switched

Route your data through a series of middleware functions.

$ npm install switched

var router = require('switched');
router.on(/[\w\s]+/, function (arg, next, end) {
  arg.count = 0;
  next();
});
router.on(function (arg, next, end) {
  arg.count++;
  next();
});
router.on(function (err, arg, next, end) {
  console.error(err);
  arg.count++;
  next();
});
router.on('some event', function (arg, next, end) {
  arg.count++;
  console.log('count %s', arg.count);
});
router('some event', {some:'argument'});

Features

• Express-like routing capabilties for data.
• Gives you more control over how data is handled.
• Attach Switched instances to other Switched instances.
• Support for "wildcard" (*) and Regular Expression matching.

API

Router

Get the Router class.

var Router = require('switched');

The use and on methods are equivalent. They also can be chained.

var router = Router()
  .use(function (arg, next) { })
  .use(function (arg, next) { })
  .use(function (arg, next) { });

Router#()

Make a Router instance

var router = Router();

Router#use(fn:Function, ...)

Attach a function to the router.

router.use(function (arg, next) {
  //do something!
  next();
});

You can pass in multiple functions.

var a = function (arg, next, end) { next() };
var b = function (arg, next, end) { next() };
var c = function (arg, next, end) { next() };
 
router.use(a,b,c); 

You can pass in a function that accepts an Error object.

router.use(function (err, arg, next, end) {
  console.error(err);
  
  //calling next(err) will invoke the next error handler.
  //to resume operation just call next()
  next(err);
});

Router#use(event:String, fn:Function, ...)

Bind the function to the event.

router.use('some event', function (arg, next) {
  next();
});

You can also pass in multiple functions for handling the event.

var chop = function (arg, next, end) { next() };
var clean = function (arg, next, end) { next() };
var pretty = function (arg, next, end) { next() };
 
router.use('some event', chop, clean, pretty);

Router#use(event:RegExp, fn:Function, ...)

Bind the function using a RegExp pattern to match the event.

router.use(/\w+/, function (arg, next, end) {
  next();
});

You can also pass in multiple functions for handling the event.

var chop = function (arg, next, end) { next() };
var clean = function (arg, next, end) { next() };
var pretty = function (arg, next, end) { next() };
 
router.use(/\w+/, chop, clean, pretty);

Router#use(router:Router, ...)

You can attach another Router instance to your Router instance.

var another = Router();
another.use(function (arg, next, end) { next(); });
 
router.use(another);

Attach multiple routers in a single call.

var foo = Router();
foo.use(function (arg, next, end) { next(); });
 
var bar = Router();
bar.use(function (arg, next, end) { next(); });
 
var baz = Router();
baz.use(function (arg, next, end) { next(); });
 
router.use(foo, bar, baz);

Router#use(name:String, router:Router, ...)

Just like attaching a function to the router given the event. You can attach Router instance as well to the event.

var foo = Router();
foo.use(function (arg, next, end) { next(); });
 
router.use('some event', foo);

Attach multiple routers in a single call to the event too.

var foo = Router();
foo.use(function (arg, next, end) { next(); });
 
var bar = Router();
bar.use(function (arg, next, end) { next(); });
 
var baz = Router();
baz.use(function (arg, next, end) { next(); });
 
router.use('some event', foo, bar, baz);

Router#use(fns:Array, ...)

Attach an Array of Fuction's or Router instances, or an Array or Arrays .

var middleware = [
  function (arg, next, end) { next(); },
  [
    function (arg, next, end) { next(); },
    Router().use(function (arg, next, end) { next(); }),
    function (arg, next, end) { next(); },
  ],
  Router().use(function (arg, next, end) { next(); })
];
 
var errHandler = function (err, arg, next, end) { next(err); } 
 
router.use(middleware, errHandler);

Router#use(name:String, fns:Array, ...)

Attach everything to an event.

var middleware = [
  function (arg, next, end) { next(); },
  [
    function (arg, next, end) { next(); },
    Router().use(function (arg, next, end) { next(); }),
    function (arg, next, end) { next(); },
  ],
  Router().use(function (arg, next, end) { next(); })
];
 
var errHandler = function (err, arg, next, end) { next(err); } 
 
router.use('only this event', middleware, errHandler);

Router#on(...)

This is an alias to to the use method. It does the same thing.

router.on(function (arg, next, end) { next() });

Installation and Environment Setup

Install node.js (See download and install instructions here: http://nodejs.org/).

Clone this repository

> git clone [e-mail]:turbonetix/switched.git

cd into the directory and install the dependencies

> cd switched
> npm install && npm shrinkwrap --dev

Running Tests

Install coffee-script

> npm install coffee-script -g

Tests are run using grunt. You must first globally install the grunt-cli with npm.

> sudo npm install -g grunt-cli

Unit Tests

To run the tests, just run grunt

> grunt spec