Cat gif fetcher

Main.elm

module Main exposing (..)

import Html exposing (Html, button, div, h1, h2, img, text)
import Html.Attributes exposing (src)
import Html.Events exposing (onClick)
import Http exposing (Error, get)
import Json.Decode exposing (Decoder, at)


main : Program Never Model Msg
main =
    Html.program
        { init = init
        , view = view
        , update = update
        , subscriptions = \x -> Sub.none
        }



-- MODEL


type alias Model =
    { topic : String
    , gifUrl : String
    }


initialModel : Model
initialModel =
    Model "cats" "waiting.gif"


init : ( Model, Cmd Msg )
init =
    ( initialModel, foo )


foo : Cmd Msg
foo =
    let
        ( _, cmd ) =
            update MorePlease initialModel
    in
    cmd



-- UPDATE


type Msg
    = MorePlease
    | NewGif (Result Http.Error String)


update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    case msg of
        MorePlease ->
            ( model, getRandomGif model.topic )

        NewGif (Ok newUrl) ->
            ( { model | gifUrl = newUrl }, Cmd.none )

        NewGif (Err _) ->
            ( model, Cmd.none )


getRandomGif : String -> Cmd Msg
getRandomGif topic =
    let
        url =
            "https://api.giphy.com/v1/gifs/random?api_key=dc6zaTOxFJmzC&tag=" ++ topic

        request =
            Http.get url decodeGifUrl
    in
    Http.send NewGif request


decodeGifUrl : Json.Decode.Decoder String
decodeGifUrl =
    Json.Decode.at [ "data", "image_url" ] Json.Decode.string



-- VIEW


view : Model -> Html Msg
view model =
    div []
        [ h2 [] [ text model.topic ]
        , img [ src model.gifUrl ] []
        , button [ onClick MorePlease ] [ text "More Please!" ]
        ]

Wanting to fetch a gif when the program started, I had to create foo (line 37 and 40) to call update.
Is there a better way? Feels a bit hacky...