Serialization issue

[Olivier-JOURDAN]

Hi there,

I'm comming across an issue using serialization feature of G#. I've read this post https://decibel.ni.com/content/thread/10293?tstart=0 and modify the attached demo project to reproduce the bug.

I've added one level of inheritance and an error 91 occurs at Variant To Data in MyTestClass.lvclass:Kernel.vi:2->MySubTestClass.lvclass:Kernel.vi:2->G#Object.lvclass:G#Object_Deserialize.vi:1->G# - SerializationExample.vi.

Are you aware of this issue ? If so have you a workaround ?

Thanks,

Olivier

[Fox_Mccloud]

Hello Olivier!

Nice to hear from you again and wonderful that you once again dig up some interesting implementation discussions!

Basically, from what I see and know, the binary serialization which supports aggregates, is only ment to be working on one class (actual code) to one exactly identical class. I.e creating a serialisation from a subsub-class to a sub-class (example) will result to a missmatch.

My guess is that Mattias just now is conjuring up some neat code to get this to work for you. In the mean time, I have thought up a way for you to cast the object to the parent class and then serialize it. When you reserialize it the class-types will match.

I hope this will help you out.

Sincerly,

Andreas Beckman

[Mattias_Ericsson]

Hi,

Andreas is absolutely correct. You are serializing a sub class and then trying to deserialize it as a more generic class, which will result in a type missmatch. I think this is a bit strange, since the serialization really prefers the same type for serialization and deserialization. However, it you want to perform a subclass serialization and the deserialize it as a more generic class, the code Andreas posted is the way to go. You have to convert the reference to a more generic class, matching the type you want to deserialize with. You could also use the "Convert to more generic" function where you could explicit point out the parent type you want. It is almost similiar to the example Andreas provided. I attach a modifed example where I use this instead.

Notice that "Convert to more generic" is not the same thing as "Cast to more generic" using LabVIEWs built in class casting. The convert to more generic will actually convert the reference to a more generic instance and not only the the type as cast will do. Dynamic dispatch will not work the same after a convert vs cast (which actually is the desired feature).

Thanks,

Mattias

[Olivier-JOURDAN]

Hello Andreas and Mattias,

That sounds good. Thank you for your quick support. The fix works great in my use case.

Regards,

Olivier