I am trying to use fluent with session per request. I am following a "recipe" from nhibernate cookbook however it uses the nhibernate config file.
I am not sure what is better but right now I am sticking with fluent config just because I would not know how to set the nhibernate config file to use fluent mapping and vanilla nhibernate mapping(hbm files).
namespace Demo.WebUI
{
public class MvcApplication : NinjectHttpApplication
{
public static ISessionFactory SessionFactory { get; private set; }
protected override void OnApplicationStarted()
{
SessionFactory = Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2008.ConnectionString(
c => c.FromConnectionStringWithKey("test")))
.Mappings(m => m.FluentMappings
.AddFromAssemblyOf
<Demo.Framework.Data.NhibernateMapping.UserMap>())
.ExposeConfiguration(BuidSchema)
.BuildSessionFactory();
}
protected void Application_BeginRequest(object sender, EventArgs e)
{
var session = SessionFactory.OpenSession();
//CurrentSessionContext.Bind(session);
}
protected void Application_EndRequest(object sender, EventArgs e)
{
//var session = CurrentSessionContext.Unbind(SessionFactory);
SessionFactory.Dispose();
}
}
}
As you can see in the Begin_Request the books tutorial had
CurrentSessionContext.Bind(session);
However if I use this it throws a error since I don't have the nhibernate config file in use.
So how do I change it to use fluent configuration? Or do I not even need to do this step?(ie is it done internally?)
You need to tell NHibernate how to handle the session context. The following might work:
Fluently.Configure()
...
.ExposeConfiguration(cfg => cfg.SetProperty(
Environment.CurrentSessionContextClass,
"web")
Also, unrelated to this: you are disposing the SessionFactory on EndRequest. That is an error.
If your project is Asp.Net web site (not web application ), in Global.asax you should use like that
NHibernate.Cfg.Environment.CurrentSessionContextClass
Related
I keep getting the following message while retrieving my domain objects:
failed to lazily initialize a collection of role no session or session was closed
I know the problem has something to do with lazy loading of the collection on my domain object and i'm trying to fix this, but it would be nice if someone could point me in the right direction. The problem is that i have a using statement on my session object and i would like to get rid of the sessions in my repository classes.
Stefan Steinegger recommended to use a TransactionService wich manages the transactions in the following post:
C# Shared Transactions and NHibernate using IRepository
It would be nice someone can provide a tutorial, example on how to implement such a service.
There's a few different ways that you can handle this within a web application and probably the most common in web applications is a Session Per Web Request.
Inside of Application_Start in global.asax.cs, create the SessionFactory and assign it to a static property:
public static ISessionFactory SessionFactory { get; private set; }
protected void Application_Start(object sender, EventArgs e)
{
// your configuration setup
var configuration = new NHibernate.Cfg.Configuration().Configure();
SessionFactory = configuration.BuildSessionFactory();
}
Then, in Application_BeginRequest in global.asax.cs, open a session using the SessionFactory and bind it to the CurrentSessionContext
protected void Application_BeginRequest(object sender, EventArgs e)
{
var session = SessionFactory.OpenSession();
CurrentSessionContext.Bind(session);
}
and in Application_EndRequest in global.asax.cs, unbind the session and dispose of it
protected void Application_EndRequest(object sender, EventArgs e)
{
var session = CurrentSessionContext.Unbind(SessionFactory);
session.Dispose();
}
Now inside of the application, whenever a session is required, we simply ask the SessionFactory for the current session
public class HomeController : Controller
{
public ActionResult Index()
{
IEnumerable<Product> products = null;
var session = MvcApplication.SessionFactory.GetCurrentSession();
using (var transaction = session.BeginTransaction())
{
// your query, which sounds like it should also eager load
// a child collection
products = session.QueryOver<Product>().List();
transaction.Commit();
}
return View(products);
}
}
There are numerous variations on this, including using a LazySessionContext to lazily create a session only if one is needed for a request, and implementations where ISessionFactory could be injected into you controllers through dependency injection.
