Scoped routers.

example.js

function wrapRouter(addRoute, basicFunctionality) {
  	return {
		register: function (rule, handler) {
			require("util").inherits(handler, basicFunctionality);
			var factory = function (req, res) {
				this.request = req;
				this.response = res;
			};
			factory.prototype = handler;
			addRoute(rule, function (req, res) {
				new factory(req, res).run();
			});
		}
	}
}

var router = wrapRouter(some3rdPartyRouter.addRoute, {
	error: someTemplateEngine.compile("error.tpl"),
	withErrorHandler: function (successHandler) {
		var self = this;
		return function (err, data) {
			if (err == null) successHandler.call(self, data);
			else self.error.render(self.response, err);
		}
	},
	makeQuery: someFancyParser.urlToMongoDbSelector,
});

router.register(someRule, {
	init: function () {
		this.getData(this.request.url, this.withErrorHandler(this.handleData));
	},
	template: someTemplateEngine.compile("showdata.tpl"),
	getData: function (query, callback) {
		myDb.findAll(makeQuery.process(query), callback)
	},
	handleData: function (data) {
		this.template.render(this.response, data);
	}
});