How implement the Open Session in View pattern in NHibernate?
I'm using ASP.NET MVC + NHibernate + Fluent NHibernate and having a problem with lazy loading.
Through this question (How to fix a NHibernate lazy loading error "no session or session was closed"?), I've discovered that I have to implement the Open Session in View pattern , but I don't know how.
In my repositories classes, I use methods like this
public ImageGallery GetById(int id) {
using(ISession session = NHibernateSessionFactory.OpenSession()) {
return session.Get<ImageGallery>(id);
}
}
public void Add(ImageGallery imageGallery) {
using(ISession session = NHibernateSessionFactory.OpenSession()) {
using(ITransaction transaction = session.BeginTransaction()) {
session.Save(imageGallery);
transaction.Commit();
}
}
}
And this is my Session Factory helper class:
public class NHibernateSessionFactory {
private static ISessionFactory _sessionFactory;
private static ISessionFactory SessionFactory {
get {
if(_sessionFactory == null) {
_sessionFactory = Fluently.Configure()
.Database(MySQLConfiguration.Standard.ConnectionString(MyConnString))
.Mappings(m => m.FluentMappings.AddFromAssemblyOf<ImageGalleryMap>())
.ExposeConfiguration(c => c.Properties.Add("hbm2ddl.keywords", "none"))
.BuildSessionFactory();
}
return _sessionFactory;
}
}
public static ISession OpenSession() {
return SessionFactory.OpenSession();
}
}
Someone could help me to implements Open开发者_运维技巧 Session in View pattern?
Thank you.
This is already asked before, but I don't remember where to find it. When you do the following or something similar, you have what you want and some code duplication reduce in your repositories as bonus.
- Use this (code from question modified with the answer) in global.asax: Application_EndRequest Doesn't Fire on a 404
- Use the same session and transaction instance for every method executed during a web-request.
public class Repository
{
private readonly ISession session;
public Repository()
{
session = CurrentSessionContext.CurrentSession();
}
public ImageGallery GetById(int id)
{
return session.Get<ImageGallery>(id);
}
public void Add(ImageGallery imageGallery)
{
session.Save(imageGallery);
}
}
You can also manage the session with an ioc container and a unit of work wrapper instead of the current session context.
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