I am reading nhibernate cookbook 3.0 and the fluent tutorial and I am kinda confused which one I should be using(cookbook by itself has many different ways)
Fluent Nhibernate tutorial
private static ISessionFactory CreateSessionFactory()
{
return Fluently.Configure()
.Database(
SQLiteConfiguration.Standard
.UsingFile("firstProject.db")
)
.Mappings(m =>
m.FluentMappings.AddFromAssemblyOf<Program>())
.ExposeConfiguration(BuildSchema)
.BuildSessionFactory();
}
private static void BuildSchema(Configuration config)
{
// delete the existing db on each run
if (File.Exists(DbFile))
File.Delete(DbFile);
// this NHibernate tool takes a configuration (with mapping info in)
// and exports a database schema from it
new SchemaExport(config)
.Create(false, true);
}
cookbook 3.0 pg(76) web request
1. In the hibernate-configuration section of web.config, add the current_
session_context_class property with a value of web.
2. If it doesn't exist already, add a new Global application class (Global.asax).
3. In Global.asax, add these using statements.
using NHibernate;
using NHibernate.Cfg;
using NHibernate.Context;
4. Create a static property named SessionFactory.
public static ISessionFactory SessionFactory { get;
private set; }
5. In the Application_Start method, add the following code.
protected void Application_Start(object sender, EventArgs e)
{
log4net.Config.XmlConfigurator.Configure();
var nhConfig = new Configuration().Configure();
SessionFactory = nhConfig.BuildSessionFactory();
}
6. In the Application_BeginRequest method, add the following code.
protected void Application_BeginRequest(object sender, EventArgs e)
{
var session = SessionFactory.OpenSession();
CurrentSessionContext.Bind(session);
}
7. In the Application_EndRequest method, add the following code:
protected void Application_EndRequest(object sender, EventArgs e)
{
var session = CurrentSessionContext.Unbind(SessionFactory);
session.Dispose();
}
Then they just use this to run it.
Guid productId = new Guid(Request["id"]);
Eg.Core.Product product;
var session = Global.SessionFactory.GetCurrentSession();
using (var tran = session.BeginTransaction())
{
product = session.Get<Eg.Core.Product>(productId);
tran.Commit();
}
Page.Title = product.Name;
Label1.Text = product.Name;
Label2.Text = product.Description;
With the fluent tutorial I am also kinda confused where I would typically put that code in an asp.net mvc application. I am trying to use the repository pattern with ninject(DI injection).
So with both ways I am not sure how to make it work with ninject and the repository pattern.
Is either way better for the repository pattern and Di?
Did you try to download the whole solution to run the project? These are just samples of code and you need the whole setup: VS project with Entity classes, mappings, repositories etc.
I would go to http://www.sharparchitecture.net/ and https://github.com/sharparchitecture download their Northwind sample project that has the exact setup that you need. You will have to find the Northwind database and install it on you local machine then modify the NHibernate.config to point to your database.
Edit
I would like to try to do what Remo Gloor has recommended
Create a SessionFactoryProvider derived for Provider that retruns a SessionFactory using the code in OnApplicationStarted
Create a binding for SessionFactory using the new provider and put it in SingletonScope
Create a SessionProvider derived from Provider that gets the SessionFactory injected in the constructor and retuns a new session using GetCurrentSession of the factory.
Create a binding for ISession to the above provider with activation and deactivation actions that open, transmit, rollback, and close the session (basiclly the code from Application_BeginRequest, EndRequest). Decalre the binding as in request scope.
Remove Application_BeginRequest, EndRequest.
Bind the repo using Bind().To();
I am looking for a tutorial that hits on these points with a file that I can download and play around with. If it uses lots of generics you needs to be pretty detailed as generics still get me.
Hi
I am trying to do session per request with my nhibernate.
