Provide example for a .NET Core App serializing a session.

[ngbrown]

From the release notes on .Net Core 2.0 framework compatibility:

Binary serialization is not supported - the user shall implement serialization surrogates for System.Type,
FieldInfo, PropertyInfo, MethodInfo, ConstructorInfo, Delegate, etc.

This issue replaces the pull request #1425 as a direction was chosen to not provide in-the-library support for session serialization on the new frameworks. This is probably for the best as the pull-request was fairly invasive.

Application level support using serialization surrogates will be more elegant, but an example implementation, and tests, of those surrogates would certainly help.

If your scenario actually needs this support, and you want to migrate to dotnet, then this is the issue to vote on.

[hazzik]

@jrgcubano commented 18 April 2018 on #1425:

@ngbrown Hi. I do not know if it will give you any value, but on the FluentNHibernate side we have finished using serialization surrogates for our cloner

Thanks in advance for the amazing work guys!

[hazzik]

@ngbrown @fredericDelaporte I was playing with the serialization surrogates and got the resulting code very similar to the mentioned one.

I have a plan to include this code into NHibernate codebase. The temptation is to include the surrogates into the SerializationHelper class. However it is not used anywhere in the core at the moment, only in tests.

Alternative option is to move SerializationHelper class (+surrogates) to the tests project (and update the test code to use it instead of bare BinaryFormatter).

Also, there is a SerializableType which uses bare BinaryFormatter. If the surrogates end up in the main codebase, shall we use them in SerializableType?

[fredericDelaporte]

If the surrogates end up in the main codebase, shall we use them in SerializableType?

It looks to me as a minimal change.

But it would be better to add a way to provide a custom serialization logic to SerializableType, allowing the user to provide his own surrogates if needed, able of serializing things not needed by other NHibernate serializable objects.

I am for putting the surrogates in SerializationHelper and use it in the test project.

Now should it stay itself in NHibernate assembly or be moved into the test project? I think it should stay in NHibernate assembly, because likely most people needing serialization under .Net Core will not have anything to change to the default surrogates, so forcing them to duplicate the code from the test project would not make much sens.

About SerializableType, it could then be handled by using SerializationHelper if we add a way to give more surrogates into SerializationHelper. (Should it even allow overriding some surrogates?)
But maybe will this be an undue coupling: may a user desire different serialization logic for entities properties using SerializableType and for serializing other NHibernate objects (sessions)? He could then still use something else than SerializationHelper for serializing these other NHibernate objects, but that would likely lead him to duplicate it somehow.

[hazzik]

I don't see how it is possible to configure the SerializableType. Are we talking about the same? I'm talking about that one.

[fredericDelaporte]

Yes, the same. (I had already updated your message with another link to it.) It would be a system wide configuration, through a static property or method for supplying either a binary formatter factory or a surrogate selector factory.