Nhibernate Session configuration for windows application - nhibernate

I'm using NHibernate in a Windows Forms application and I need to change the connection string in a repository class. But when I try to get the current session I get this error:
No CurrentSessionContext configured
My Repository class is as below:
public class UserRepository : Repository<User>, IUserRepository
{
public UserRepository(ISessionFactory planningUow) : base(planningUow)
{
planningUow.GetCurrentSession().Connection.ConnectionString = "test";
}
public IQueryable<User> GetByUserId(Guid id)
{
return Session.Query<User>().Where(bd => bd.UserId == id).AsQueryable();
}
public IQueryable<User> GetAllUsers()
{
return Session.Query<User>().AsQueryable();
}
public IQueryable<User> GetByUserPassword(string userName, string password)
{
return Session.Query<User>().Where(x => x.UserName == userName && x.Password == password).AsQueryable();
}
}
and my Fluent Nhibernate configuration code is as below:
public ISessionFactory CreateSessionFactory()
{
try
{
return Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2008.ConnectionString(x => x.FromConnectionStringWithKey(ConnectionString)))
.Mappings(m =>
m.FluentMappings
.AddFromAssemblyOf<UserMap>())
.ExposeConfiguration(config => { new SchemaUpdate(config).Execute(false, true); })
.BuildSessionFactory();
}
catch (Exception ex)
{
throw ex;
}
}
how can I get the current session to get the connection string?

I don't think you'll be able to alter the connection settings once the SessionFactory is built. However, you can supply your own connection to a Session. How you will be able to do this with your use of contextual sessions is not clear as you haven't included that code.
Depending on how many different connections you plan to use, a multiple SessionFactory approach might be best.

Related

How to create DbContext

below default code in controller working fine
public ProductController(appDbContext parmContext)
{
_context = parmContext;
}
now I want to add DAL and in that, getting error creating object of type appDbContext, what to pass/set for parmContext?
below is the connection in Startup.cs
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
services.AddDbContext<appDbContext>(config =>
{
config.UseMySql(Configuration.GetConnectionString("PreSales"));
});
}
Below is the code I want to use
public IEnumerable<ProductStatusMaster> GetProductStatusFRdal()
// here I ant to create object of DBcontext (i.e. _context)
{
try
{
var msm = _context.ProductStatusMaster
.Where(s => s.ActiveYn == 1 )
.OrderBy(s => s.Status)
.ToList();
return msm;
}
catch
{
throw;
}
}
Let me get an answer.
There are 2 ways to realize code you want.
1) Through Controller DI.
2) Through Service Locator pattern (antipattern).
By the code:
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
services.AddDbContext<appDbContext>(config =>
{
config.UseMySql(Configuration.GetConnectionString("PreSales"));
});
}
you set up dependency for DbContext and configure connection parameters. So, for the first method you should pass the dependency through controller. Possible code will be like this:
public class MyTestAppController
{
private appDbContext _context;
public MyTestApController(appDbContext externalAppDbContext)
{
_context = externalAppDbContext;
}
public IEnumerable<ProductStatusMaster> GetProductStatusFRdal()
{
try
{
var msm = _context.ProductStatusMaster
.Where(s => s.ActiveYn == 1 )
.OrderBy(s => s.Status)
.ToList();
return msm;
}
catch
{
throw;
}
}
}
2) Using Service Locator pattern
In this case you should use IServiceProvider dependency. Code example like this:
public class MyTestAppController
{
private IServiceProvider _provider;
public MyTestAppController(IServiceProvider provider) => _provider = provider;
public IEnumerable<ProductStatusMaster> GetProductStatusFRdal()
{
var _context = _provider.GetService<appDbContext>();
try
{
var msm = _context.ProductStatusMaster .Where(s => s.ActiveYn == 1 )
.OrderBy(s => s.Status) .ToList(); return msm;
}
catch { throw; }
}
}

