Http can only get httpbin.org - http

Question

When running the following program in elm-reactor (or using elm-make for that matter), the only webpage I have found that it actually GETs is httpbin. Otherwise, I see a Http.NetworkError, even on reliable sites such as "http://google.com" or "http://stackoverflow.com". I am utterly befuddled as to why this might be, can anyone point out my error?
module Main (..) where
import Http
import Html exposing (..)
import Effects
import Html.Events as Events
import StartApp
import Task
-- MODEL
type alias Model =
{ output : String }
type Action
= Response String
| Request String
| HTTPError Http.Error
-- UPDATE
update : Action -> Model -> ( Model, Effects.Effects Action )
update act mod =
case act of
Response str ->
( { mod | output = str }, Effects.none )
Request srv ->
let
effects =
srv
|> Http.getString
|> Task.map Response
|> flip Task.onError (Task.succeed << HTTPError)
|> Effects.task
in
( { mod | output = "GET: " ++ srv }, effects )
HTTPError err ->
( { mod
| output =
"Error: "
++ case err of
Http.Timeout ->
"Timeout"
Http.UnexpectedPayload str ->
"Unexpected payload: " ++ str
Http.BadResponse code str ->
"Bad response: " ++ toString code ++ ": " ++ str
Http.NetworkError ->
"Network error"
}
, Effects.none
)
-- VIEW
view : Signal.Address Action -> Model -> Html.Html
view address mod =
div
[]
[ div
[]
[ input
[ Events.on "input" Events.targetValue (Request >> Signal.message address) ]
[]
]
, div [] [ text mod.output ]
]
-- MAIN
app : StartApp.App Model
app =
StartApp.start
{ init = ( { output = "No requests made" }, Effects.none )
, update = update
, view = view
, inputs = []
}
main =
app.html
port tasks : Signal (Task.Task Effects.Never ())
port tasks =
app.tasks

Answer 1

You are most likely running into cross-origin browser restrictions. Take a look at your browser javascript console as you make requests that fail. Chrome logs an error like this:
XMLHttpRequest cannot load https://www.stackoverflow.com/. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://elm-lang.org' is therefore not allowed access.
Your working httpbin example link includes the HTTP header Access-Control-Allow-Origin: *, which is the least restrictive setting.
You can read up more on these types of issues, and the way to get around them, by looking up information on CORS (which stands for Cross Origin Http Request).