coounter-delayed.elm

module Counter where

import Html exposing (..)
import Html.Attributes exposing (style)
import Html.Events exposing (onClick)
import Effects
import Task



-- MODEL
type alias Model = Int
initModel : Model
initModel = 0




-- Update
type Action = Increment | Decrement | Change Int


effectDelayedChange : Int -> Effects.Effects Action
effectDelayedChange delta =
    Effects.task <| Task.sleep 1000 `Task.andThen` \_ -> Task.succeed <| Change <| delta * 2



update : Action -> Model -> (Model, Effects.Effects Action)
update action model =
    case action of
        Increment -> (model, effectDelayedChange (0+1))
        Decrement -> (model, effectDelayedChange (0-1))
        Change delta -> (model + delta, Effects.none)


-- VIEW
view : Signal.Address Action -> Model -> Html
view address model =
    div [] [
        button [ onClick address Decrement ] [ text "-" ],
        div [ countStyle ] [ text (toString model)],
        button [ onClick address Increment ] [ text "+" ]
    ]


countStyle : Attribute
countStyle =
  style
    [ ("font-size", "20px")
    , ("font-family", "monospace")
    , ("display", "inline-block")
    , ("width", "50px")
    , ("text-align", "center")
    ]