I have just landed in dependency injection world.
I have the following custom DbContext-
public partial class SkyTrackerContext: DbContext
{
public SkyTrackerContext(): base()
{
Database.SetInitializer(new SkyTrackerDBInitializer());
}
}
Would like inject SkyTrackerContext in this base controller-
public abstract class BaseController : Controller
{
public BaseController() {}
[Inject]
public SkyTrackerContext MyDbContext { get; set; }
}
Sample usage-
public class LoginController : BaseController
{
public ActionResult ValidateLogin(Login login)
{
var query = MyDbContext.Persons.Where(.....);
}
}
What should I write in NinjectWebCommon.cs to inject this context ?
private static IKernel CreateKernel()
{
var kernel = new StandardKernel();
try
{
kernel.Bind<Func<IKernel>>().ToMethod(ctx => () => new Bootstrapper().Kernel);
kernel.Bind<IHttpModule>().To<HttpApplicationInitializationHttpModule>();
RegisterServices(kernel);
return kernel;
}
catch
{
kernel.Dispose();
throw;
}
}
First, you should avoid method injection. Instead, use constructor injection. In other words:
public abstract class BaseController : Controller
{
protected readonly DbContext context;
public BaseController(DbContext context)
{
this.context = context;
}
...
}
Then, as far as the Ninject config goes, it's extremely simple:
kernel.Bind<DbContext>().To<SkyTrackerContext>().InRequestScope();
Related
I am using ASP.NET Core 2.0
At Startup.cs I have
services.AddDbContext<MailDBServicesContext>(optionsSqLite =>
{
optionsSqLite.UseSqlite("Data Source=Mail.db");
});
I have created a model and a DbContext where DbContext is:
public class MailDBServicesContext : DbContext
{
public MailDBServicesContext(DbContextOptions<MailDBServicesContext> options)
: base(options)
{
}
public DbSet<MailCountSentErrorMails> DbSetMailCountSentErrorMails { get; set; }
}
from a Class helper I need to pass DbContextOptions and my question is how can I tell to use the options from the Startup.cs ConfigureServices method
using (var db = new MailDBServicesContext())
{
}
It should be enough to simply inject MailDBServicesContext into your controller or a service class, for example.
public class SomeDataService
{
private readonly MailDBServicesContext _dbContext;
public SomeDataService(MailDBServicesContext dbContext)
{
_dbContext = dbContext ?? throw new ArgumentNullException(nameof(dbContext));
}
public async Task AddMailCounts()
{
_dbContext.DbSetMailCountSentErrorMails
.Add(new MailCountSentErrorMails { CountSentMails = 55 });
await _dbContext.SaveChangesAsync();
}
}
Other DB context configuration options are defined in Configuring a DbContext on MSDN.
Update
Make sure to register your service in DI, i.e. ConfigureServices method.
public void ConfigureServices(IServiceCollection services)
{
services.AddTransient<ISomeDataService, SomeDataService>();
services.AddDbContext<MailDBServicesContext>(optionsSqLite =>
{
optionsSqLite.UseSqlite("Data Source=Mail.db");
});
services.AddMvc();
}
Then make a call to AddMailCounts() in your controller.
public class HomeController : Controller
{
private readonly ISomeDataService _dataService;
public HomeController(ISomeDataService dataService)
{
_dataService = dataService ?? throw new ArgumentNullException(nameof(dataService));
}
public IActionResult Index()
{
_dataService.AddMailCounts();
return View();
}
}
Now every time you load homepage, a record is inserted into DbSetMailCountSentErrorMails table.
You can find working solution on my GitHub.
I've been at it for days, but I can't get Unity to inject anything with RegisterType<> into my Controller. I'm using Web Api 2, in Visual Studio 2015, with Unity 4. Whenever I try to inject IUnitOfWork or IRFContext, I get "message": "An error occurred when trying to create a controller of type 'ClPlayersController'. Make sure that the controller has a parameterless public constructor.".
