CounterList.elm

module CounterList where

import Counter
import Html exposing (..)
import Html.Attributes exposing (..)
import Html.Events exposing (..)


-- MODEL
type alias Model =
  { counters : List (ID, Counter.Model )
  , nextID: ID

  }

init =
  { counters = []
  ,  nextID = 0
  }

type alias ID = Int

-- UPDATE

type Action
  = Insert
  | Remove ID
  | Modify ID Counter.Action

update action model =
  case action of
    Insert ->
      let newCounter = (model.nextID, Counter.init 0)
          newCounters = [newCounter] ++ model.counters
      in
        { model |
            counters <- newCounters,
            nextID <- model.nextID + 1
        }
    Remove id ->
      let removeFilter (counterID, counter) = not (counterID == id)
      in
        { model | counters <- List.filter removeFilter model.counters }

    Modify id counterAction ->
      let updateCounter ( counterID, counterModel) =
            if counterID == id
              then (counterID, Counter.update counterAction counterModel)
              else (counterID, counterModel)
      in
        { model | counters <- List.map updateCounter model.counters }

-- VIEW

view address model =
  let counters = List.map (viewCounter address) model.counters
      insert = button [ onClick address Insert ] [ text "Add"]
  in
    div [] ([insert] ++ counters)

viewCounter address (id, model) =
  div []
    [ Counter.view (Signal.forwardTo address (Modify id)) model
    , button [ onClick address (Remove id) ] [ text "Remove" ]
    ]