Observable state is the observer pattern applied to state. It means that listeners can subscribe to state, receiving the new state whenever state changes.
It’s easy to imagine how observable state might be useful in a State-View framework such as React — the view can subscribe to state and update whenever it receives a new state.
What may not be so obvious is how observable state enables reactive and composable state, and just how powerful reactive and composable state are.
When all entities in the system support the same observable state mechanism, the entities can be connected to each other…