I'm using the Unity.AspNet.WebApi to bootstrapp into WebApi. Below is my UnityWebApiActivator
[assembly: WebActivatorEx.PreApplicationStartMethod(typeof(mycompany.project.api.UnityWebApiActivator), "Start")]
[assembly: WebActivatorEx.ApplicationShutdownMethod(typeof(mycompany.project.api.UnityWebApiActivator), "Shutdown")]
namespace mycompany.project.api
{
public static class UnityWebApiActivator
{
public static void Start()
{
var resolver = new UnityDependencyResolver(UnityConfig.GetConfiguredContainer());
GlobalConfiguration.Configuration.DependencyResolver = resolver;
}
public static void Shutdown()
{
var container = UnityConfig.GetConfiguredContainer();
container.Dispose();
}
}
}
I'm using a Start.cs due to Owin.
[assembly: OwinStartup(typeof(mycompany.project.api.Startup))]
namespace mycompany.project.api
{
public class Startup
{
public void Configuration(IAppBuilder app)
{
HttpConfiguration config = new HttpConfiguration();
ConfigureOAuth(app);
config.DependencyResolver = new UnityDependencyResolver(UnityConfig.GetConfiguredContainer());
WebApiConfig.Register(config);
app.UseCors(Microsoft.Owin.Cors.CorsOptions.AllowAll);
app.UseWebApi(config);
}
public void ConfigureOAuth(IAppBuilder app)
{
OAuthAuthorizationServerOptions OAuthServerOptions = new OAuthAuthorizationServerOptions()
{
AllowInsecureHttp = true,
TokenEndpointPath = new PathString("/token"),
AccessTokenExpireTimeSpan = TimeSpan.FromDays(1),
Provider = new SimpleAuthorizationServerProvider(),
RefreshTokenProvider = new SimpleRefreshTokenProvider()
};
// Token Generation
app.UseOAuthAuthorizationServer(OAuthServerOptions);
app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());
}
}
}
My WebApiConfig.cs is below:
namespace mycompany.project.api
{
public static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
log4net.Config.XmlConfigurator.Configure();
config.MapHttpAttributeRoutes();
config.EnableSystemDiagnosticsTracing();
config.Services.Add(typeof(IExceptionLogger),
new SimpleExceptionLogger(new LogManagerAdapter()));
config.Services.Replace(typeof(IExceptionHandler), new GlobalExceptionHandler());
}
}
}
My UnityConfig.cs is below
namespace mycompany.project.api
{
public class UnityConfig
{
#region Unity Container
private static Lazy<IUnityContainer> container = new Lazy<IUnityContainer>(() =>
{
var container = new UnityContainer();
RegisterTypes(container);
return container;
});
public static IUnityContainer GetConfiguredContainer()
{
return container.Value;
}
#endregion
public static void RegisterTypes(IUnityContainer container)
{
var config = new MapperConfiguration(cfg =>
{
//AutoMapper bindings
});
container.RegisterInstance<IMapper>(config.CreateMapper());
container.RegisterType<IRFContext, RFContext>(new PerThreadLifetimeManager());
container.RegisterType<IUnitOfWork, UnitOfWork>();
XmlConfigurator.Configure();
var logManager = new LogManagerAdapter();
container.RegisterInstance<ILogManager>(logManager);
}
}
}
All that I have in my Global.asax is below:
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Error()
{
var exception = Server.GetLastError();
if (exception != null)
{
var log = new LogManagerAdapter().GetLog(typeof(WebApiApplication));
log.Error("Unhandled exception.", exception);
}
}
}
If my Controller is like this, it works fine:
public class ClPlayersController : ApiController
{
private readonly IMapper mapper;
public ClPlayersController(IMapper _mapper, IUnityContainer container)
{
mapper = _mapper;
}
But placing IUnitOfWork, like below, or the IRFContext, I get the error:
private readonly IMapper mapper;
private readonly IUnitOfWork unitOfWork;
public ClPlayersController(IMapper _mapper, IUnityContainer container, IUnitOfWork _unitOfWork)
{
mapper = _mapper;
unitOfWork = _unitOfWork;
}
I can't find, for the life of me, what I'm doing wrong. If I loop through the container.Registrations on the constructor, I find the mappings, but they refuse to get injected. Any hints?
