Clientside router with fallbacks for browsers that don't support pushState. Mostly lifted from Backbone.js.

Ampersand-router also adds a redirectTo method which is handy for doing "internal" redirects without breaking backbutton functionality in the browser.

Part of the Ampersand.js toolkit for building clientside applications.

npm install ampersand-router

In this example the router is trigger a newPage event along with the instance of a page. It is up to your application to listen for this event on the router and then do something with the page instance.

This is helpful when paired with the ampersand-view-switcher#set method to ensure that the page instance is rendered into the correct container and it gets cleaned up properly via its remove method when a new page gets triggered by the router. Check out how the ampersand cli accomplishes this within its router and view-switcher.

var Router = require('ampersand-router');


module.exports = Router.extend({
    routes: {
        '': 'home',
        'users/:id': 'userDetail',
        'info': 'info'
    },

    // ------- ROUTE HANDLERS ---------
    home: function () {
        this.trigger('newPage', new HomePage());
    },

    // redirect example
    userDetail: function (id) {
        var user = app.users.get(id);
        if (user) {
            this.trigger('newPage', new HomePage());
        } else {
            this.redirectTo('users');
        }
    }

    ...
});

Get started by creating a custom router class. Define actions that are triggered when certain URL fragments are matched, and provide a routes hash that pairs routes to actions. Note that you'll want to avoid using a leading slash in your route definitions:

var AppRouter = AmpersandRouter.extend({

  routes: {
    "help":                 "help",    // #help
    "search/:query":        "search",  // #search/kiwis
    "search/:query/p:page": "search"   // #search/kiwis/p7
  },

  help: function() {
    //...
  },

  search: function(query, page) {
    //...
  }

});

The routes hash maps URLs with parameters to functions on your router (or just direct function definitions, if you prefer), similar to the View's events hash. Routes can contain parameter parts, :param, which match a single URL component between slashes; and splat parts *splat, which can match any number of URL components. Part of a route can be made optional by surrounding it in parentheses (/:optional).

For example, a route of "search/:query/p:page" will match a fragment of #search/obama/p2, passing "obama" and "2" to the action.

A route of "file/*path" will match #file/nested/folder/file.txt, passing "nested/folder/file.txt" to the action.

A route of "docs/:section(/:subsection)" will match #docs/faq and #docs/faq/installing, passing "faq" to the action in the first case, and passing "faq" and "installing" to the action in the second.

Trailing slashes are treated as part of the URL, and (correctly) treated as a unique route when accessed. docs and docs/ will fire different callbacks. If you can't avoid generating both types of URLs, you can define a "docs(/)" matcher to capture both cases.

When the visitor presses the back button, or enters a URL, and a particular route is matched, the name of the action will be fired as an event, so that other objects can listen to the router, and be notified. In the following example, visiting #help/uploading will fire a route:help event from the router.

routes: {
  "help/:page":         "help",
  "download/*path":     "download",
  "folder/:name":       "openFolder",
  "folder/:name-:mode": "openFolder"
}

router.on("route:help", function(page) {
  ...
});

When creating a new router, you may pass its routes hash directly as the routes option, if you choose. All options will also be passed to your initialize function, if defined.

Manually create a route for the router, The route argument may be a routing string or regular expression. Each matching capture from the route or regular expression will be passed as an argument to the callback. The name argument will be triggered as a "route:name" event whenever the route is matched. If the callback argument is omitted router[name] will be used instead. Routes added later may override previously declared routes.

initialize: function(options) {

  // Matches #page/10, passing "10"
  this.route("page/:number", "page", function(number){ ... });

  // Matches /117-a/b/c/open, passing "117-a/b/c" to this.open
  this.route(/^(.*?)\/open$/, "open");

},

open: function(id) { ... }

Whenever you reach a point in your application that you'd like to save as a URL, call navigate in order to update the URL. Route function will be called by default, but if you want to prevent it, you can set the trigger option to false. To update the URL without creating an entry in the browser's history, set the replace option to true.

openPage: function(pageNumber) {
  this.document.pages.at(pageNumber).open();
  this.navigate("page/" + pageNumber);
}

// Or ...

app.navigate("help/troubleshooting", {trigger: false});

// Or ...

app.navigate("help/troubleshooting", {replace: true});

Allows you to re-navigate to the same page. Re-runs the route handler for the current url.

Sometimes you want to be able to redirect to a different route in your application without adding an entry in the browser's history. RedirectTo is just a shorthand for calling navigate with both trigger and replace set to true.

var AppRouter = AmpersandRouter.extend({
    routes: {
        'login': 'login',
        'dashboard': 'dashboard'
    },

    dashboard: function () {
        if (!app.me.loggedIn) return this.redirectTo('login');

        // show dashboard page...
    }
});

This method is called internally within the router, whenever a route matches and its corresponding callback is about to be executed. Override it to perform custom parsing or wrapping of your routes, for example, to parse query strings before handing them to your route callback, like so:

var Router = AmpersandRouter.extend({
  execute: function(callback, args) {
    args.push(parseQueryString(args.pop()));
    if (callback) callback.apply(this, args);
  }
});

AmpersandRouter automatically requires and instantiates a single ampersand-history object. AmpersandHistory serves as a global router (per frame) to handle hashchange events or pushState, match the appropriate route, and trigger callbacks. You shouldn't ever have to create one of these yourself since ampersand-router already contains one.

When all of your Routers have been created, and all of the routes are set up properly, call router.history.start() on one of your routers to begin monitoring hashchange events, and dispatching routes. Subsequent calls to history.start() will throw an error, and router.history.started() is a boolean value indicating whether it has already been called.

Supported options:

• pushState {Boolean} - HTML5 pushState is turned on by default. However if you want to indicate that you don't want to use it in your application, you can add {pushState: false} to the options. Defaults to true
• hashChange {Boolean} - If you'd like to use pushState, but have browsers that don't support it natively use full page refreshes instead, you can add {hashChange: false} to the options. Defaults to true
• root {String} - If your application is not being served from the root url / of your domain, be sure to tell History where the root really is, as an option: router.history.start({root: "/public/search/"}). Defaults to /
• silent {Boolean} - If the server has already rendered the entire page, and you don't want the initial route to trigger when starting History, pass silent: true. Defaults to false

When called, if a route succeeds with a match for the current URL, router.history.start() returns true. If no defined route matches the current URL, it returns false.

All credit goes to Jeremy Ashkenas and the rest of the Backbone.js authors.

If you like this follow @HenrikJoreteg on twitter.

MIT