XHR with interruptible FFI

XhrB.hs

{-# LANGUAGE JavaScriptFFI #-}

module XhrB (xhr) where

import GHCJS.Types
import Control.Exception (onException)

data XHR_
type XHR = JSRef XHR_

foreign import javascript unsafe
  "new XMLHttpRequest()"
  js_createXHR :: IO XHR

foreign import javascript unsafe
  "$1.abort();"
  js_abortXHR :: IO ()

foreign import javascript interruptible
  "$2.open('GET', $1);\
  \$2.onload = function() { $c($2.responseText); };\
  \$2.send();"
  js_sendXHR :: JSString -> XHR -> IO JSString

xhr :: JSString -> IO JSString
xhr url = do
  x <- js_createXHR
  js_sendXHR url x `onException` js_abortXHR x