Defining Your Routes

The 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.

Router.map(function() {
  this.route('about', { path: '/about' });
  this.route('favorites', { path: '/favs' });
});

Now, when the user visits /about, Ember will render the about template. Visiting /favs will render the favorites template.

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:

Router.map(function() {
  this.route('about');
  this.route('favorites', { path: '/favs' });
});

Inside your templates, you can use <LinkTo /> to navigate between routes, using the name that you provided to the route method.

<LinkTo @route="index">
  <img class="logo">
</LinkTo>

<nav>
  <LinkTo @route="about">About</LinkTo>
  <LinkTo @route="favorites">Favorites</LinkTo>
</nav>

The <LinkTo /> component will also add an active class to the link that points to the currently active route.

Multi-word route names are conventionally dasherized, such as:

Router.map(function() {
  this.route('blog-post', { path: '/blog-post' });
});

The route defined above will by default use the blog-post.js route handler, the blog-post.hbs template, and be referred to as blog-post in any <LinkTo /> components.

Multi-word route names that break this convention, such as:

Router.map(function() {
  this.route('blog_post', { path: '/blog-post' });
});

will still by default use the blog-post.js route handler and the blog-post.hbs template, but will be referred to as blog_post in any <LinkTo /> components.

Often you'll want to have a template that displays inside another template. For example, in a blogging application, instead of going from a list of blog posts to creating a new post, you might want to have the post creation page display next to the list.

In these cases, you can use nested routes to display one template inside of another.

You can define nested routes by passing a callback to this.route:

Router.map(function() {
  this.route('posts', function() {
    this.route('new');
  });
});

Assuming you have already generated the posts route, to generate the above nested route you would run:

ember generate route posts/new

And then add the {{outlet}} helper to your template where you want the nested template to display. You can also add a page title with the current page name (using page-title helper), this will help users with assistive technology know where they are in the website.

{{page-title "Posts - Site Title"}}
<h1>Posts</h1>
{{!-- Display posts and other content --}}
{{outlet}}

This generates a route for /posts and for /posts/new. When a user visits /posts, they'll simply see the posts.hbs template. (Below, index routes explains an important addition to this.) When the user visits posts/new, they'll see the posts/new.hbs template rendered into the {{outlet}} of the posts template.

A nested route name includes the names of its ancestors. If you want to transition to a route (either via transitionTo or <LinkTo />), make sure to use the full route name (posts.new, not new).

The application route is entered when your app first boots up. Like other routes, it will load a template with the same name (application in this case) by default. You should put your header, footer, and any other decorative content here. All other routes will render their templates into the application.hbs template's {{outlet}}.

This route is part of every application, so you don't need to specify it in your app/router.js.

At every level of nesting (including the top level), Ember automatically provides a route for the / path named index. To see when a new level of nesting occurs, check the router, whenever you see a function, that's a new level.

For example, if you write a simple router like this:

Router.map(function() {
  this.route('favorites');
});

It is the equivalent of:

Router.map(function() {
  this.route('index', { path: '/' });
  this.route('favorites');
});

The index template will be rendered into the {{outlet}} in the application template. If the user navigates to /favorites, Ember will replace the index template with the favorites template.

A nested router like this:

Router.map(function() {
  this.route('posts', function() {
    this.route('favorites');
  });
});

Is the equivalent of:

Router.map(function() {
  this.route('index', { path: '/' });
  this.route('posts', function() {
    this.route('index', { path: '/' });
    this.route('favorites');
  });
});

Likewise, if the user navigates to /posts, the current route will be posts.index, and the posts/index template will be rendered into the {{outlet}} of the posts template.

If the user then navigates to /posts/favorites, Ember will replace the {{outlet}} in the posts template with the posts/favorites template.

The following scenarios may help with understanding the index route:

• The top-level index route is analogous to index.html. For example, when someone visits https://some-ember-app.com, the contents of the template/index.hbs file will be rendered. There is no need to add an entry this.route('index', { path: '/' }); in app/router.js file. The index route is implicitly included in order to help reduce verbose declarations in the app/router.js. The app/router.js file could be empty, and the index would still be shown:

Router.map(function() {
});

• When a user navigates to /posts, the contents of index.hbs will be rendered. This is similar to a user navigating to the child route of /posts. /posts/index is a child route like /posts/comments or /posts/likes.

