Is it possible to deserialize by type discriminator?

[TheCGDF]

For example, in json we can do this:

using System.Text.Json.Serialization;

[JsonPolymorphic(TypeDiscriminatorPropertyName = "type")]
[JsonDerivedType(typeof(PlayerLevelUpEvent), typeDiscriminator: "PlayerLevelUp")]
[JsonDerivedType(typeof(SystemBroadcastEvent), typeDiscriminator: "SystemBroadcast")]
public abstract record GameEvent;

public record PlayerLevelUpEvent(uint player_id, byte new_level) : GameEvent;
public record SystemBroadcastEvent(string message) : GameEvent;

Then I can deserialize from this:

[
  {
    "type": "PlayerLevelUp", // every object has a "type"
    "player_id": 1001,
    "new_level": 5
  },
  {
    "type": "SystemBroadcast",
    "message": "Hello..."
  }
]

And handle this event:

public void HandleEvent(List<GameEvent> gameEvents) {
    foreach (var gamEvent in gamEvents) {
        switch (gameEvent) {
            case PlayerLevelUpEvent levelUp:
                Console.WriteLine($"Player {levelUp.player_id} Level Up {levelUp.new_level}");
                break;
                
            case SystemBroadcastEvent broadcast:
                Console.WriteLine($"Broadcast: {broadcast.message}");
                break;
        }
    }
}

[AArnott]

Yes. See the doc on union types.