reactive.scala

class reactiveweb extends Logger{

  val statesSelect= Select(Val(CitiesAndStates3.states))
  statesSelect.selectedIndex.value ()= Some(0)

  val validCitiesSignal= statesSelect.selectedItem map {
    case None =>  Nil
    case Some(state) => CitiesAndStates3.citiesFor(state)
  }

  
  val citiesSelect = Select(validCitiesSignal)
  citiesSelect.selectedIndex.value ()= Some(0)

  val validIdsSignal = citiesSelect.selectedItem.map(_.toList flatMap CitiesAndStates3.idsFor)
  val idsSelect = Select(validIdsSignal)

  def render ={
    "#states" #> statesSelect &
    "#cities" #> citiesSelect &
    "#ids"    #> idsSelect
  }