Http.getString at startup

HttpAction.elm

import StartApp
import Http
import Markdown
import Html exposing (Html, div, button, text)
import Html.Events exposing (onClick)
import Task exposing (Task)
import Effects exposing (Effects)

-- the URL of the README.md that we desire
readmeUrl : String
readmeUrl =
  "https://raw.githubusercontent.com/elm-lang/core/master/README.md"

initialModel = div [] []

type Action = FetchReadme String
            | ReceiveReadme String
            | FetchError Http.Error

fetchTask model urlString =
  let
      request = Task.map
        (\resp -> ReceiveReadme resp)
        (Http.getString urlString)

      neverFailingRequest = Task.onError
        request
        (\err -> Task.succeed (FetchError err))
  in
  ( model, Effects.task neverFailingRequest )

update action model =
  case action of
    FetchReadme urlString ->
      fetchTask model urlString
    ReceiveReadme str ->
        ( Markdown.toHtml str, Effects.none )
    FetchError err ->
        ( (div [] [text (toString err)]), Effects.none )

view actionDispatcher model =
  div []
  [  button [onClick actionDispatcher (FetchReadme readmeUrl)] [text "Fetch Readme"]
  ,  button [onClick actionDispatcher (FetchReadme "readmeUrl")] [text "Fetch Error"]
  ,  model
  ]

app =
    StartApp.start
        { init = fetchTask initialModel readmeUrl
        , update = update
        , view = view
        , inputs = []
        }


main =
    app.html


port tasks : Signal (Task Effects.Never ())
port tasks =
    app.tasks