that
public class Post
{
...
public virtual ICollection<Tag> Tags { get; private set; }
Is there a way to avoid someone from calling this collection directly ? i would prefer encapsulating it in a method instead to have full control on it. However this was needed by EF in order to do the relationship. Was this changed ?
EDIT: Normally we should be able to use IEnumerable instead of ICollection (as it is supported with NHibernate) but it seem not supported in EF.
Thanks.
What you show in your example is mapping of private or protected collection, isn't it? - your setter is private and it is supported when using EDMX file for mapping.
In case of code-first it is not supported because both fluent API and conventions are able to map only properties which are visible to them.