simple flash scope using expressjs

app.js

// poor mans flash scope
// message appears once, but reloading in the browser makes it vanish
app.use(function(req, res, next){
  if (req.session.message !== null) {
    res.locals.message = req.session.message
    req.session.message = null
  }
  next();
});

// works for rendering
app.get('/', function(req, res) {
  req.session.message = "foo bar baz";
  res.render('index', { title: 'Express' });
})

// works even for redirects
app.get('/', function(req, res) {
  req.session.message = "foo bar baz";
  res.redirect('/');
})

/* in jade template
if message
  div.ui.blue.message= message
*/