Work with elm and select

Question

I try to understand how elm works with a custom example.

durationOption duration =
  option [value (toString duration) ] [ text (toString duration)]

view : Mode         


        

Answer 1

An example with onInput handler (you can also check the Ellie):

module Main exposing (main)

import Browser import Html exposing (Html, button, div, text, select, option) import Html.Attributes exposing (value, selected) import Html.Events exposing (onInput) import Dict exposing (Dict)

type alias Model =
    { options : Dict Int (String, Bool)
    }


initialModel : Model initialModel =
    { options = Dict.fromList [(0, ("All time", False)), (1, ("One week", True)), (2, ("24h", False))] 
    }


type Msg
    = Select String


update : Msg -> Model -> Model update msg model =
    case msg of
        Select value ->
            case String.toInt value of
                Just selectedID ->
                    let
                        changeSelection id (label, _) =
                            if id == selectedID then
                                (label, True)
                            else
                                (label, False)
                    in
                    {model | options = Dict.map changeSelection model.options}

                Nothing ->
                    model



view : Model -> Html Msg view model =
    let
        toOption (id, (label, isSelected)) =
            option [value (String.fromInt id), selected isSelected] [text label]
    in
    div []
        [ select [onInput Select] (List.map toOption <| Dict.toList model.options)
        , div [] [text "DEBUG"]
        , div [] [text <| Debug.toString model.options]
        ]


main : Program () Model Msg main =
    Browser.sandbox
        { init = initialModel
        , view = view
        , update = update
        }