Generic Types In Flat Buffer

Question

I am having some trouble converting my games network communication from sending json to using flat buffers.

How my games client / server communication works: We have a base class called GameMessage

[Serializable]
public class GameMessage
{
    public abstract string TypeIdentifier { get; }
}

Then we have classes that inherit from GameMessage for each type of data manipulation

[Serializable]
public class CreateEntity : GameMessage
{
  public string typeIdentifier = "CreateEntity";
  public override string TypeIdentifier => typeIdentifier;
  public string EntityID;
}

[Serializable]
public class DeleteEntity : GameMessage
{
  public string typeIdentifier = "DeleteEntity";
  public override string TypeIdentifier => typeIdentifier;
  public string EntityID;
}

[Serializable]
public class ChangeAttribute: GameMessage
{
  public string typeIdentifier = "ChangeAttribute";
  public override string TypeIdentifier => typeIdentifier;
  public string EntityID;
  public AttributeData Attribute;
}

In the json deserialization code, we read from the TypeIdentifier parameter to identify the desired deserialization type. This allows the client to determine what type a message should be deserialized as, so in a nice way we can run handling behaviour based on the message type. This does not really work with flat buffers.

My question: Is there a good way using flat buffers to generally define a table (or type as its referred to in C#) so the client can handle the messages without any explicit type checking.

Answer 1

FlatBuffer's union feature is ideal to encode this kind of structure, and can do so without having to store or check identifier strings.