Creation of properties from managed code

I have a class deriving from Actor, with a constructor that looks like:

public class Card : Actor {
    public Card(string name = null) : base(name) {
      // Set up mesh, material, register events
      AddTag("MyTag");
      SetInt("MeaningOfLife", 42);
      var meaningOfLife = 9001;
      var gotIt = GetInt("MeaningOfLife", ref meaningOfLife);
      Debug.AddOnScreenMessage(1, 3.0f, Color.Red, $"Meaning of life: {gotIt}; {meaningOfLife}");
    }
}

When I play in the editor, it outputs False; 9001 when I’d expect True; 42.

I’ve played around and moved the GetInt and SetInt calls all over, thinking perhaps it was an object lifetime issue, but I can’t seem to get this to ever print out my expectations. Currently I’m instantiating a Card in OnWorldPostBegin(). I’ve also tried GetBool and SetBool and those didn’t work either – I’m guessing this is broken for all of the method pairs.

The AddTag() call seems to work – I can see it when I inspect the Details pane with the Card actor selected.

Is this a bug or am I doing something wrong?

[nxrighthere]

Yes, the only option is to use workarounds with object IDs, at the moment, since properties is the only intermediate type-safe data storage.

It seems that now we have Data Registries which can be used as an intermediate type-safe data storage. It’s introduced in Unreal Engine 5 and 4.27.0, so I’m going to investigate it.

[OlsonDev]

Thank you! I just figured that out on my own. 😃

Is this the recommended way to maintain state on a subclassed Actor? I’d rather not make Blueprint classes that are just property bags, if you will. It doesn’t feel like the native C# way of doing things.

For example, I handle OnActorBeginCursorOver(ActorReference actor) and I do actor.ToActor<Card>().SomeProperty and SomeProperty is reset to its default value because you’re calling FormatterServices.GetUninitializedObject(...), and thus the instance you give me isn’t the same one as I originally instantiated. Do I need to maintain a… dictionary of objects by ID and then take the actor you give me and then just look it up and use that? Or should I actually create blueprint instances for each object and dynamically look up/set properties in C++ land each time?