EDIT
Below is the code for UnitOfWork and RFContext
namespace mycompany.project.data.configuracao
{
public class UnitOfWork : IUnitOfWork
{
private readonly IRFContext _rfContext;
private bool _disposed = false;
public UnitOfWork(IRFContext rfContext)
{
_rfContext = rfContext;
}
public void Commit()
{
if (_disposed)
{
throw new ObjectDisposedException(this.GetType().FullName);
}
_rfContext.SaveChanges();
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
if (_disposed) return;
if (disposing && _rfContext != null)
{
_rfContext.Dispose();
}
_disposed = true;
}
}
}
and
namespace mycompany.project.data.configuracao
{
public interface IUnitOfWork : IDisposable
{
void Commit();
}
}
and RFContext is a basic POCO generated DBContext
namespace mycompany.project.data.configuracao
{
using System.Linq;
public class RFContext : System.Data.Entity.DbContext, IRFContext
{
public System.Data.Entity.DbSet<ClGrupoEconomico> ClGrupoEconomicoes { get; set; }
//all my DbSets
public System.Data.Entity.DbSet<SpTipoLog> SpTipoLogs { get; set; }
static RFContext()
{
System.Data.Entity.Database.SetInitializer<RFContext>(null);
}
public RFContext()
: base("Name=RFContext")
{
}
public RFContext(string connectionString)
: base(connectionString)
{
}
public RFContext(string connectionString, System.Data.Entity.Infrastructure.DbCompiledModel model)
: base(connectionString, model)
{
}
public RFContext(System.Data.Common.DbConnection existingConnection, bool contextOwnsConnection)
: base(existingConnection, contextOwnsConnection)
{
}
public RFContext(System.Data.Common.DbConnection existingConnection, System.Data.Entity.Infrastructure.DbCompiledModel model, bool contextOwnsConnection)
: base(existingConnection, model, contextOwnsConnection)
{
}
protected override void Dispose(bool disposing)
{
base.Dispose(disposing);
}
protected override void OnModelCreating(System.Data.Entity.DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Configurations.Add(new ClGrupoEconomicoConfiguration());
//all my Configuration classes
modelBuilder.Configurations.Add(new SpTipoLogConfiguration());
}
public static System.Data.Entity.DbModelBuilder CreateModel(System.Data.Entity.DbModelBuilder modelBuilder, string schema)
{
modelBuilder.Configurations.Add(new ClGrupoEconomicoConfiguration(schema));
//all my configuration classes
modelBuilder.Configurations.Add(new SpTipoLogConfiguration(schema));
return modelBuilder;
}
}
}
Unfortunately the exception you are seeing can occur for several reasons. One of them is when Unity cannot resolve one or more of your injections.
An error occurred when trying to create a controller of type
'FooController'. Make sure that the controller has a parameterless
public constructor.
So, based on the information in your question your setup is apparently correct, since IMapper can be injected. Therefore I guess that UnitOfWork and RFContext have dependencies that Unity cannot resolve. Maybe a repository?
UPDATE:
The problem here is that your RFContext has several constructors.
https://msdn.microsoft.com/en-us/library/cc440940.aspx#cnstrctinj_multiple
When a target class contains more than one constructor with the same
number of parameters, you must apply the InjectionConstructor
attribute to the constructor that the Unity container will use to
indicate which constructor the container should use. As with automatic
constructor injection, you can specify the constructor parameters as a
concrete type, or you can specify an interface or base class for which
the Unity container contains a registered mapping.
In this case Unity doesn't know how to resolve your RFContext, and will try to use the constructor with the most parameters. You can solve it by using
container.RegisterType<IRFContext, RFContext>(new InjectionConstructor());
Using a combination provided from this example and this implementation I am trying to create a solution that decouples the UnitOfWork class from the individual repositories, as they violate the Open-Closed Principle, since every time you added a new repository you would have to modify the UnitOfWork class. I am using Unity as the IoC container to wire up dependencies.
The problem I have is that in automatically wiring up the UnitOfWork, IDbContext and the repositories (IEmployeeRepository and ICustomerRepository) using Unity, the repositories will be injected with separate instances of the UnitOfWork, which, of course, defeats the purpose. I need to share the context across the repositories, and it seems I am missing a piece to this puzzle - at the moment (see Service layer) the UnitOfWork instantiated will be different to the UnitOfWork for each of repositories.
How do inject the IUnitOfWork into the service layer and pass this instantiated shared UnitOfWork class to the respective repositories, using Unity and dependency injection?