I done this in my global.aspx
using System;
using System.Web.Mvc;
using System.Web.Routing;
using Demo.WebUI.Models.NinjectModules;
using FluentNHibernate.Cfg;
using FluentNHibernate.Cfg.Db;
using NHibernate;
using NHibernate.Context;
using Ninject;
using Ninject.Modules;
using Ninject.Web.Mvc;
namespace Demo.WebUI
{
// Note: For instructions on enabling IIS6 or IIS7 classic mode,
// visit http://go.microsoft.com/?LinkId=9394801
public class MvcApplication : NinjectHttpApplication
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/{id}", // URL with parameters
new {controller = "Account", action = "Login", id = UrlParameter.Optional} // Parameter defaults
);
}
public static ISessionFactory SessionFactory { get; private set; }
protected override void OnApplicationStarted()
{
AreaRegistration.RegisterAllAreas();
RegisterRoutes(RouteTable.Routes);
SessionFactory = Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2008.ConnectionString(c => c.FromConnectionStringWithKey("test")))
.Mappings(m => m.FluentMappings.AddFromAssemblyOf<Demo.Framework.Data.NhibernateMapping.UserMap>())
.ExposeConfiguration(x => x.SetProperty("current_session_context_class", "web"))
.ExposeConfiguration(BuidSchema)
.BuildSessionFactory();
}
protected void Application_BeginRequest(object sender, EventArgs e)
{
ISession session = SessionFactory.OpenSession();
session.BeginTransaction();
CurrentSessionContext.Bind(session);
}
protected void Application_EndRequest(object sender, EventArgs e)
{
ISession session = CurrentSessionContext.Unbind(SessionFactory);
if (session != null)
{
try
{
session.Transaction.Commit();
}
catch (Exception)
{
session.Transaction.Rollback();
}
finally
{
session.Close();
session.Dispose();
}
}
}
protected override IKernel CreateKernel()
{
var modules = new INinjectModule[]
{
new ServiceModule(),
new RepoModule()
};
return new StandardKernel(modules);
}
private static void BuidSchema(NHibernate.Cfg.Configuration config)
{
new NHibernate.Tool.hbm2ddl.SchemaExport(config).Create(false, true);
}
}
}
In my RepoModule I have
Bind<IUserRepo>().To<UserRepo>().WithConstructorArgument("session",MvcApplication.SessionFactory.GetCurrentSession());
This will throw a error because ninject will create the kernal before OnApplicationStarted() gets started and before Application_Begin starts to bind it.
So what should I do?
Edit
This is what I found in some tutorial.
public static ISessionFactory SessionFactory { get; private set; }
public MvcApplication()
{
SessionFactory = CreateSessionFactory();
}
private static ISessionFactory CreateSessionFactory()
{
return Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2008.ConnectionString(c => c.FromConnectionStringWithKey("test")))
.Mappings(m => m.FluentMappings.AddFromAssemblyOf<Demo.Framework.Data.NhibernateMapping.UserMap>())
.ExposeConfiguration(x => x.SetProperty("current_session_context_class", "web"))
.ExposeConfiguration(BuidSchema)
.BuildSessionFactory();
}
My binding
Bind<IUserRepo>().To<UserRepo>();
Bind<ISession>().ToMethod(x => MvcApplication.SessionFactory.GetCurrentSession());
So I first create the session factory on constructor load then I bind it to the Isession instead of passing it in as a parameter.
The only thing that I am not sure with the global aspx is if it will keep calling the constructor up everytime and recreating the SessionFactory what is bad. So I am not sure if I need to check if it exists first.
Your implementation is fine but not a good solution as you do manual control of the session lifecycle. The actual way this should be done is to let Ninject decide when the session is created, opened, closed and disposed.
E.g. imagine actions where you don't need any session. Or a larger project where you have several databases and sessions to split the load. In these situations you don't want all the possible sessions be created for each action as this means an avoidable overhead. You rather want that only those are created that are required for the current action.
To do so several changes are required:
Create a SessionFactoryProvider derived for Provider that retruns a SessionFactory using the code in OnApplicationStarted
Create a binding for SessionFactory using the new provider and put it in SingletonScope
Create a SessionProvider derived from Provider that gets the SessionFactory injected in the constructor and retuns a new session using GetCurrentSession of the factory.
Create a binding for ISession to the above provider with activation and deactivation actions that open, transmit, rollback, and close the session (basiclly the code from Application_BeginRequest, EndRequest). Decalre the binding as in request scope.
Remove Application_BeginRequest, EndRequest.
