Main.elm

Main.elm

import Html        exposing (..)
import Html.App    exposing (beginnerProgram, program)
import Html.Events exposing (onClick)
import Task
import Debug


type alias Model = Int

type Msg
  = Hello
  | Bye
  | Fail
  | NotFail

init : Int -> (Model, Cmd Msg)
init value =
  (value, Cmd.none)

view : Model -> Html Msg
view model =
  div []
    [ text <| toString model
    , button [ onClick Hello ] [ text "Hello" ]
    ]

update : Msg -> Model -> (Model, Cmd Msg)
update message model =
  case message of
    Hello -> (model, Task.perform Fail Bye)
    Fail  -> (model, Cmd.none)
    NotFail    -> (model, Cmd.none)
    Bye  -> (model, Cmd.none)
    
main =
  program
  { init  = init 2
  , update = update
  , view   = view
  , subscriptions = \_ -> Sub.none
  }