Here's my proposed (fabricated) solution:
Repositories
public interface IRepository<TEntity> where TEntity : class
{
TEntity Create();
// omitted for brevity
}
public class Repository<TEntity> : IRepository<TEntity>
where TEntity : class
{
private readonly DbContext _context;
public Repository(IUnitOfWork uow)
{
_context = uow.Context;
}
public virtual TEntity Create(TEntity entity)
{
return _context.Set<TEntity>().Add(entity);
}
// omitted for brevity
}
public interface IEmployeeRepository : IRepository<Employee>
{
}
public interface ICustomerRepository : IRepository<Customer>
{
}
public class EmployeeRepository : Repository<Employee>
{
public EmployeeRepository(IUnitOfWork uow)
: base(uow)
{
}
}
public class CustomerRepository : Repository<Customer>
{
public CustomerRepository(IUnitOfWork uow)
: base(uow)
{
}
}
DbContext Factory
public interface IDbContextFactory
{
DbContext GetContext();
}
public class DbContextFactory : IDbContextFactory
{
private readonly DbContext _context;
public DbContextFactory()
{
_context = new MyDbContext("ConnectionStringName");
}
public DbContext GetContext()
{
return _context;
}
}
Unit Of Work
public interface IUnitOfWork
{
void SaveChanges();
DbContext Context { get; }
}
public class UnitOfWork : IUnitOfWork, IDisposable
{
private readonly DbContext _context;
private bool disposed = false;
public UnitOfWork(IDbContextFactory contextFactory)
{
_context = contextFactory.GetContext();
}
public void SaveChanges()
{
if (_context != null)
{
_context.SaveChanges();
}
}
public DbContext Context
{
get { return _context; }
}
protected virtual void Dispose(bool disposing)
{
if (!disposed)
{
if (disposing)
{
_context.Dispose();
}
}
disposed = true;
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
}
Service
public class CompanyService
{
private readonly IUnitOfWork _uow;
private readonly IEmployeeRepository _employeeRepository;
private readonly ICustomerRepository _customerRepository;
public CompanyService(IUnitOfWork uow, IEmployeeRepository employeeRepository, ICustomerRepository customerRepository)
{
_uow = uow;
_employeeRepository = employeeRepository;
_customerRepository = customerRepository;
}
// over-simplified example method
public void AddEmployeeAndCustomer()
{
_employeeRepository.Create(new Employee {Id = 1, Name = "Test Employee"});
_customerRepository.Create(new Customer { Id = 2, Name = "Test Customer" });
_uow.SaveChanges();
}
}
I think what you are looking for is a per request lifetime manager so that you only get one UnitOfWork instance and one DbContext instance for the duration of a request. Unity 3 has the Unity bootstrapper for ASP.NET MVC which has a PerRequestLifetimeManager which lets you do this.
If you are not using ASP.NET then you could probably use a PerResolveLifetimeManager. Another approach I've seen is a HierarchicalLifetimeManager combined with a child container (which makes the registrations a singleton within the child container).
I would like to how to correct build and handle with NHibernate repository and session in view models classes.
For example I use Caliburn Micro framework with Castle Windsor boostraper.
First I created NHibernate repository:
public interface IRepository{//I omitted not needed code for simplification}
public class NHibRepository: IRepository
{
private ISession _session;
public NHibRepository(ISession session)
{
_session=session;
}
// I omitted not needed code for simplification
}
Second I definied some POCO class and mapping class with Fluent NHibernate.
public class User{}
public class Profile{}
public class Album{}
public class UserMap : ClassMap<User>{}
public class ProfileMap : ClassMap<Profile>{}
public class AlbumMap : ClassMap<Album>{}
Now I need use NHibernate repositories in my view models.
public interface IViewModelA{}
public class ViewModelA : ScreenViewModel, IViewModelA
{
public NHibRepository<User> UserRepo{get;set;}
public NHibRepository<Profile> ProfileRepo{get;set;}
}
public interface IViewModelB{}
public class ViewModelB : Screen, IViewModelB
{
public NHibRepository<Profile> ProfileRepo{get;set;}
public NHibRepoistory<Album> AlbumRepo{get;set;}
}
When I am creating repository class for some entity class I need pass session to NHibRepository construtor.
UserRepo= new NHibRepository<User>(NHIBERNATE SESSION);
Until now I used some helper class for creating Nhibernate session and init repository.
