DeviceTracking

SketchSystems.spec

DeviceTracking
  NotOnItinerary*
    setItinerary -> OnItinerary
    updateLocation -> NotOnItinerary
  OnItinerary
    clearItinerary -> NotOnItinerary
    setItinerary -> OnItinerary
    OnTime*
      arrived at final destination -> NotOnItinerary
      irrecoverably late -> FailedItinerary    
      Start?*
        at next station -> Waiting
        walk to next station -> Walking
      Alighting?
        at next station -> Waiting
        walk to next station -> Walking
      Walking
        arrived at station -> Waiting
      InTransit      
        OnRoute*
          arrived at station -> Alighting?
          caught wrong bus -> OffRoute
        OffRoute
          reroute -> OnItinerary
          was just detour -> OnRoute
      Waiting
        board -> InTransit
        catch next trip -> Waiting
    FailedItinerary
      reroute -> OnItinerary

SketchSystems_prototype.js

function render(model){
  let current_state_name = model.active_states[0].name;
  return $("h1",
           {style: {color: "darkBlue"}},
           `The current state is: ${current_state_name}`);
}