SignalR OnDisconnected event not persisting data to DB

I have a SignalR hub in which I'm injecting service classes which persist data to a local SQL Server instance via Castle Windsor.
The hub looks like:
[Authorize]
public class MyHub : Hub
{
private readonly IHubService _hubService;
private readonly IHubUserService _hubUserService;
private readonly IUserService _userService;
public MyHub(IHubService hubService, IHubUserService hubUserService, IUserService userService)
{
_hubService = hubService;
_hubUserService = hubUserService;
_userService = userService;
}
public async Task JoinHub(Guid hubId)
{
var hub = _hubService.GetHubById(hubId);
if (hub == null)
throw new NotFoundException(String.Format("Hub ({0}) was not found.", hubId.ToString()));
var userName = Context.User.Identity.Name;
var user = _userService.GetUserByUserName(userName);
if (user == null)
throw new NotFoundException(String.Format("User ({0}) was not found.", userName));
var hubUser = new HubUser
{
User = user,
Hub = hub,
ConnectionId = Context.ConnectionId
};
// Persist a new HubUser to the DB
hubUser = _hubUserService.InsertHubUser(hubUser);
await Groups.Add(Context.ConnectionId, hub.Id.ToString());
Clients.Group(hub.Id.ToString()).addChatMessage(userName + " has joined.");
}
public async Task LeaveHub()
{
var userName = Context.User.Identity.Name;
var hubUser = _hubUserService.GetHubUserByUserName(userName);
// Removes HubUser from the DB
_hubUserService.RemoveHubUser(hubUser);
await Groups.Remove(Context.ConnectionId, hubUser.Hub.Id.ToString());
Clients.Group(hubUser.Hub.Id.ToString()).addChatMessage(userName + " has left.");
}
public override Task OnDisconnected(bool stopCalled)
{
var userName = Context.User.Identity.Name;
var hubUser = _hubUserService.GetHubUserByUserName(userName);
// Removes HubUser from the DB
_hubUserService.RemoveHubUser(hubUser); // This line executes but does not persist anything to DB
Groups.Remove(Context.ConnectionId, hubUser.Hub.Id.ToString());
Clients.Group(hubUser.Hub.Id.ToString()).addChatMessage(userName + " has left.");
return base.OnDisconnected(stopCalled);
}
}
When calling JoinHub and LeaveHub methods from the client, everything works fine. However, when the OnDisconnected method fires, nothing is deleted from the database. I can see that the code does indeed execute, but the record remains in the DB and does not get deleted.
I'm wondering if perhaps my nhibernate session is not committing the transaction to the database due to castle windsor's dependency lifetimes or something, however, it's odd that LeaveHub executes as expected but the same code does not in the OnDisconnected method.
My dependencies are registered with the following configuration as per this blog post.
Kernel.Register(
//Nhibernate session factory
Component.For<ISessionFactory>().UsingFactoryMethod(CreateNhSessionFactory).LifeStyle.Singleton,
//Nhibernate session
Component.For<ISession>().UsingFactoryMethod(kernel => kernel.Resolve<ISessionFactory>().OpenSession()).LifeStyle.HybridPerWebRequestTransient()
);
and I also register an interceptor to implement a unit of work pattern:
// Unitofwork interceptor
Component.For<NhUnitOfWorkInterceptor>().LifeStyle.HybridPerWebRequestTransient()
If anyone can give any input on why the method LeaveHub works correctly and why it fails to persist anything in the OnDisconnected method, that'd be greatly appreciated.
Just an FYI Nhibernate Sessions don't do so well using async as they are not threadsafe at all. Try running things synchronously and see what you get.
Is Nhibernate set to flush on transaction commit? I can't comment becasue I am a newbie but I ran into this issue some time ago. I am not using FluentNhibernate but I am sure there is a config option to set flush on transaction commit. This is assuming you are wrapping all open session calls in a transaction. I use something like this for sessions. Also go get Nhibernate Profiler it is a godsend.
