Chainable Async Router

router.js

var ChainableRouter = BaseRouter.extend({

  constructor: function(options) {
    BaseRouter.apply(this, arguments);

    this.options = options || {};

    this._initRoutes();
  },

  _initRoutes: function() {
    var routes = this.getOption('appRoutes'),
      controller = this.getOption('controller');

    if (!routes) { return; }

    // Backbone requires reversed order of routes
    _.chain(routes).keys().reverse().each(function(key) {
      this.addRoute(key, routes[key], controller);
    }, this);
  },

  addRoute: function(route, handlers, controller) {
    this.route(route, _.map(_.isArray(handlers) ? handlers : [handlers], function(handler) {
      var method;

      if (_.isFunction(handler)) { return handler; }

      if (!controller) {
        throw new Error('A controller must be specified for route "' + route + '"');
      }

      method = controller[handler];

      if (!method) {
        throw new Error('Method "' + handler + '" was not found on the controller');
      }

      return _.bind(method, controller);
    }));
  },

  onNavigate: function(routeData) {
    var index = 0,
      that = this;

    this._currentRoute = routeData;

    function next(resp) {
      var handler = routeData.linked[index];

      index += 1;

      if (handler && that._currentRoute === routeData) {
        handler(resp || routeData, next);
      }
    }

    next();
  },

  // Proxy `getOption` to enable getting options from this or this.options by name.
  getOption: Marionette.proxyGetOption
});