When your application starts, the router is responsible for displaying templates, loading data, and otherwise setting up application state. It does so by matching the current URL to the _routes_ that you've defined. The [map](http://emberjs.com/api/classes/Ember.Router.html#method_map) method of your Ember application's router can be invoked to define URL mappings. When calling `map`, you should pass a function that will be invoked with the value `this` set to an object which you can use to create [routes](http://emberjs.com/guides/routing/defining-your-routes/) and [resources](http://emberjs.com/guides/routing/defining-your-routes/#toc_resources). ```javascript App.Router.map(function() { this.route('about', { path: '/about' }); this.route('favorites', { path: '/favs' }); }); ``` Now, when the user visits `/about`, Ember.js will render the `about` template. Visiting `/favs` will render the `favorites` template. **Heads up!** You get a few routes for free: the `ApplicationRoute` and the `IndexRoute` (corresponding to the `/` path). [See below](#toc_initial-routes) for more details. Note that you can leave off the path if it is the same as the route name. In this case, the following is equivalent to the above example: ```javascript App.Router.map(function() { this.route('about'); this.route('favorites', { path: '/favs' }); }); ``` Inside your templates, you can use `{{link-to}}` to navigate between routes, using the name that you provided to the `route` method (or, in the case of `/`, the name `index`). ```handlebars {{#link-to 'index'}}{{/link-to}} ``` The `{{link-to}}` helper will also add an `active` class to the link that points to the currently active route. You can customize the behavior of a route by creating an `Ember.Route` subclass. For example, to customize what happens when your user visits `/`, create an `App.IndexRoute`: ```javascript App.IndexRoute = Ember.Route.extend({ setupController: function(controller) { // Set the IndexController's `title` controller.set('title', 'My App'); } }); ``` The `IndexController` is the starting context for the `index` template. Now that you've set `title`, you can use it in the template: ```handlebars

{{title}}

``` (If you don't explicitly define an `App.IndexController`, Ember.js will automatically generate one for you.) Ember.js automatically figures out the names of the routes and controllers based on the name you pass to `this.route`.
URL Route Name Controller Route Template
/ index IndexController IndexRoute index
/about about AboutController AboutRoute about
/favs favorites FavoritesController FavoritesRoute favorites
### Resources You can define groups of routes that work with a resource: ```javascript App.Router.map(function() { this.resource('posts', { path: '/posts' }, function() { this.route('new'); }); }); ``` As with `this.route`, you can leave off the path if it's the same as the name of the route, so the following router is equivalent: ```javascript App.Router.map(function() { this.resource('posts', function() { this.route('new'); }); }); ``` This router creates three routes:
URL Route Name Controller Route Template
/ index IndexController IndexRoute index
N/A posts1 PostsController PostsRoute posts
/posts posts.index PostsController
↳PostsIndexController		 PostsRoute
↳PostsIndexRoute		 posts
↳posts/index
/posts/new posts.new PostsController
↳PostsNewController		 PostsRoute
↳PostsNewRoute		 posts
↳posts/new
1 Transitioning to `posts` or creating a link to `posts` is equivalent to transitioning to `posts.index` or linking to `posts.index` NOTE: If you define a resource using `this.resource` and **do not** supply a function, then the implicit `resource.index` route is **not** created. In that case, `/resource` will only use the `ResourceRoute`, `ResourceController`, and `resource` template. Routes nested under a resource take the name of the resource plus their name as their route name. If you want to transition to a route (either via `transitionTo` or `{{#link-to}}`), make sure to use the full route name (`posts.new`, not `new`). Visiting `/` renders the `index` template, as you would expect. Visiting `/posts` is slightly different. It will first render the `posts` template. Then, it will render the `posts/index` template into the `posts` template's outlet. Finally, visiting `/posts/new` will first render the `posts` template, then render the `posts/new` template into its outlet. NOTE: You should use `this.resource` for URLs that represent a **noun**, and `this.route` for URLs that represent **adjectives** or **verbs** modifying those nouns. For example, in the code sample above, when specifying URLs for posts (a noun), the route was defined with `this.resource('posts')`. However, when defining the `new` action (a verb), the route was defined with `this.route('new')`. ### Multi-word Model Names For multi-word models all the names are camel cased except for the dynamic segment. For example, a model named `BigMac` would have a resource path of `/bigMacs/:big_mac_id`, route named `bigMac`, template named `bigMac`. ### Dynamic Segments One of the responsibilities of a resource's route handler is to convert a URL into a model. For example, if we have the resource `this.resource('posts');`, our route handler might look like