Transaction auto-wrapping for the data access layer

In this recipe, we'll show you how to set up the data access layer to wrap all data access in NHibernate transactions automatically.

Getting ready

Complete the Eg.Core model and mappings from Chapter 2, Models and Mappings.

How to do it…

1. Create a new class library named Eg.Core.Data.

2. Install NHibernate to Eg.Core.Data using the NuGet Package Manager Console.

3. Add the following two DataAccessObject classes:

   public class DataAccessObject<T, TId>
     where T : Entity<TId>
   {
   
     private readonly ISessionFactory _sessionFactory;
   
     private ISession session
     {
       get
       {
         return _sessionFactory.GetCurrentSession();
       }
     }
   
     public DataAccessObject(ISessionFactory sessionFactory)
     {
       _sessionFactory = sessionFactory;
     }
   
     public T Get(TId id)
     {
       return WithinTransaction(() => session.Get<T>(id));
     }
   
     public T Load(TId id)
     {
       return WithinTransaction(() => session.Load<T>(id));
     }
   
     public void...