public class SessionManager : ISessionManager
{
private readonly ISessionFactory _sessionFactory;
private ISession _currentSession;
private ITransaction _currentTransaction;
public SessionManager(ISessionFactory sessionFactory)
{
_sessionFactory = sessionFactory;
}
public ISession OpenSession()
{
if (CurrentSessionContext.HasBind(_sessionFactory))
{
_currentSession = _sessionFactory.GetCurrentSession();
}
else
{
_currentSession = _sessionFactory.OpenSession();
CurrentSessionContext.Bind(_currentSession);
}
CurrentSessionContext.Bind(_currentSession);
_currentTransaction = _currentSession.BeginTransaction();
return _currentSession;
}
public void Dispose()
{
try
{
if (_currentTransaction != null && _currentTransaction.IsActive)
_currentTransaction.Commit();
}
catch (Exception)
{
if (_currentTransaction != null) _currentTransaction.Rollback();
throw;
}
finally
{
if (_currentSession != null)
{
if (_currentTransaction != null) _currentTransaction.Dispose();
_currentSession.Close();
}
}
}
}
Here is my configuration, I am using it on several apps. On a side not there is a reason I don't use FluentNhibernate, The mapping by code built in is awesome and flexible. Let me know I can send you some sample mappings.
public class SessionFactoryBuilder
{
public static ISessionFactory BuildSessionFactory(string connectionString)
{
var cfg = new Configuration();
cfg.DataBaseIntegration(db =>
{
db.Dialect<MsSql2012Dialect>();
db.Driver<Sql2008ClientDriver>();
db.ConnectionString = connectionString;
db.BatchSize = 1500;
db.LogSqlInConsole = false;
db.PrepareCommands = true;
db.ConnectionReleaseMode = ConnectionReleaseMode.AfterTransaction;
db.IsolationLevel = IsolationLevel.ReadCommitted;
})
.SetProperty(Environment.CurrentSessionContextClass, "web")
.SetProperty(Environment.UseSecondLevelCache, "true")
.SetProperty(Environment.ShowSql, "true")
.SetProperty(Environment.PrepareSql, "true")
.Cache(c =>
{
c.UseQueryCache = true;
c.Provider<RtMemoryCacheProvider>();
c.DefaultExpiration = 1440;
}).SessionFactory().GenerateStatistics();
HbmMapping mapping = GetMappings();
cfg.AddDeserializedMapping(mapping, "AppName");
SchemaMetadataUpdater.QuoteTableAndColumns(cfg);
return cfg.BuildSessionFactory();
}
private static HbmMapping GetMappings()
{
var mapper = new ModelMapper();
mapper.AddMappings(typeof (UserMap).Assembly.GetTypes());
HbmMapping mapping = mapper.CompileMappingForAllExplicitlyAddedEntities();
return mapping;
}
}
Here is a neat little bit for managing SignalR dependencies with Castle. You may want to give this a try just for giggles.
public class SignalRDependencyResolver : Microsoft.AspNet.SignalR.DefaultDependencyResolver
{
private readonly IWindsorContainer _container;
public SignalRDependencyResolver(IWindsorContainer container)
{
if (container == null)
{
throw new ArgumentNullException("container");
}
_container = container;
}
public override object GetService(Type serviceType)
{
return TryGet(serviceType) ?? base.GetService(serviceType);
}
public override IEnumerable<object> GetServices(Type serviceType)
{
return TryGetAll(serviceType).Concat(base.GetServices(serviceType));
}
[DebuggerStepThrough]
private object TryGet(Type serviceType)
{
try
{
return _container.Resolve(serviceType);
}
catch (Exception)
{
return null;
}
}
private IEnumerable<object> TryGetAll(Type serviceType)
{
try
{
Array array = _container.ResolveAll(serviceType);
return array.Cast<object>().ToList();
}
catch (Exception)
{
return null;
}
}
}
Put this in global asax before you set your controller factory
// SignalR
_container.Register(Classes.FromThisAssembly().BasedOn(typeof(IHub)).LifestyleTransient());
SignalRDependencyResolver signalRDependencyResolver = new SignalRDependencyResolver(_container);
Microsoft.AspNet.SignalR.GlobalHost.DependencyResolver = signalRDependencyResolver;