this: ```javascript App.PostsRoute = Ember.Route.extend({ model: function() { return this.store.find('post'); } }); ``` The `posts` template will then receive a list of all available posts as its context. Because `/posts` represents a fixed model, we don't need any additional information to know what to retrieve. However, if we want a route to represent a single post, we would not want to have to hardcode every possible post into the router. Enter _dynamic segments_. A dynamic segment is a portion of a URL that starts with a `:` and is followed by an identifier. ```javascript App.Router.map(function() { this.resource('posts'); this.resource('post', { path: '/post/:post_id' }); }); App.PostRoute = Ember.Route.extend({ model: function(params) { return this.store.find('post', params.post_id); } }); ``` Because this pattern is so common, the above `model` hook is the default behavior. For example, if the dynamic segment is `:post_id`, Ember.js is smart enough to know that it should use the model `App.Post` (with the ID provided in the URL). Specifically, unless you override `model`, the route will return `this.store.find('post', params.post_id)` automatically. Not coincidentally, this is exactly what Ember Data expects. So if you use the Ember router with Ember Data, your dynamic segments will work as expected out of the box. If your model does not use the `id` property in the URL, you should define a serialize method on your route: ```javascript App.Router.map(function() { this.resource('post', {path: '/posts/:post_slug'}); }); App.PostRoute = Ember.Route.extend({ model: function(params) { // the server returns `{ slug: 'foo-post' }` return Ember.$.getJSON('/posts/' + params.post_slug); }, serialize: function(model) { // this will make the URL `/posts/foo-post` return { post_slug: model.get('slug') }; } }); ``` The default `serialize` method inserts the model's `id` into the route's dynamic segment (in this case, `:post_id`). ### Nested Resources You can nest both routes and resources: ```javascript App.Router.map(function() { this.resource('post', { path: '/post/:post_id' }, function() { this.route('edit'); this.resource('comments', function() { this.route('new'); }); }); }); ``` This router creates five routes:
URL Route Name Controller Route Template
/ index App.IndexController App.IndexRoute index
N/A post App.PostController App.PostRoute post
/post/:post_id2 post.index App.PostIndexController App.PostIndexRoute post/index
/post/:post_id/edit post.edit App.PostEditController App.PostEditRoute post/edit
N/A comments App.CommentsController App.CommentsRoute comments
/post/:post_id/comments comments.index App.CommentsIndexController App.CommentsIndexRoute comments/index
/post/:post_id/comments/new comments.new App.CommentsNewController App.CommentsNewRoute comments/new
2 `:post_id` is the post's id. For a post with id = 1, the route will be: `/post/1` The `comments` template will be rendered in the `post` outlet. All templates under `comments` (`comments/index` and `comments/new`) will be rendered in the `comments` outlet. The route, controller, and view class names for the comments resource are not prefixed with `Post`. Resources always reset the namespace, ensuring that the classes can be re-used between multiple parent resources and that class names don't get longer the deeper nested the resources are. You are also able to create deeply nested resources in order to preserve the namespace on your routes: ```javascript App.Router.map(function() { this.resource('foo', function() { this.resource('foo.bar', { path: '/bar' }, function() { this.route('baz'); // This will be foo.bar.baz }); }); }); ``` This router creates the following routes:
URL Route Name Controller Route Template
/ index App.IndexController App.IndexRoute index
/foo foo.index App.FooIndexController App.FooIndexRoute foo/index
/foo/bar foo.bar.index App.FooBarIndexController App.FooBarIndexRoute foo/bar/index
/foo/bar/baz foo.bar.baz App.FooBarBazController App.FooBarBazRoute foo/bar/baz
### Initial routes A few routes are immediately available within your application: - `App.ApplicationRoute` is entered when your app first boots up. It renders the `application` template. - `App.IndexRoute` is the default route, and will render the `index` template when the user visits `/` (unless `/` has been overridden by your own custom route). Remember, these routes are part of every application, so you don't need to specify them in `App.Router.map`. ### Wildcard / globbing routes You can define wildcard routes that will match multiple routes. This could be used, for example, if you'd like a catchall route which is useful when the user enters an incorrect URL not managed by your app. ```javascript App.Router.map(function() { this.route('catchall', {path: '/*wildcard'}); }); ``` Like all routes with a dynamic segment, you must provide a context when using a `{{link-to}}` or `transitionTo` to programatically enter this route. ```javascript App.ApplicationRoute = Ember.Route.extend({ actions: { error: function() { this.transitionTo('catchall', 'application-error'); } } }); ``` With this code, if an error bubbles up to the Application route, your application will enter the `catchall` route and display `/application-error` in the URL.