An Epress middleware example

app.js

var express = require('express');
var bodyParser = require('body-parser');
var app = express();

app.use(bodyParser.json())
  .use(function(req, res, next) {
    // Add the username to the parsed body
    // set by bodyParser middleware
    req.body.username = 'David';
    next();
  })
  .use(function(req, res) {
    res.json(req.body || { message: 'No content' });
  });

app.listen(3000);