Cannot set entity properties in NHibernate event listener.

Question

Hi all

I'm overriding NHibernate's PreInsertEventListener in order to set the entity's DateCreated property to DateTime.Now.

Here is my code:

public bool OnPreInsert(PreInsertEvent e)
{
  DomainObject domainObject = (DomainObject) e.Entity;
  if (domainObject.CreatedById == 0) throw new Exception("The " + domainObject.GetType().Name + " cannot be created if its CreatedById property has not been set.");
  domainObject.DateCreated = DateTime.Now;
  return false;
}

I am finding that any entity properties set here (for example, the call to DateCreated above) do not find their way into the update SQL created by NHibernate. Does anyone know what gives?

Yes, I have cofirmed that my event listener is being called!

Thanks

David

Answer 1

Hmmm, it seems you have to use a specific syntax to modify the entity's properties at this stage of the game.

That syntax is demonstrated here:

http://stackoverflow.com/questions/2365750/why-both-nhibernate-onpreinsert-and-onpreupdate-methods-get-called-for-an-object

Note that I've discovered you don't also have to set the entity's properties the normal way as well, which this code does.

Thanks

David