Helper class is here:
public class FluentNHibHelper
{
private ISessionFactory _sessionFactory;
public FluentNHibHelper(IPersistenceConfigurer db, Assembly asm)
{
InitializeSessionFactory(db, asm);
}
private void InitializeSessionFactory(IPersistenceConfigurer db, Assembly asm)
{
_sessionFactory = Fluently.Configure()
.Database(db)
.Mappings(m => m.FluentMappings.AddFromAssembly(asm))
.ExposeConfiguration(cfg => new SchemaUpdate(cfg).Execute(true, true))
.BuildSessionFactory();
}
public ISession OpenSession()
{
return _sessionFactory.OpenSession();
}
}
with this class I created repository class:
private const string ConnString =
#"Server=TestMachine\SQLEXPRESS;Database=TEST;Trusted_Connection=True;";
UserRepo = new NHibRepository<User>(
new FluentNHibHelper(MsSqlConfiguration.MsSql2008.ConnectionString(ConnString),
Assembly.GetExecutingAssembly())
.OpenSession());
Now I am confuse I don’t what is the best way for creating repository object in view models.
For example in bootstraper class can I somehow register repository class ?
public class CastleBootstrapper : Bootstrapper<IShellViewModel>
{
private IWindsorContainer _windsorContainer;
protected override void Configure()
{
_windsorContainer = new WindsorContainer();
//register repository class here ???
}
}
Can anybody help me? Thank you very much
Sorry for my english.
I use the following in an ASP.net MVC application. Castle.Windsor takes care of creating the ISession dependency for each repository.
//Located in your application startup
protected IWindsorContainer CreateContainer()
{
container = new WindsorContainer();
container.Install(
new PersistenceInstaller(),
new RepositoryInstaller()
//, other installers here
);
return container;
}
public class PersistenceInstaller : IWindsorInstaller
{
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.AddFacility<PersistenceFacility>();
}
}
public class PersistenceFacility : AbstractFacility
{
protected override void Init()
{
NHibernate.Cfg.Configuration config = BuildDatabaseConfiguration();
Kernel.Register(
Component.For<ISessionFactory>()
.UsingFactoryMethod(config.BuildSessionFactory),
Component.For<ISession>()
.UsingFactoryMethod(k => k.Resolve<ISessionFactory>().OpenSession())
.LifeStyle.Trasient
);
}
private NHibernate.Cfg.Configuration BuildDatabaseConfiguration()
{
return Fluently.Configure()
.Database(SetupDatabase)
.Mappings(m => m.HbmMappings.AddFromAssemblyOf<Entity>())
.ExposeConfiguration(ConfigurePersistence)
.BuildConfiguration();
}
protected virtual IPersistenceConfigurer SetupDatabase()
{
return MsSqlConfiguration.MsSql2008
.UseOuterJoin()
.ConnectionString(x => x.FromConnectionStringWithKey("ApplicationServices"))
.ShowSql();
}
protected virtual void ConfigurePersistence(NHibernate.Cfg.Configuration config)
{
SchemaMetadataUpdater.QuoteTableAndColumns(config);
}
protected virtual bool IsDomainEntity(Type t)
{
return typeof(DomainBase).IsAssignableFrom(t);
}
}
public class RepositoryInstaller : IWindsorInstaller
{
public void Install(IWindsorContainer container, IConfigurationStore store)
{
container.Register(Find().Configure(ConfigureLifeStyle()));
}
private ConfigureDelegate ConfigureLifeStyle()
{
return c => c.LifeStyle.Transient;
}
private BasedOnDescriptor Find()
{
return AllTypes.FromAssemblyContaining<NHRepository>()
.Where(type => type.Name.EndsWith("Repository"))
.WithService
.AllInterfaces();
}
}
i am creating custom membership provider using ninject for binding to sql classes.
my class in looks like
public MyMembershipProvider(IUsersRepository userRepository)
{
this.userRepository = userRepository;
}
How can i create from this parameterless constructor?
kernel.Bind<IUsersRepository>().To<UsersRepository>();
kernel.Bind<MembershipProvider>().To<MyMembershipProvider>();
and then:
public class AccountController : Controller
{
private readonly MembershipProvider _membershipProvider;
public AccountController(MembershipProvider membershipProvider)
{
_membershipProvider = membershipProvider;
}
public ActionResult Foo()
{
// TODO: Use the membership provider to do some processing
return View();
}
}