A strategy to decouple the requests from the rest o the app in order to facilitate mock results.

MockRequests.elm

import Html exposing (..)
import Html.Attributes exposing (style, id, type', src)
import Html.Events exposing (onClick)
import Task exposing (Task, succeed) 
import StartApp 
import Effects exposing (Never) 
import Json.Decode exposing ( (:=), string ) 
import Http exposing (send, Request, empty, defaultSettings, fromJson ) 
import Task exposing (andThen)

debug = False


corsGet : Request
corsGet =
    { verb = "GET"
    , headers =
        [ ("Origin", "http://elm-lang.org")
        , ("Access-Control-Request-Method", "GET")
        , ("X-Mashape-Key", "aZPQfgrZSAmshIcZ0vt29ougt630p1Lv5w9jsnvTUZ68uvSW90")
        , ("Access-Control-Request-Headers", "X-Custom-Header")
        ]
    , url = "https://andruxnet-random-famous-quotes.p.mashape.com/cat=movies"
    , body = empty
    }

dataService : String -> Task x () -- converts requests received in the query mailbox to messages to results mailbox
dataService req = 
  if req == "" 
  then 
    succeed () -- It prevents the execution of the default request in the querry signal
  else 
    if debug 
    then 
      Signal.send results.address (Ok "Do or not do, there is no try!")
    else 
      ( fromJson  ("quote" := string) (send defaultSettings corsGet)
      |> Task.mapError (\e -> toString e) 
      |> Task.toResult) `andThen` (Signal.send results.address)
    

query = Signal.mailbox ""

results = Signal.mailbox (Ok "")

port requests : Signal (Task x ())
port requests = Signal.map dataService query.signal
   
type alias Model = 
  { output : String
  , serviceAddress : Signal.Address String} 


init : (Model, Effects.Effects Action) 
init = ({ output = "start", serviceAddress = query.address}, Effects.none)


messageToServiceEffect : Signal.Address String -> String -> Effects.Effects Action
messageToServiceEffect address req=
  Signal.send address req
  |> Task.map NoOp 
  |> Effects.task
  
type Action = NewResult (Result String String) | RequestValue | NoOp ()  
  
  
update : Action -> Model -> (Model, Effects.Effects Action) 
update action model =
  case action of
    NewResult result ->
      case result of
        Ok value -> ({ model | output <- "It worked! I received: \"" ++ value++"\""}, Effects.none)
        Err error -> ({ model | output <- "Error: " ++ error}, Effects.none)
        
    RequestValue -> (model, messageToServiceEffect model.serviceAddress "Get Shorty!")  
    
    NoOp () -> (model, Effects.none) 
    

view address model =
  div []
  [ button [onClick address RequestValue ] [text "Get Quote"]
  , p [] [text model.output]
  ]
    
app =
  StartApp.start
    { init = init
    , update = update
    , view = view
    , inputs = [Signal.map NewResult results.signal]
    }



main =  app.html

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