The index route is most helpful for rendering a view when the route has dynamic segments defined in it or there are nested routes. In other words, an index template is used to show content that should not be present on sibling and child routes. For example, a blog app might have an index route that shows a list of all posts, but if a user clicks on a post, they should only see the content for the individual post. Here is how that looks in practice:

A templates/posts.hbs file has the following:

{{page-title "Posts"}}
<h1>This is the posts template, containing headers to show on all child routes</h1>
{{outlet}}

The templates/posts/index.hbs file has the following:

{{page-title "Posts"}}
<p>This is the posts/index template with a list of posts</p>

The templates/posts/post.hbs file has the following:

{{page-title "Post"}}
<p>This is an individual post, from the posts/post template, used when we enter the /posts/:post_id route</p>

This is equivalent to having the following entry in app/router.js file

Router.map(function() {
  this.route('posts', function() {
    this.route('post', { path: '/:post_id' });
    this.route('index', { path: '/' });
  })
});

When the user navigates to /posts/123, the following markup will be seen:

{{page-title "Posts"}}
<h1>This is the posts template, containing headers to show on all child routes</h1>
<p>This is an individual post, from the posts/post template, used when we enter the /posts/:post_id route</p>

When the user navigates to /posts/, the following markup will be seen:

{{page-title "Posts"}}
<h1>This is the posts template, containing headers to show on all child routes</h1>
<p>This is the posts/index template with a list of posts</p>

One of the responsibilities of a route is to load a model.

For example, if we have the route this.route('posts');, our route might load all of the blog posts for the app.

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.

Router.map(function() {
  this.route('posts');
  this.route('post', { path: '/post/:post_id' });
});

If the user navigates to /post/5, the route will then have the post_id of 5 to use to load the correct post. Ember follows the convention of :model-name_id for two reasons. The first reason is that Routes know how to fetch the right model by default, if you follow the convention. The second is that params is an object, and can only have one value associated with a key. To put it in code, the following will not work properly:

// This won't work! The dynamic segments will collide.
Router.map(function() {
  this.route('photo', { path: '/photo/:id' }, function() {
    this.route('comment', { path: '/comment/:id' });
  });
});

But the following will:

Router.map(function() {
  this.route('photo', { path: '/photo/:photo_id' }, function() {
    this.route('comment', { path: '/comment/:comment_id' });
  });
});

In the next section, Specifying a Route's Model, you will learn more about how to load a model.

You can define wildcard routes that will match multiple URL segments. This could be used, for example, if you'd like a catch-all route which is useful when the user enters an incorrect URL not managed by your app. Wildcard routes begin with an asterisk.

Router.map(function() {
  this.route('not-found', { path: '/*path' });
});

{{page-title "Not found"}}
<p>Oops, the page you're looking for wasn't found</p>

In the above example we have successfully used a wildcard route to handle all routes not managed by our application so that when a user navigates to /a/non-existent/path they will be shown a message that says the page they're looking for wasn't found.

Note that if you want to manually transition to this wildcard route, you need to pass an arbitrary (not empty) argument. For example, using Ember Data to find a record:

import Route from '@ember/routing/route';
import { inject as service } from '@ember/service';
import { action } from '@ember/object';

export default class SomeRouteRoute extends Route {
  @service store;
  @service router;
  // …
  @action
  async visitUserProfile(id) {
    this.store.findRecord('user', id).then(function (user) {
      // Success callback
      this.router.transitionTo('user.profile', user);
    }).catch(function () {
      // Error callback
      this.router.transitionTo('not-found', 404);
    }
  }
}

To have your route do something beyond render a template with the same name, you'll need to create a route handler. The following guides will explore the different features of route handlers. For more information on routes, see the API documentation for the router and for route handlers.

Once the routes are defined, how do we go about transitioning between them within our application? It depends on where the transition needs to take place:

• From a template, use <LinkTo /> as mentioned above
• From anywhere else in your application, such as a component, inject the Router Service and use the transitionTo() method