Small example if clearing input value in elm

ClearingInput.elm

import Html exposing (div, button, text, input, p)
import Html.App exposing (beginnerProgram)
import Html.Events exposing (onClick, onInput)
import Html.Attributes exposing (placeholder, value)


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


model =
  { personName = ""
  , inputPersonName = ""
  }


type Msg = Greet | InputPersonName String


view model =
  div []
    [ input [ placeholder "person name", onInput InputPersonName, value model.inputPersonName ] []
    , button [ onClick Greet ] [ text "Greet" ]
    , p [] [ text model.personName ]  
    ]


update msg model =
  case msg of
    Greet ->
    let 
      personName = model.inputPersonName
    in
      { model | personName = personName, inputPersonName = "" }

    InputPersonName name ->
      { model | inputPersonName = name }