@ngdoc overview
@name Tutorial: 7 - Routing & Multiple Views
@description

<ul doc:tutorial-nav="7"></ul>


In this step, you will learn how to create a layout template and how to build an app that has
multiple views by adding routing.


<doc:tutorial-instructions step="7"></doc:tutorial-instructions>


Note that you are redirected to `app/index.html#/phones` and the same phone list appears in the
browser. When you click on a phone link the stub of a phone detail page is displayed.


The most important changes are listed below. You can see the full diff on {@link
https://github.com/angular/angular-phonecat/compare/step-6...step-7
GitHub}:


## Multiple Views, Routing and Layout Template

Our app is slowly growing and becoming more complex. Before step 7, the app provided our users with
a single view (the list of all phones), and all of the template code was located in the
`index.html` file. The next step in building the app is to add a view that will show detailed
information about each of the devices in our list.

To add the detailed view, we could expand the `index.html` file to contain template code for both
views, but that would get messy very quickly. Instead, we are going to turn the `index.html`
template into what we call a "layout template". This is a template that is common for all views in
our application. Other "partial templates" are then included into this layout template depending on
the current "route" — the view that is currently displayed to the user.

Application routes in angular are declared via the {@link api/angular.service.$route $route}
service. This service makes it easy to wire together controllers, view templates, and the current
URL location in the browser. Using this feature we can implement {@link
http://en.wikipedia.org/wiki/Deep_linking deep linking}, which lets us utilize the browser's
history (back and forward navigation) and bookmarks.


## Controllers

__`app/js/controller.js`:__
<pre>
function PhoneCatCtrl($route) {
  var self = this;

  $route.when('/phones',
      {template: 'partials/phone-list.html',   controller: PhoneListCtrl});
  $route.when('/phones/:phoneId',
      {template: 'partials/phone-detail.html', controller: PhoneDetailCtrl});
  $route.otherwise({redirectTo: '/phones'});

  $route.onChange(function() {
    self.params = $route.current.params;
  });

  $route.parent(this);
}

//PhoneCatCtrl.$inject = ['$route'];
...
</pre>

We created a new controller called `PhoneCatCtrl`. We declared its dependency on the `$route`
service and used this service to declare that our application consists of two different views:

* The phone list view will be shown when the URL hash fragment is `/phones`. To construct this
view, angular will use the `phone-list.html` template and the `PhoneListCtrl` controller.

* The phone details view will be shown when the URL hash fragment matches '/phone/:phoneId', where
`:phoneId` is a variable part of the URL. To construct the phone details view, angular will use the
`phone-detail.html` template and the `PhoneDetailCtrl` controller.

We reused the `PhoneListCtrl` controller that we constructed in previous steps and we added a new,
empty `PhoneDetailCtrl` controller to the `app/js/controllers.js` file for the phone details view.

The statement `$route.otherwise({redirectTo: '/phones'})` triggers a redirection to `/phones` when
the browser address doesn't match either of our routes.

Thanks to the `$route.parent(this);` statement and `ng:controller="PhoneCatCtrl"` declaration in
the `index.html` template, the `PhoneCatCtrl` controller has a special role in our app. It is the
"root" controller and the parent controller for the other two sub-controllers (`PhoneListCtrl` and
`PhoneDetailCtrl`). The sub-controllers inherit the model properties and behavior from the root
controller.

Note the use of the `:phoneId` parameter in the second route declaration. The `$route` service uses
the route declaration — `'/phones/:phoneId'` — as a template that is matched against the current
URL. All variables defined with the `:` notation are extracted into the `$route.current.params` map.

The `params` alias created in the {@link api/angular.service.$route `$route.onChange`} callback
allows us to use the `phoneId` property of this map in the `phone-details.html` template.


## Template

The `$route` service is usually used in conjunction with the {@link api/angular.widget.ng:view
ng:view} widget. The role of the `ng:view` widget is to include the view template for the current
route into the layout template, which makes it a perfect fit for our `index.html` template.

__`app/index.html`:__
<pre>
...
<body ng:controller="PhoneCatCtrl">

  <ng:view></ng:view>

  <script src="lib/angular/angular.js" ng:autobind></script>
  <script src="js/controllers.js"></script>
</body>
</html>
</pre>

Note that we removed most of the code in the `index.html` template and replaced it with a single
line containing the `ng:view` tag. The code that we removed was placed into the `phone-list.html`
template:

__`app/partials/phone-list.html`:__
<pre>
<ul class="predicates">
  <li>
    Search: <input type="text" name="query"/>
  </li>
  <li>
    Sort by:
    <select name="orderProp">
      <option value="name">Alphabetical</option>
      <option value="age">Newest</option>
    </select>
  </li>
</ul>

<ul class="phones">
  <li ng:repeat="phone in phones.$filter(query).$orderBy(orderProp)">
    <a href="#/phones/{{phone.id}}">{{phone.name}}</a>
    <a href="#/phones/{{phone.id}}" class="thumb"><img ng:src="{{phone.imageUrl}}"></a>
    <p>{{phone.snippet}}</p>
  </li>
</ul>
</pre>

<img src="img/tutorial/tutorial_07_final.png">

We also added a placeholder template for the phone details view:

__`app/partials/phone-detail.html`:__
<pre>
TBD: detail view for {{params.phoneId}}
</pre>

Note how we are using `params` model defined in the `PhoneCatCtrl` controller.


## Test

To automatically verify that everything is wired properly, we wrote end-to-end tests that navigate
to various URLs and verify that the correct view was rendered.

<pre>
...
  it('should redirect index.html to index.html#/phones', function() {
   browser().navigateTo('../../app/index.html');
   expect(browser().location().hash()).toBe('/phones');
  });
...

 describe('Phone detail view', function() {

   beforeEach(function() {
      browser().navigateTo('../../app/index.html#/phones/nexus-s');
   });


   it('should display placeholder page with phoneId', function() {
      expect(binding('params.phoneId')).toBe('nexus-s');
   });
 });
</pre>


You can now refresh the browser tab with the end-to-end test runner to see the tests run, or you
can see them running on {@link
http://angular.github.com/angular-phonecat/step-7/test/e2e/runner.html
angular's server}.


# Experiments

* Try to add an `{{orderProp}}` binding to `index.html`, and you'll see that nothing happens even
when you are in the phone list view. This is because the `orderProp` model is visible only in the
scope managed by `PhoneListCtrl`, which is associated with the `<ng:view>` element. If you add the
same binding into the `phone-list.html` template, the binding will work as expected.

* In `PhoneCatCtrl`, create a new model called "`hero`" with `this.hero = 'Zoro'`. In
`PhoneListCtrl` let's shadow it with `this.hero = 'Batman'`, and in `PhoneDetailCtrl` we'll use
`this.hero = "Captain Proton"`. Then add the `<p>hero = {{hero}}</p>` to all three of our templates
(`index.html`, `phone-list.html`, and `phone-detail.html`). Open the app and you'll see scope
inheritance and model property shadowing do some wonders.

# Summary

With the routing set up and the phone list view implemented, we're ready to go to {@link step_08
step 8} to implement the phone details view.


<ul doc:tutorial-nav="7"></ul>
