Question

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?

Answer 1

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();
        }
    }
}