Hi,

I am experiencing a strange problem where the ASP.NET compiler seems to be looping when I try to use the NH session to get a domain object in the constructor of another domain object.

The page never loads and I can see multiple csc.exe processes get started and eventually the VS 2005 development web server crashes. It seems to be happening in the NH initialisation that normally occurs when you first fire up an application in debug.

I am wondering if NH instantiates each domain object during initialisation which results in a never ending loop of some kind because my constructor tries to load an object from the session which has not yet been initialised.

Should I be able to load an object in the constructor of another object or is this a big no-no!? I need to be able to initialise the Status property of my object when it is first created...is there another way to achieve this?

Thanks,

Jason

NHibernate instantiates an object of your class to find out the default value of its identifier which it then uses as unsaved-value. csc.exe may also be run by the reflection optimizer of NHibernate (if you're using NH 1.0.x or .NET 1.1).

I wouldn't do anything that requires access to the session in the constructor since the object may be constructed by NHibernate itself when the session is doing something and is not reentrant.

Cool...thanks for the response Sergey.

I figured that NH must have been doing something like that and have moved the status initialisation out of the constructor.

What is the best practice for implementing the initialisation of properties on a domain object where those properties reference other domain objects?

In my case the Status property should have an initial value of "Created" and then there are other methods that can trigger an update of the Status. I have moved the initial assignment of "Created" into my service layer but it feels like it should really be in the domain somewhere.

Thanks,

Jason

I don't understand why you need to access a session to assign the status? Why don't you just create a new Status object, or get it from a factory or whatever?

We have a Status object with the following properties:

ID
Description

We effectively have 12 pre-defined statuses that exist in the database and we just want to load one of them and assign it to the new domain object we are creating (many-to-one).

That is why I was using the Session to retrieve it in the constructor.

You can load the Status instance from the database at the beginning of your application, store it in some global variable, and have the domain object use that global one when it's created.