EFP #1 in Elm

01_hello.elm

-- Exercises For Programmers #1

import Html exposing (Html, text, div, p, input, label)
import Html.Attributes exposing (id, value, for)
import Html.Events exposing(on, targetValue)
import StartApp.Simple as StartApp
import Signal exposing (Address)


type Action
  = NoOp 
  | UpdateModel String

model : String
model = 
  ""
 
view : Address Action -> String -> Html
view address model =
  div [] [
    label [for "name"] [text "Enter your name"],
    input [
      id "name", 
      on "input" targetValue (\value -> Signal.message address (UpdateModel value)), 
      value model ] [],
    p [] [ text (output model)]
  ]
  
output string =
  if string == "" then "Enter your name in the box." else "Hello, " ++ string
  
update action model =
  case action of  
    NoOp ->
      model
    UpdateModel name ->
      name
      
      
main =
  StartApp.start { model = "", view = view, update = update }