Chaplin.Router → Source

This module is responsible for observing URL changes and matching them against a list of declared routes. If a declared route matches the current URL, a router:match event is triggered.

Chaplin.Router is a replacement for Backbone.Router and does not inherit from it. It is a stand-alone implementation with several advantages over Backbone’s default. Why change the router implementation completely?

In Backbone there are no controllers. Instead, Backbone’s Router maps routes to its own methods, serving two purposes and being more than just a router. Chaplin on the other hand delegates the handling of actions related to a specific route to controllers. Consequently, the router is really just a router. While the router has been rewritten for this purpose, Chaplin is using Backbone.History in the background. That is, Chaplin relies upon Backbone for handling hash URLs and interacting with the HTML5 History API (pushState).

Declaring routes in the routes file

By convention, all application routes should be declared in a separate file, the routes module. This is a simple module in which a list of match statements serve to declare corresponding routes. For example:

match '', 'home#index'
match 'likes/:id', controller: 'controllers/likes', action: 'show'
match('', 'home#index');
match('likes/:id', {controller: 'controllers/likes', action: 'show'});

Ruby on Rails developers may find match intuitively familiar. For more information on its usage, see below. Internally, route objects representing each entry are created. If a route matches, a router:match event is published, passing the route object and a params hash which contains name-value pairs for named placeholder parts of the path description (like id in the example above), as well as additional GET parameters.



Creates the Backbone.History instance.


Starts Backbone.History instance. This method should be called only after all routes have been registered.


Stops the Backbone.History instance from observing URL changes.

match([pattern], [target], [options={}])

Connects a path with a controller action.

  • pattern (String): A pattern to match against the current path.
  • target (String): Specifies the controller action which is called if this route matches. Optionally, replaced by an equivalent description through the options hash.
  • options (Object): optional

The pattern argument may contain named placeholders starting with a colon (:) followed by an identifier. For example, 'products/:product_id/ratings/:id' will match the paths /products/vacuum-cleaner/ratings/jane-doe as well as /products/8426/ratings/72. The controller action will be passed the parameter hash {product_id: "vacuum-cleaner", id: "jane-doe"} or {product_id: "8426", id: "72"}, respectively.

The target argument is a string with the controller name and the action name separated by the # character. For example, 'likes#show' denotes the show action of the LikesController.

You can also equivalently specify the target via the action and controller properties of the options hash.

The following properties of the options hash are recognized:

  • params (Object): Constant parameters that will be added to the params passed to the action and overwrite any values coming from a named placeholder

    match 'likes/:id', 'likes#show', params: {foo: 'bar'}
    match('likes/:id', 'likes#show', {params: {foo: 'bar'}});

    In this example, the LikesController will receive a params hash which has a foo property.

  • constraints (Object): For each placeholder you would like to put constraints on, pass a regular expression of the same name:

    match 'likes/:id', 'likes#show', constraints: {id: /^\d+$/}
    match('likes/:id', 'likes#show', {constraints: {id: /^\d+$/}});

    The id regular expression enforces the corresponding part of the path to be numeric. This route will match the path /likes/5636, but not /likes/5636-icecream.

    For every constraint in the constraints object, there must be a corresponding named placeholder, and it must satisfy the constraint in order for the route to match. For example, if you have a constraints object with three constraints: x, y, and z, then the route will match if and only if it has named parameters :x, :y, and :z and they all satisfy their respective regex.

  • name (String): Named routes can be used when reverse-generating paths using Chaplin.utils.reverse helper:

    match 'likes/:id', 'likes#show', name: 'like'
    Chaplin.utils.reverse 'like', id: 581  # => likes/581
    match('likes/:id', 'likes#show', {name: 'like'});
    Chaplin.utils.reverse('like', {id: 581});  // => likes/581

    If no name is provided, the entry will automatically be named by the scheme controller#action, e.g. likes#show.


Route a given path manually. Returns a boolean after it has been matched against the registered routes, corresponding to whether or not a match occurred. Updates the URL in the browser.

  • path can be an object describing a route by
    • controller: name of the controller,
    • action: name of the action,
    • name: name of a named route, can replace controller and action,
    • params: params hash.

For routing from other modules, Chaplin.utils.redirectTo can be used. All of the following would be valid use cases.

Chaplin.utils.redirectTo 'messages#show', id: 80
Chaplin.utils.redirectTo controller: 'messages', action: 'show', params: {id: 80}
Chaplin.utils.redirectTo url: '/messages/80'
Chaplin.utils.redirectTo('messages#show', {id: 80});
Chaplin.utils.redirectTo({controller: 'messages', action: 'show', params: {id: 80}});
Chaplin.utils.redirectTo({url: '/messages/80'});


Changes the current URL and adds a history entry without triggering any route actions.

Handler for the globalized router:changeURL request-response handler.

  • url: string that is going to be pushed as the page’s URL


Stops the Backbone.history instance and removes it from the router object. Also unsubscribes any events attached to the Router. On compliant runtimes, the router object is frozen, see Object.freeze.

Request-response handlers of Chaplin.Router

Chaplin.Router sets these global request-response:

  • router:route path[, options]
  • router:reverse name, params[, options], callback
  • router:changeURL url[, options]


Chaplin.Router is a dependency of Chaplin.Application which should be extended by your main application class. Within your application class you should initialize the Router by calling initRouter (passing your routes module as an argument) followed by start.

define [
], (Chaplin, routes) ->
  'use strict'

  class MyApplication extends Chaplin.Application
    title: 'The title for your application'

    initialize: ->
      @initRouter routes
], function(Chaplin, routes) {
  'use strict';

  var MyApplication = Chaplin.Application.extend({
    title: 'The title for your application',

    initialize: function() {
      Chaplin.Application.prototype.initialize.apply(this, arguments);

  return MyApplication;