How to properly configure NHibernate event listeners

Question

I'm trying to use an event listener for the first time. All samples I've seen show how easy it is to configure, but for some reason I'm having trouble - it doesn't seem to be called. I suspect I'm missing something obvious.

I've tried this:

<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2">
    <session-factory name="TerraCognita.LoanExpress">
        <!-- other stuff... -->
        <listener type="delete" class="Test.TestDeleteListener, MyDllName" />
    </session-factory>
</hibernate-configuration>

as well as:

<hibernate-configuration   xmlns="urn:nhibernate-configuration-2.2">
    <session-factory name="TerraCognita.LoanExpress">
        <!-- other stuff... -->
        <event type="delete">
            <listener class="Test.TestDeleteListener, MyDllName" />
        </event>
    </session-factory>
</hibernate-configuration>

When configuration is loaded and the session factory is built:

var cfg = new NHibernate.Cfg.Configuration();
cfg.AddAssembly("MyDllName");
sessionFactory = cfg.BuildSessionFactory();

After instantiation, cfg.EventListeners.DeleteEventListeners has a single entry, of type DefaultDeleteEventListener (as I'd expect). However, after cfg.AddAssembly is called, this is still the case - but given the configuration, I would expect that the DeleteEventListener should actually be of type TestDeleteListener.

In my unit test, the only way I can get my event listener working is by manually adding it to the session info:

var sess = GetSession();
sess.GetSessionImplementation().Listeners.DeleteEventListeners = 
    new NHibernate.Event.IDeleteEventListener[] { new TestDeleteListener() };

I know this shouldn't be required, and I should be able to configure it properly. Can anyone shine a light on what I'm doing wrong here?

Answer 1

Your configuration is ok, it's just that you overlooked to call cfg.Configure(). Change your initialization code to this and your fine:

var cfg = new NHibernate.Cfg.Configuration();
cfg.Configure();
cfg.AddAssembly("MyDllName");
sessionFactory = cfg.BuildSessionFactory();