NHibernate not persisting changes to my object

Question

My ASP.NET MVC 4 project is using NHibernate (behind repositories) and Castle Windsor, using the AutoTx and NHibernate Facilities. I've followed the guide written by haf and my I can create and read objects.

My PersistenceInstaller looks like this

public class PersistenceInstaller : IWindsorInstaller
{
    public void Install(Castle.Windsor.IWindsorContainer container, Castle.MicroKernel.SubSystems.Configuration.IConfigurationStore store)
    {
        container.AddFacility<AutoTxFacility>();            
        container.Register(Component.For<INHibernateInstaller>().ImplementedBy<NHibernateInstaller>().LifeStyle.Singleton);
        container.AddFacility<NHibernateFacility>(
            f => f.DefaultLifeStyle = DefaultSessionLifeStyleOption.SessionPerWebRequest);          
    }
}

The NHibernateInstaller is straight from the NHib Facility Quickstart.

I am using ISessionManager in my base repository...

protected ISession Session
{
    get
    {
        return _sessionManager.OpenSession();
    }
}

public virtual T Commit(T entity)
{
    Session.SaveOrUpdate(entity);            
    return entity;
}

Finally, my application code which is causing the problem:

[HttpPost]
[ValidateAntiForgeryToken]        
[Transaction]
public ActionResult Maintain(PrescriberMaintainViewModel viewModel)
{           
    if (ModelState.IsValid)
    {
        var prescriber = UserRepository.GetPrescriber(User.Identity.Name);

        //var prescriber = new Prescriber { DateJoined = DateTime.Today, Username = "Test" };                
        prescriber.SecurityQuestion = viewModel.SecurityQuestion;
        prescriber.SecurityAnswer = viewModel.SecurityAnswer;
        prescriber.EmailAddress = viewModel.Email;
        prescriber.FirstName = viewModel.FirstName;
        prescriber.LastName = viewModel.LastName;
        prescriber.Address = new Address
                                {
                                    Address1 = viewModel.AddressLine1,
                                    Address2 = viewModel.AddressLine2,
                                    Address3 = viewModel.AddressLine3,
                                    Suburb = viewModel.Suburb,
                                    State = viewModel.State,
                                    Postcode = viewModel.Postcode,
                                    Country = string.Empty
                                };

        prescriber.MobileNumber = viewModel.MobileNumber;
        prescriber.PhoneNumber = viewModel.PhoneNumber;
        prescriber.DateOfBirth = viewModel.DateOfBirth;
        prescriber.AHPRANumber = viewModel.AhpraNumber;
        prescriber.ClinicName = viewModel.ClinicName;
        prescriber.ClinicWebUrl = viewModel.ClinicWebUrl;
        prescriber.Qualifications = viewModel.Qualifications;
        prescriber.JobTitle = viewModel.JobTitle;


        UserRepository.Commit(prescriber);          
    }

    return View(viewModel);
}

The above code will save a new prescriber (tested by uncommenting out the commented out line etc).

I am using NHProf and have confirmed that no sql is sent to the database for the Update. I can see the read being performed but that's it.

It seems to me that NHibernate doesn't recognise the entity as being changed and therefore does not generate the sql. Or possibly the transaction isn't being committed?

I've been scouring the webs for a few hours now trying to work this one out and as a last act of desperation have posted on SO. Any ideas? :)

Oh and in NHProf I see three Sessions (1 for the GetPrescriber call from the repo, one I assume for the update (with no sql) - and one for some action in my actionfilter on the base class). I also get an alert about the use of implicit transactions. This confuses me because I thought I was doing everything I needed to get an transaction - using AutoTx and the Transaction attribute. I also expected there to be only 1 session per webrequest, as per my Windsor config.

UPDATE: It seems, after spending the day reading through the source for NHibernateFacility and AutoTx Facility for automatic transactions, that AutoTx is not setting the Interceptors on my implementation of INHibernateInstaller. It seems this means whenever SessionManager calls OpenSession it is calling the default version with no parameter, rather than the one that accepts an Interceptor. Internally AutoTxFacility registers TransactionInterceptor with windsor, so that it can be added the Interceptor on my INHibernateInstaller concrete, by windsor making use of the AutoTx's TransactionalComponentInspector

AutoTxFacility source on github

Answer 1

After spending a full day yesterday searching through the AutoTx and NHibernate facilities on github and getting nowhere, I started a clean project in an attempt to replicate the problem. Unfortunately for the replication, everything worked! I ran Update-Package on my source and brought down new version of Castle.Transactions and I was running correctly. I did make a small adjustment to my own code. That was to remove the UserRepository.Commit line.

I did not need to modify how I opened sessions. That was taken care of by the SessionManager instance. With the update to Castle.Transactions, the Transaction attribute is being recognised and a transaction is being created (as evidenced by no more alert in NHProf).

Answer 2

To me it looks like creating sessions for every call to the repository. A session should span the whole business operation. It should be opened at the beginning and committed and disposed at the end.

There are other strange things in this code.

• Commit is a completely different concept than SaveOrUpdate.
• And you don't need to tell NH to store changes anyway. You don't need to call session.Save for objects that are already in the session. They are stored anyway. You only need to call session.Save when you add new objects.
• Make sure that you use a transaction for the whole business operation.

Answer 3

There is one most likely "unintended" part in the code snippet above. And proven by observation made by NHProf

Oh and in NHProf I see three Sessions (1 for the GetPrescriber call from the repo, one I assume for the update (with no sql) - and one for some action in my actionfilter on the base class).

Calling the OpenSession() is triggering creation of a new session instances.

protected ISession Session
{
    get { return _sessionManager.OpenSession(); }
}

So, whenever the code is accessing the Session property, behind is new session instance created (again and again). One session for get, one for udpate, one for filter...

As we can see here, the session returned by SessionManager.OpenSession() must be used for the whole scope (Unit of work, web request...)

http://docs.castleproject.org/Windsor.NHibernate-Facility.ashx

The syntaxh which we need, si to create one session (when firstly accessed) and reuse it until enf of scope (then later correctly close it, commit or rollback transaction...). Anyhow, first thing right now is to change the Session property this way:

ISession _session;
protected ISession Session
{
    get 
    { 
      if (_session == null)
      {
         _session = sessionFactory.OpenSession();
      }
      return _session; 
    }
}