Learnt about the Event Bus pattern a.k.a global signals.
Instead of letting child nodes handle their own signals, we centralise them at the highest point in a Godot game state,[ an autoloaded singleton. This creates a singleton (class) available to all nodes at runtime. If we set up signals in this class, we can invoke this signal in any node simply by referring to it any other node e.g. GlobalSignal.hit.emit(). This also means that any other node can subscribe to the events of this Global signal like its broadcasting from the highest level. This pattern has been useful when constructing a HUD for a game. When my enemies die I need to emit how many points that were to show it on the UI, the HUD.
GLobalSignal
signal: points
/ \
/ HUD
/ - GlobalSignal.points.connect(update_score)
Enemy
- GLobalSignal.emit.points()