MFlow Create and maintain dynamic Web applications as easy and fast as console applications
Quick start: basics for understanding and using MFlow Tutorial that show how to add dynamic effects to a web application using applicative and monadic combinators how Web applications are a particular case of what I call "the integration problem" that is caused by an inversion of control, common also in EAI, BPM, Workflows and Web Service Orchestration and IntegrationThis example shows a reverse counter
To avoid unnecessary load, the push process will be killed when reaching 0
The last push message will be an script that will redirect to the menu"
{-# OPTIONS -XQuasiQuotes -XCPP #-}
module PushDecrease ( pushDecrease) where
import Control.Concurrent.STM
import Text.Hamlet
import Control.Concurrent
-- #define ALONE -- to execute it alone, uncomment this
#ifdef ALONE
import MFlow.Wai.Blaze.Html.All
main= runNavigation "" $ transientNav pushDecrease
#else
import MFlow.Wai.Blaze.Html.All hiding(page)
import Menu
#endif
atomic= liftIO . atomically
pushDecrease= do
tv <- liftIO $ newTVarIO 10
page $
[shamlet|
<div>
<h2> Maxwell Smart push counter
<p> This example shows a reverse counter
<p> To avoid unnecessary load, the push process will be killed when reaching 0
<p> The last push message will be an script that will redirect to the menu"
<h3> This message will be autodestroyed within ...
|] ++> counter tv <++ b << "seconds"
where
counter tv = pageFlow "push" . push Html 0 $ do
setTimeouts 2 0 -- kill the thread after 2 s of incactivity, when count finish
n <- atomic $ readTVar tv
if (n== -1)
then do
script << "window.location='/'" ++> noWidget
else do
atomic $ writeTVar tv $ n - 1
liftIO $ threadDelay 1000000
h1 << (show n) ++> noWidget