Hi
I'm kind of a new user in Nhibernate and I've ran into a problem considering serialization. The database I'm working on will produce in the end parents containing children etc (multileveled tree), therefore the need to use Lazy = true (we don't want to load half the database for a single information, if needed). The problem is that at some point I have to serialize a part of the tree... and from what I understood serialization with lazy loading would be impossible. Has anyone had this problem before and is there any workaround this?

I'm interested also on this idea...But in my opinion it's impossible ...

It should be possible, but you need to have the necessary libraries around when you deserialize the object. For example, serializing and deserializing in the same application works just fine.

I've done a little test (yes, in the same application), trying to serialize (XMLSerializer) a lazyLoading object that contains inner objects. The exception I got is

System.InvalidOperationException: There was an error generating the XML document. ---> System.InvalidOperationException: CProxyTypeMyNamespaceMyClass_NHibernate_ProxyINHibernateProxy_System_Runtime_SerializationISerializable2 cannot be serialized because it does not have a parameterless constructor.
at System.Xml.Serialization.TypeDesc.CheckSupported()
at System.Xml.Serialization.TypeScope.GetTypeDesc(Type type, MemberInfo source, Boolean directReference, Boolean throwOnError)
...

Trying to work with BinaryFormatter serializes ok, but throws an exception when deserializing

NHibernate.LazyInitializationException: Could not initialize proxy - no Session.
at NHibernate.Proxy.LazyInitializer.Initialize() in c:\net\nhibernate\nhibernate\src\NHibernate\Proxy\LazyInitializer.cs:line 77
at NHibernate.Proxy.LazyInitializer.GetImplementation() in c:\net\nhibernate\nhibernate\src\NHibernate\Proxy\LazyInitializer.cs:line 240
at NHibernate.Proxy.CastleLazyInitializer.Intercept(IInvocation invocation, Object[] args) in c:\net\nhibernate\nhibernate\src\NHibernate\Proxy\CastleLazyInitializer.cs:line 59
at CProxyTypeMyNamespaceMyClass_NHibernate_ProxyINHibernateProxy_System_Runtime_SerializationISerializable2.ToString()
...

As I said... I need a solution for lazyLoading (when lazy = false everything is fine, but the option is not acceptable)

Thx in advance,
Sirin

Ahh, XML serialization is an entirely different story. I assumed you meant standard .NET serialization. XML serialization has lots of limitations, not just proxies.

This may sound strange... but it's the client's idea and I had to ask: is there any way to programmatically change the lazy loading at runtime?

Technically, probably yes.
Practically, no.

I am having this same issue? Is there another solution for XML serialization that supports proxies?

I am having this same issue? Is there another solution for XML serialization that supports proxies?

@nolamonk (don't know if this helps.. but here it goes)
We're currently thinking about implementing the serialization ouselves... but one idea that came to us was to have 2 sessionFactory objects, one built from the normal config and the second one from a changed Configuration (modify the input stream to change all the lazy = true to lazy = false)...