Client-side file download in elm

ClientFileDownload.elm

module Main exposing (..)

import Html exposing (Html, Attribute, text, div, textarea, a, button)
import Html.App exposing (beginnerProgram)
import Html.Attributes exposing (..)
import Html.Events exposing (onInput)
import Http exposing (uriEncode)


main =
    beginnerProgram { model = "", view = view, update = update }


type Msg
    = NewContent String


update (NewContent content) oldContent =
    content


view content =
    div []
        [ textarea
            [ placeholder "Text to download ...."
            , onInput NewContent
            , rows 10
            , cols 30
            ]
            []
        , div []
            [ a
                [ type' "button"
                , href <| "data:text/plain;charset=utf-8," ++ uriEncode content
                , downloadAs "demo.txt"
                ]
                [ button [] [ text "Download" ] ]
            ]
        ]