IntReactable.gd

class_name IntReactable extends Reactable

@export var value: int:
	set(other_value):
		if value != other_value:
			value = other_value
			react()

Main.gd

extends Node

@export var valor: Other

func _ready() -> void:
	valor = Other.new()
	valor.value1 = IntReactable.new()
	valor.value2 = IntReactable.new()
	valor.reacted.connect(self.reage)
	valor.value1.value = 10
	valor.value2.value = 50

func reage(source: Other, cause: Reactable) -> void:
	print(source.value1.value)
	print(source.value2.value)
	print(cause == source.value1)
	print(cause == source.value2)

Other.gd

class_name Other extends Reactable

@export var value1: IntReactable:
	set(other_value):
		if value1 != other_value:
			depends_on(other_value)
			release(value1)
			value1 = other_value
			react()

@export var value2: IntReactable:
	set(other_value):
		if value2 != other_value:
			depends_on(other_value)
			release(value2)
			value2 = other_value
			react()

Reactable.gd

@abstract class_name Reactable extends Resource


signal reacted(source: Reactable, cause: Reactable)


@export var dependencies: Array[Reactable] = []


func _init() -> void: for dependency in dependencies: dependency.reacted.connect(self._propagate)


func depends_on(dependency: Reactable) -> void:
	dependencies.append(dependency)
	dependency.reacted.connect(self._propagate)


func release(dependency: Reactable) -> void:
	if dependency in dependencies:
		dependencies.erase(dependency)
		dependency.reacted.disconnect(self._propagate)


func react(cause: Reactable = null) -> void: reacted.emit(self, cause if cause != null else self)
func _propagate(_source: Reactable, cause: Reactable) -> void: react(cause)