Serializing and deserializing unknown inherited types

Question

I started looking at using proto-buf .Net for my serialization needs for media browser.

In the new system we have a entity framework that can be extended with plug-ins.

So, for example, we define a Media class in the core library, and then plug-ins can define subclasses such as Song.

It seems that proto-buf .Net needs to know about all sub types of our core defined base class.

So I am expected to decorate my base class with

[ProtoInclude(2, typeof(Song))]

But ... at that point in time I know nothing about the Song class that does not exist yet.

Is it back to the drawing board? Am I trying to do something the library is not designed for?

Answer 1

(from the author)

In the current release, it is fixed to types known to the parent. However, this is a known limitation, so there is a plan to abstract the meta-model so that it can be provided separately at runtime - broadly comparable to how you provide such information to XmlSerializer (it will still need a way to provide tags (the "2" above) per type).

I have started on this work, but I expect it to take a few weeks to get it fully working (the refactor will also tie into some other changes to help compact framework).

So up to you... if you can wait a few weeks, I hope to have something working.

Note that you would still need some way of generating (unique, repeatable) tags for all the different sub-types - configuration, etc.