Nancy - Unable to resolve type: NHibernate.ISession

My CustomBootstrapper looks like below
public class CustomBootstrapper : DefaultNancyBootstrapper
{
protected override NancyInternalConfiguration InternalConfiguration
{
get
{
//This will tell Nancy it won't have to look in the Nhibernate assemblies for implementations of our interfaces.
return NancyInternalConfiguration
.Default
.WithIgnoredAssembly(asm => asm.FullName.StartsWith("NHibernate", StringComparison.InvariantCulture))
.WithIgnoredAssembly(asm => asm.FullName.StartsWith("Fluent", StringComparison.InvariantCulture))
.WithIgnoredAssembly(asm => asm.FullName.StartsWith("Iesi", StringComparison.InvariantCulture));
}
}
protected override void ConfigureRequestContainer(TinyIoCContainer container, NancyContext context)
{
base.ConfigureRequestContainer(container, context);
//container.Register((c, p) => SessionFactory.OpenSession());
container.Register(SessionFactory.OpenSession());
}
}
I have a repository which accepts ISession as a constructor dependency. When I run my application I get an error saying Unable to resolve type: NHibernate.ISession
I can confirm that
My bootstrapper is picked up by Nanacy
The ISession registration code is executed
I have tried commenting out .WithIgnoredAssembly(asm => asm.FullName.StartsWith("NHibernate", StringComparison.InvariantCulture)) from property InternalConfiguration
I get the error with both of the ways of registering component (one is commented in my code)
I have looked at similar other questions on SO and none has helped so far.
I've done a sample project that uses NH with Nancy. In the bootstrapper I set up:
a BeforeRequest hook that creates the session and binds it to the session context
a AfterRequest hook that commits the session
an OnError hook that rolls back
The code is as follows:
public class Bootstrapper : WindsorNancyBootstrapper
{
// other stuff
protected override void ApplicationStartup(IWindsorContainer container, IPipelines pipelines)
{
base.ApplicationStartup(container, pipelines);
// other setup
ConfigureNHibernateSessionPerRequest(container, pipelines);
}
private void ConfigureNHibernateSessionPerRequest(IWindsorContainer container, IPipelines pipelines)
{
pipelines.BeforeRequest += ctx => CreateSession(container);
pipelines.AfterRequest += ctx => CommitSession(container);
pipelines.OnError += (ctx, ex) => RollbackSession(container);
}
private Response RollbackSession(IWindsorContainer container)
{
var sessionFactory = container.Resolve<ISessionFactory>();
if (CurrentSessionContext.HasBind(sessionFactory))
{
var requestSession = sessionFactory.GetCurrentSession();
requestSession.Transaction.Rollback();
CurrentSessionContext.Unbind(sessionFactory);
requestSession.Dispose();
}
return null;
}
private Response CreateSession(IWindsorContainer container)
{
var sessionFactory = container.Resolve<ISessionFactory>();
var requestSession = sessionFactory.OpenSession();
CurrentSessionContext.Bind(requestSession);
requestSession.BeginTransaction();
return null;
}
private AfterPipeline CommitSession(IWindsorContainer container)
{
var sessionFactory = container.Resolve<ISessionFactory>();
if (CurrentSessionContext.HasBind(sessionFactory))
{
var requestSession = sessionFactory.GetCurrentSession();
requestSession.Transaction.Commit();
CurrentSessionContext.Unbind(sessionFactory);
requestSession.Dispose();
}
return null;
}
}

