alternative.elm

type Action
  = Updated Response
  | APIError Error

update : Action -> Model -> ( Model, Effects Action )
update action model =
  case action of
    Updated response ->  -- do things
    APIError error ->
      let
        _ =
          case error of
            Http.Timeout ->
              Debug.log "API timeout" error

            Http.NetworkError ->
              Debug.log "Network error contacting API" error

            Http.UnexpectedPayload payload ->
              Debug.log ("Unexpected payload from API: " ++ payload) error

            Http.BadResponse status payload ->
              Debug.log ("Unexpected status/payload from API: " ++ (toString status) ++ "/" ++ payload) error
      in
        ( model, Effects.none )

requestUpdate : Effects Action
requestUpdate =
  Http.get decoder url
    |> Task.map Updated
    |> (flip Task.onError) (Task.succeed << APIError)
    |> Effects.task