Do you retain a reference to your … | Apple Developer Forums

Do you retain a reference to your content events in RealityView?

Do you retain a reference to your content (RealityViewContent) events? For example, the Manipulation Events docs from Apple use _ to discard the result. In theory the event should keep working while the content is alive.

_ = content.subscribe(to: ManipulationEvents.WillBegin.self) { event in
event.entity.components[ModelComponent.self]?.materials[0] = SimpleMaterial(color: .blue, isMetallic: false)
}
_ = content.subscribe(to: ManipulationEvents.WillEnd.self)  { event in
    event.entity.components[ModelComponent.self]?.materials[0] = SimpleMaterial(color: .red, isMetallic: false)
}

We could store these events in state. I've seen this in a few samples and apps.

@State var beginSubscription: EventSubscription?

...

beginSubscription = content.subscribe(to: ManipulationEvents.WillBegin.self) { event in
    event.entity.components[ModelComponent.self]?.materials[0] = SimpleMaterial(color: .blue, isMetallic: false)
}

The main advantage I see is that we can be more explicit about when we remove the event. Are there other reasons to keep a reference to these events?