middleware example

gistfile1.js

var o2x = require('object-to-xml');
var j2c = require('json-2-csv');

function(req, res, next) {
  
  if(req.accepts('application/json')) {
    return res.json(req.payload);
  }

  if(req.accepts('text/xml')) {
    res.set('content-type', 'text/xml');
    return res.send(o2x(req.payload));
  }

  if(req.accepts('text/csv')) {
    req.set('content-type', 'text/csv');
    return res.send(j2c(req.payload));
  }

  return res
    .status(406)
    .send('Not Acceptable');
}