express-defaultlocals

npm install express-defaultlocals --save

Similar to dynamicHelpers of express 2.0, but as a middleware for express 4.0.

Because it's done as a middleware, you can use it on a router rather than on app, e.g.:

var router = require('express').Router()

router.use(require('express-defaultlocals')(function(req) {
  return {
    user: req.user
  }
}))

router.get('/', function() {
  res.render('homepage' /* it's as though ", { user: req.user }" is here automatically */);
})