Bind the repo using Bind<IUserRepo>().To<UserRepo>();
I recently blogged about using nhibernate in an asp.net mvc application with a repository pattern. This project provides an example of using nhibernate & ninject. Here are a few links:
http://blog.bobcravens.com/2010/07/using-nhibernate-in-asp-net-mvc/
http://blog.bobcravens.com/2010/06/the-repository-pattern-with-linq-to-fluent-nhibernate-and-mysql/
http://blog.bobcravens.com/2010/09/the-repository-pattern-part-2/
http://blog.bobcravens.com/2010/11/using-ninject-to-manage-critical-resources/
I think that we have a similar architecture. Take a look at the posts and let me know if you have any questions.
BTW, you can download this project at http://gpsnerd.codeplex.com
Bob
Wrap the SessionFactory initialization code in a singleton, that will initialize and configure the sessionfactory once when you access the "Instance" property on it. Use this in BeginRequest instead of current code.
You're using a current session context, you don't have to inject the session!
Inject the SessionFactory instead, then use GetCurrentSession() to obtain an ISession.
After that change, you can use Felice's solution.
I have an identity mapping like so:
Id(x => x.GuidId).Column("GuidId")
.GeneratedBy.GuidComb().UnsavedValue(Guid.Empty);
When I retrieve an object from the database, the GuidId property of my object is Guid.Empty, not the actual Guid (the property in the class is of type System.Guid). However, all of the other properties in the object are populated just fine.
The database field's data type (SQL Server 2005) is uniqueidentifier, and marked as RowGuid.
The application that is connecting to the database is a VB.NET Web Site project (not a "Web Application" or "MVC Web Application" - just a regular "Web Site" project). I open the NHibernate session through a custom HttpModule. Here is the HttpModule:
public class NHibernateModule : System.Web.IHttpModule
{
public static ISessionFactory SessionFactory;
public static ISession Session;
private static FluentConfiguration Configuration;
static NHibernateModule() {
if (Configuration == null) {
string connectionString = cfg.ConfigurationManager.ConnectionStrings["myDatabase"].ConnectionString;
Configuration = Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2005.ConnectionString(cs => cs.Is(connectionString)))
.ExposeConfiguration(c => c.Properties.Add("current_session_context_class", "web"))
.Mappings(x => x.FluentMappings.AddFromAssemblyOf<LeadMap>().ExportTo("C:\\Mappings"));
}
SessionFactory = Configuration.BuildSessionFactory();
}
public void Init(HttpApplication context) {
context.BeginRequest += delegate {
Session = SessionFactory.OpenSession();
CurrentSessionContext.Bind(Session);
};
context.EndRequest += delegate {
CurrentSessionContext.Unbind(SessionFactory);
};
}
public void Dispose() {
Session.Dispose();
}
}
The strangest part of all, is that from my unit test project, the GuidId property is returned as I would expect. I even rigged it to go for the exact row in the exact database as the web site was hitting. The only differences I can think of between the two projects are
The unit test project is in C#
Something with the way the session is managed between the HttpModule and my unit tests
The configuration for the unit tests is as follows:
Fluently.Configure()
.Database(MsSqlConfiguration.MsSql2005.ConnectionString(cs => cs.Is(connectionString)))
.Mappings(x => x.FluentMappings.AddFromAssemblyOf<LeadDetailMap>());
I am fresh out of ideas. Any help would be greatly appreciated.
Thanks
I had a similar problem when in the mapping attribute Name was not set. You can try to save your fluent mappings into Xmls and check them.
So I really like working with NHibernate but always used Spring.Net with it.
I recently came across StructureMap by Jeremy Miller and really like it better than Spring.Net. On his StructureMap site he promises an example on how to use NHibernate and StructureMap together. Unfortunately he has not had time to do it (or I can't find it).
So does anyone have an example on how to handle the NHibernate Session with StructureMap?
So, I apologize that we did not get the NHibernate with StructureMap example done earlier. Eventually, I would like to publish it in the StructureMap documentation, but I need some feedback first. You can see the full example on my blog:
http://trason.net/journal/2009/10/7/bootstrapping-nhibernate-with-structuremap.html
That being said, I can hit the highlights here. There is an NHibernateRegistry that makes available four things: an NHibernate.Configuration (as a Singleton), an ISessionFactory (as a Singleton), an ISession (scoped Hybrid (HttpContext if available, falling back to Thread local storage)), and a very simple IUnitOfWork. Also, there is an HttpModule to manage the UnitOfWork per web request.
