"push" function doesn't show data the first data update

Description: push function requires clicking the submit button one additional time in browser before it receives the data. In other words, push requires two data updates before it shows in browser. Line: haskell <** push Append 0 (do Version:

GHC 7.10.2
MFlow-0.4.5.11

Note this code was found in the tutorial.

{-# LANGUAGE OverloadedStrings #-}

import MFlow.Wai.Blaze.Html.All
import System.IO.Unsafe
import Control.Concurrent.MVar

res = unsafePerformIO $ newEmptyMVar :: MVar Int  

main= runNavigation "" . step . page $ do
   "Hi, I' m not refreshed, unless you "
     ++>  wlink () "click here" 
     <++ " in which case, a navigation happens"

    <** (autoRefresh .  pageFlow "s" $ do
          n  <- "First  "  ++> getInt Nothing   <++ br
          n' <- "Second " ++> getInt (Just n)  <++ br
          liftIO $ putMVar res $ n + n' 
          noWidget 
         <** br ++> pageFlow "button" (submitButton "submit"))

    <** push Append 0  (do
            n <- liftIO  $ takeMVar res  
            b << (show n) ++> br ++> noWidget )

agocorona / MFlow

"push" function doesn't show data the first data update #65