broadway

Lightweight App extensibility and hookable middleware customization.

Usage

broadway is designed to be the littlest possible extensibility for server applications. It is does not take any other external dependencies besides those to expose basic "start middleware".

Additional functionality may be added through .mixin(base, redefine):

var express = require('express'),
    App = require('broadway');

//
// Create a new base App.
//
var app = new App({ http: 8080 });

//
// Then mixin `express` functionality later on. This
// can be called multiple times. By default: it will
// only define a single property on your app once.
//
app.mixin(express());

//
// Do anything you want asynchronously before
// the application starts.
//
app.preboot(function (app, options, next) {
  console.log('Starting up...');
  next();
});

//
// Start listening on HTTP port passed in to
// App when it was created above.
//
app.start(function (err) {
  if (err) {
    console.error('Error on startup: %s', err.message);
    return process.exit(1);
  }

  console.log('Listening over HTTP on port %s', this.given.http);
});

"Hookable" middleware

Because broadway exposes a generic hook mechanism from understudy it is possible to write hooks into your middleware easily. Consider the following example that defines hookable "auth" handlers into its existing authorization middleware:

var express = require('express'),
    basicAuth = require('basic-auth'),
    App = require('broadway');

//
// Create an app with default http options,
// mixin all express functions
//
var app = new App({ http: 8080 }, express());

//
// Define a simple "auth" middleware that only
// performs Basic Auth.
//
app.use(function auth(req, res, next) {
  //
  // Before checking and/or parsing the Basic Auth
  // header allow others to attempt their auth methods.
  //
  app.perform('auth', req, res, function (done) {
    var creds = basicAuth(req);

    if (req.authed) {
      return done();
    }
    else if (!creds || creds.name !== 'bob' || creds.pass !== 'secret') {
      res.writeHead(401, { 'WWW-Authenticate': 'Basic realm="example"' });
      res.end('Unauthorized\n');
      return;
    }

    done();
  }, next);
});

//
// Hook into the new "auth middleware" defined above
// to add support for the `X-AUTH-TOKEN` header.
//
app.before('auth', function (req, res, next) {
  var bearerToken = req.headers['x-auth-token'];

  if (bearerToken === 'golden-ticket') {
    req.authed = true;
  }

  next();
});

// ... continue starting the app as usual.

Tests

All tests are written with mocha and should be run with npm:

  $ npm test

Charlie Robbins

License: MIT