Here is the code for the NHibernateRegistry:
using NHibernate;
using NHibernate.ByteCode.Castle;
using NHibernate.Cfg;
using NHibernate.Dialect;
using NHibernate.Driver;
using NHibernateBootstrap.Core.Domain;
using StructureMap.Attributes;
using StructureMap.Configuration.DSL;
using Environment=NHibernate.Cfg.Environment;
namespace NHibernateBootstrap.Core.Persistence
{
public class NHibernateRegistry : Registry
{
public NHibernateRegistry()
{
var cfg = new Configuration()
.SetProperty(Environment.ReleaseConnections, "on_close")
.SetProperty(Environment.Dialect, typeof(SQLiteDialect).AssemblyQualifiedName)
.SetProperty(Environment.ConnectionDriver, typeof(SQLite20Driver).AssemblyQualifiedName)
.SetProperty(Environment.ConnectionString, "data source=bootstrap.sqlite;Version=3")
.SetProperty(Environment.ProxyFactoryFactoryClass, typeof(ProxyFactoryFactory).AssemblyQualifiedName)
.AddAssembly(typeof(Blog).Assembly);
var sessionFactory = cfg.BuildSessionFactory();
ForRequestedType<Configuration>().AsSingletons().TheDefault.IsThis(cfg);
ForRequestedType<ISessionFactory>().AsSingletons()
.TheDefault.IsThis(sessionFactory);
ForRequestedType<ISession>().CacheBy(InstanceScope.Hybrid)
.TheDefault.Is.ConstructedBy(ctx => ctx.GetInstance<ISessionFactory>().OpenSession());
ForRequestedType<IUnitOfWork>().CacheBy(InstanceScope.Hybrid)
.TheDefaultIsConcreteType<UnitOfWork>();
ForRequestedType<IDatabaseBuilder>().TheDefaultIsConcreteType<DatabaseBuilder>();
}
}
}
Here is the code for the Unit of Work:
using System;
using NHibernate;
namespace NHibernateBootstrap.Core.Persistence
{
public interface IUnitOfWork : IDisposable
{
ISession CurrentSession { get; }
void Commit();
}
}
using NHibernate;
namespace NHibernateBootstrap.Core.Persistence
{
public class UnitOfWork : IUnitOfWork
{
private readonly ISessionFactory _sessionFactory;
private readonly ITransaction _transaction;
public UnitOfWork(ISessionFactory sessionFactory)
{
_sessionFactory = sessionFactory;
CurrentSession = _sessionFactory.OpenSession();
_transaction = CurrentSession.BeginTransaction();
}
public ISession CurrentSession { get; private set;}
public void Dispose()
{
CurrentSession.Close();
CurrentSession = null;
}
public void Commit()
{
_transaction.Commit();
}
}
}
Here is the NHibernateModule for web applications:
using System;
using System.Web;
using NHibernateBootstrap.Core.Persistence;
using StructureMap;
namespace NHibernateBootstrap.Web
{
public class NHibernateModule : IHttpModule
{
private IUnitOfWork _unitOfWork;
public void Init(HttpApplication context)
{
context.BeginRequest += ContextBeginRequest;
context.EndRequest += ContextEndRequest;
}
private void ContextBeginRequest(object sender, EventArgs e)
{
_unitOfWork = ObjectFactory.GetInstance<IUnitOfWork>();
}
private void ContextEndRequest(object sender, EventArgs e)
{
Dispose();
}
public void Dispose()
{
_unitOfWork.Dispose();
}
}
}
Does this help: http://devlicio.us/blogs/billy_mccafferty/archive/2007/02/05/inject-di-container-into-domain-objects-with-nhibernate.aspx
Edit here: I posted this comment before wbinford's answer was posted. I still think using NCommon is good, but his answer above is a little cleaner and does not require the use of another third party tool.
I really didn't get the answers I was looking for but I found a nice framework called NCommon. It implements the unit of work pattern along with the repository pattern with NHibernate, LinqToSql or the Entity Framework. It also handled the NHibernate ISession as well as configuration for NHibernate. I used the tool with StructureMap and NHibernate. I did have to get the service adapter for StructureMap, but once set up it works rather nicely.