websocketecho.elm

import Html exposing (..)
import Html.App as Html
import Html.Events exposing (..)
import WebSocket exposing (..)

main : Program Never
main =
  Html.program
    { init = init
    , view = view
    , update = update
    , subscriptions = subscriptions
    }

-- MODEL

type alias Model =
  { msg : String
  , error : String}

init : (Model, Cmd Msg)
init =
  -- Subscriptions based Cmd's don't work here
  (Model "" "", WebSocket.send url "hello first time" )

-- UPDATE

type Msg
  = Send String
  | Receive String


update : Msg -> Model -> (Model, Cmd Msg)
update action model =
  case action of
    Send msg ->
      ( model, WebSocket.send url msg )
    Receive msg ->
      ( { model | msg = msg }, Cmd.none )


url : String
url = "ws://echo.websocket.org"

-- SUBSCRIPTIONS

subscriptions : Model -> Sub Msg
subscriptions model = listen url Receive

-- VIEW

view : Model -> Html Msg
view model =
  div []
    [ button [ onClick (Send "Hello again") ] [ text "Say Hello" ]
    , div [] [ text (model.msg) ]
    ]