I’m playing around with Resources and trying to figure out a way to:
1. Prevent recursion errors when Resources store references to each other
I want Resources for GameStates and I would like to be able to reference other GameStates in them. For example, I want GameStates to know which other GameState to transition to when the escape button is pressed. However, this error appears when I set two GameStates to transition back and forth when the escape button is pressed:
Recursion detected, unable to assign resource to property.
Example code:
class_name GameState extends Resource
@export var escape_state: GameState
2. Store references to scenes in Resources without loading the scene automatically
It’s my understanding that having a property for a PackedScene in a Resource will automatically load the scene whenever the Resource is loaded. This is not ideal, as I would like to have a Resource for each game level and I don’t want the levels to load until the player switches to that level.
Example code:
class_name GameState extends Resource
# loads scene automatically when this GameState is loaded
@export var scene: PackedScene
Question
Is there a way to have a property reference a Resource file (GameState or scene) such that:
Recursion errors are not thrown when Resources store references to each other
Scenes are not automatically loaded when the Resource containing the property is loaded
The reference updates properly when the Resource file is renamed or moved
Workaround
One workaround I can think of is creating an enum for each GameState/Scene resource, having the resources store references to other resources using their enums, and creating a dictionary of enum → GameState/Scene. This works, but is not as convenient as directly referencing Resources.
WTF. I literally made this today, and had no problems with it:
@icon("res://assets/ui/icons/music-library.png")
extends Resource
class_name Song
@export var song: AudioStream
@export var title: String
@export var artist: String
@export var album: String
@export var album_link: String
AudioStream literally is a Resource.
I don’t know what your code looks like, but that’s literally my whole file. This is a shot in the dark, but try commenting out everything after your variable declarations and see if the error goes away?
Here’s a small example to reproduce the recursion error:
class_name ExampleResource extends Resource
@export var other_example_resource: ExampleResource
@export var other_resource: Resource
Create two ExampleResource files: example_resource1.tres and example_resource2.tres.
Set example_resource1.tres variables to point at example_resource2.tres:
Trying to set either of example_resource2.tres’ variables to point at example_resource1.tres will give the recursion error:
Oh that makes sense now. I think what you need is a helper object. Like the connection lines in the AnimationTree, or in the Visual Shader interface. All it does is keep a connection of where it’s going. An arrow pointing.
class_name ExampleConnection extends Resource
@export var example_resource_link: ExampleResource
class_name ExampleResource extends Resource
@export var connection_to: ExampleConnection
@export var other_resource: Resource
func get_connection_to() -> ExampleResource:
return connection.example_resource_link
You’re constructing a linked list. If you want a doubly-linked list so you know where you came from, you can add a second variable: @export var connection_from: ExampleConnection
