gistfile1.hs

checkbox :: Bool -> IO (Elem, Signal Bool)
checkbox checked = do
  c <- newElem "input"
  (p,s) <- emptyPipe
  setProp c "type" "checkbox"
  sink (\isChecked -> do
    setProp c "checked" $ if isChecked then "true" else ""
    ) s 
  setCallback c OnChange (do 
    checked <- getProp c "checked"
    write p $ checked == "true"
    )   
  write p checked
  return (c,s)