How to make this thread-safe

I have the following SessionFactory for Fluent NHibernate.
I am getting an error of
An invalid or incomplete configuration was used while creating a SessionFactory.
with an InnerException of
An item with the same key has already been added.
This problem is only happening occasionally and my application works fine most of the time.
Based on NHibernate: System.Argument Exception : An item with the same key has already been added I'm guessing my class is not thread-safe which would explain the intermittent nature of this error.
using System;
using NHibernate;
using NHibernate.Cache;
using NHibernate.Cfg;
using FluentNHibernate.Cfg;
using FluentNHibernate.Cfg.Db;
using WSS.Data.Domain;
namespace WSS.Data {
public static class SessionFactory {
private static ISessionFactory _factory = null;
private static ISessionFactory GetFactory() {
if (_factory == null) {
NHibernate.Cfg.Configuration config;
config = new NHibernate.Cfg.Configuration();
config.Configure();
if (config == null) {
throw new InvalidOperationException("NHibernate configuration is null.");
}
config.AddAssembly("WSS.Data");
_factory = config.BuildSessionFactory();
if (_factory == null) {
throw new InvalidOperationException("Call to Configuration.BuildSessionFactory() returned null.");
}
}
return _factory;
}
private static ISessionFactory GetFluentFactory() {
if(_factory == null) {
_factory = Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2000
.ConnectionString(c => c
.Is(ConnectionStrings.Auto))
.Cache(c => c
.UseQueryCache()
.ProviderClass())
.ShowSql())
.Mappings(m => m
.FluentMappings.AddFromAssemblyOf())
.BuildSessionFactory();
}
return _factory;
}
public static ISession OpenSession() {
ISession session;
session = GetFluentFactory().OpenSession();
if (session == null) {
throw new InvalidOperationException("Call to factory.OpenSession() returned null.");
}
return session;
}
}
}
The usual approach is to create a mutex (probably in your public method) that only allows single access. See http://msdn.microsoft.com/en-us/library/system.threading.mutex.aspx
Not tested as compiling, but something like:
private static Mutex _sessionMutex = new Mutex();
public static ISession OpenSession() {
ISession session;
_sessionMutex.WaitOne();
session = GetFluentFactory().OpenSession();
if (session == null) {
throw new InvalidOperationException("Call to factory.OpenSession() returned null.");
}
_sessionMutex.ReleaseMutex();
return session;
}

FluentNHibernate and Not Recognizing the Session

For some reason the Nhibernate is chocking out when I try to access the session. It is throwing the following exception:
No CurrentSessionContext configured (set the property current_session_context_class)!
Please note I am not using XML to setup the configuration!
I am opening the session in my test:
[SetUp]
public void Initialize()
{
_session = GetSessionFactory().OpenSession();
_transaction = _session.BeginTransaction();
SetupContext();
When();
}
and then I am using Repository to access the current session. The repository is in different dll.
public void Save(Category newCategory)
{
var session = SessionFactory.GetSession();
session.SaveOrUpdate(newCategory);
}
public static ISession GetSession()
{
var session = _sessionFactory.GetCurrentSession();
if (session == null)
return _sessionFactory.OpenSession();
return session;
}
UPDATE:
In my BaseTest.cs class I also have a teardown:
[TearDown]
public void CleanUp()
{
_session.Dispose();
_transaction.Dispose();
}
During debugging it seems like the CleanUp is being fired and killing the _session object!
Another update: I have added the following code when building the configuration:
public static ISessionFactory CreateSessionFactory()
{
_sessionFactory =
Fluently.Configure().Database(
MsSqlConfiguration.MsSql2000.ConnectionString(
c => c.FromConnectionStringWithKey("ConnectionString")))
.Mappings(m =>
m.FluentMappings.AddFromAssemblyOf<Category>())
**.ExposeConfiguration(x =>
{
x.SetProperty("current_session_context_class",
"thread_static");
})**
.BuildSessionFactory();
return _sessionFactory;
}
Now I get the following error:
No session bound to the current context
You need to bind the session to the current context.
In the setup method:
var session = SessionFactory.OpenSession();
CurrentSessionContext.Bind(session);
And in the teardown method:
var session = CurrentSessionContext.Unbind(SessionFactory);
session.Dispose();