location.elm

module Location

type Location
  = None
  | SelectCountry (List Country)
  | CountrySelected Country
  | SelectRegion Country (List Region)
  | RegionSelected Country Region
  | SelectCity Country Region (List City)
  | Complete Country Region City
  
type Msg
  = CountriesLoaded (List Country)
  | CountrySelected Country
  | RegionsLoaded Country (List Region)
  | RegionSelected Country Region
  | CitiesLoaded Country Region (List City)
  | CitySelected Country Region City
    
init : (None, getCountries)

forward : Msg -> Location -> (Location, Cmd Msg)
forward msg location =
  case msg of
    CountriesLoaded cs -> (SelectCountry cs, Cmd.none)
    CountrySelected c -> (CountrySelected c, getRegions c)
    RegionsLoaded c rs -> (SelectRegion c rs, Cmd.none)
    RegionSelected c r -> (RegionSelected c r, getCities c r)
    CitiesLoaded c r cs -> (SelectCity c r cs, Cmd.none)
    CitySelected co r ci -> (Complete co r ci)
    
getCountries : Cmd (CountriesLoaded (List Country))

getRegions : Country -> Cmd (RegionsLoaded Country (List Region))

getCities : Country -> Region -> Cmd (CitiesLoaded Country Region (List City))