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A node Express router middleware for Ajax RESTful API base on certain folder path.

Rainbow mapping all HTTP request route to controllers folder each as path to file as URL.


$ npm install rainbow


In your express application main file app.js:

var express = require('express');
var rainbow = require('rainbow');
var app = express();
// Here using Rainbow to initialize all routers 


All your controllers for catching HTTP request should be defined in each file in controllers/ folder (could be changed) as same path in URL.

This is the core design for Rainbow! And it makes routing much simpler only by files' paths!

Here writes a router something.js in your controllers/ folder like this:

exports.GET = function (req, res) {
    res.send(200, 'Simple getting.');

If you need some filters, just add a filters array property which contains your filters in filters/ folder to the handle function like this:

exports.GET = function (req, res) {
    res.send(200, 'Simple getting.');
// add filters 
exports.GET.filters = ['authorization'];

Also you could define other HTTP methods handlers, but make sure in one file each URL! Example in controllers/user.js:

exports.GET = function (req, res) {
    User.find({where:}).success(function (user) {
        res.send(200, user);
exports.PUT = function (req, res) {
    User.create(req.body).success(function (user) {
// You can also define `post` and `delete` handlers. 
// ... 

If you want all methods to be process in only one controller(something not RESTful), just make exports to be the handle function:

module.exports = function (req, res) {
    // all your process 

You can write controllers with coffeescript using .coffee in example controllers/

exports.GET = (req, res) ->
    .success (user) ->
        res.send 200user
exports.PUT = (req, res) ->
    .success (user) ->


Rainbow started to support param form URL from version 0.1.0. Now you can define your controllers URL with params resolved by native Express like this:

exports.GET = function (req, res) {
    var id =;
    // your business 
exports.GET.params = ':id?';

Or you can use regular expression also:

exports.GET = function (req, res) {
exports.GET.params = /(\d+)(?:\.\.(\d+))?/;

But make sure no regular expression ^ used as starter and $ as ender, or rainbow could not resolve the expression correctly.


Make sure the filters you need had been defined in filters/ folder (could be changed) as same module name, because them will be required when initilizing. Here authorization.js is a example for intecepting by non-authenticated user before GET http://yourapp:6060/something:

module.exports = function (req, res, next) {
    console.log('processing authorization...');
    var session = req.session;
    if (session.userId) {
        console.log('user(%d) in session', session.userId);
    } else {
        console.log('out of session');
        // Async filter is ok with express! 
        db.User.find().success(function (user) {
            if (!user) {

You could see filters is as same as a origin router in Express, just be put together in filters/ folder to be interceptors like in Java SSH.

Filters also support variable name of filter function in same file than string filter file name in filters directory (from v0.4):

// controller file test.js route to [GET]/test 
function myFilter (req, res, next) {
    // blablabla... 
exports.GET = function (req, res) {
    // blablabla... 
exports.GET.filters = [myFilter];

If you need some filters to be applied for all methods in an URL, you could use URL level filters definition:

// controller file test.js route to [GET|POST]/test 
exports.GET = function (req, res) {};
exports.POST = function (req, res) {};
exports.POST.filters = ['validation'];
exports.filters = ['session'];

When user GET:/test the filter session would run, and when POST:/test URL level filter session run first and then validation.

Change default path

Controllers and filters default path could be changed by passing a path config object to route function when initializing:

rainbow.route(app, {
    controllers: '/your/controllers/path',
    filters: '/your/filters/path'

These paths are all RELATIVE to your app path!


  1. Gmail me: mytharcher
  2. Write a issue
  3. Send your pull request to me.

MIT Licensed