## Model and Controller
The data __model__ (a simple array of phones in object literal notation) is now instantiated within
the `PhoneListCtrl` __controller__. The __controller__ is simply a constructor function that takes a
`$scope` parameter:
__`app/js/controllers.js`:__
```js
var phonecatApp = angular.module('phonecatApp', []);
phonecatApp.controller('PhoneListCtrl', function ($scope) {
$scope.phones = [
{'name': 'Nexus S',
'snippet': 'Fast just got faster with Nexus S.'},
{'name': 'Motorola XOOM™ with Wi-Fi',
'snippet': 'The Next, Next Generation tablet.'},
{'name': 'MOTOROLA XOOM™',
'snippet': 'The Next, Next Generation tablet.'}
];
});
```
Here we declared a controller called `PhoneListCtrl` and registered it in an AngularJS
module, `phonecatApp`. Notice that our `ng-app` directive (on the `` tag) now specifies the `phonecatApp`
module name as the module to load when bootstrapping the Angular application.
Although the controller is not yet doing very much, it plays a crucial role. By providing context
for our data model, the controller allows us to establish data-binding between
the model and the view. We connected the dots between the presentation, data, and logic components
as follows:
* The {@link ng.directive:ngController ngController} directive, located on the `` tag,
references the name of our controller, `PhoneListCtrl` (located in the JavaScript file
`controllers.js`).
* The `PhoneListCtrl` controller attaches the phone data to the `$scope` that was injected into our
controller function. This *scope* is a prototypical descendant of the *root scope* that was created
when the application was defined. This controller scope is available to all bindings located within
the `` tag.
### Scope
The concept of a scope in Angular is crucial. A scope can be seen as the glue which allows the
template, model and controller to work together. Angular uses scopes, along with the information
contained in the template, data model, and controller, to keep models and views separate, but in
sync. Any changes made to the model are reflected in the view; any changes that occur in the view
are reflected in the model.
To learn more about Angular scopes, see the {@link ng.$rootScope.Scope angular scope documentation}.
## Tests
The "Angular way" of separating controller from the view, makes it easy to test code as it is being
developed. If our controller is available on the global namespace then we can simply instantiate it
with a mock `scope` object. Take a look at the following unit test for our controller:
__`test/unit/controllersSpec.js`:__
```js
describe('PhoneCat controllers', function() {
describe('PhoneListCtrl', function(){
it('should create "phones" model with 3 phones', function() {
var scope = {},
ctrl = new PhoneListCtrl(scope);
expect(scope.phones.length).toBe(3);
});
});
});
```
The test instantiates `PhoneListCtrl` and verifies that the phones array property on the scope
contains three records. This example demonstrates how easy it is to create a unit test for code in
Angular. Since testing is such a critical part of software development, we make it easy to create
tests in Angular so that developers are encouraged to write them.
### Testing non-Global Controllers
In practice, you will not want to have your controller functions in the global namespace. Instead,
we have registered our controllers in the `phonecatApp` module. In this case Angular provides a
service, `$controller`, which will retrieve your controller by name. Here is the same test using
`$controller`:
__`test/unit/controllersSpec.js`:__
```js
describe('PhoneCat controllers', function() {
beforeEach(module('phonecatApp'));
describe('PhoneListCtrl', function(){
it('should create "phones" model with 3 phones', inject(function($controller) {
var scope = {},
ctrl = $controller('PhoneListCtrl', { $scope: scope });
expect(scope.phones.length).toBe(3);
}));
});
});
```
Don't forget that we need to load up the `phonecatApp` module into the test so that the controller
is available to be injected.
### Writing and Running Tests
Angular developers prefer the syntax of Jasmine's Behavior-driven Development (BDD) framework when
writing tests. Although Angular does not require you to use Jasmine, we wrote all of the tests in
this tutorial in Jasmine. You can learn about Jasmine on the [Jasmine home page](http://jasmine.github.io/) and at the [Jasmine docs](http://jasmine.github.io/).
The angular-seed project is pre-configured to run all unit tests using [Karma](http://karma-runner.github.io/). Ensure that the necessary karma plugins are installed.
You can do this by issuing `npm install` into your terminal.
To run the test, do the following:
1. In a _separate_ terminal window or tab, go to the `angular-phonecat` directory and run
`./scripts/test.sh` (if you are on Windows, run scripts\test.bat) to start the Karma server (the
config file necessary to start the server is located at `./config/karma.conf.js`).
2. Karma will start a new instance of Chrome browser automatically. Just ignore it and let it run in
the background. Karma will use this browser for test execution.
3. You should see the following or similar output in the terminal:
info: Karma server started at http://localhost:9876/
info (launcher): Starting browser "Chrome"
info (Chrome 22.0): Connected on socket id tPUm9DXcLHtZTKbAEO-n
Chrome 22.0: Executed 1 of 1 SUCCESS (0.093 secs / 0.004 secs)
Yay! The test passed! Or not...
4. To rerun the tests, just change any of the source or test .js files. Karma will notice the change
and will rerun the tests for you. Now isn't that sweet?
# Experiments
* Add another binding to `index.html`. For example:
Total number of phones: {{phones.length}}
* Create a new model property in the controller and bind to it from the template. For example: $scope.name = "World"; Then add a new binding to `index.html`:Hello, {{name}}!
Refresh your browser and verify that it says "Hello, World!". * Create a repeater that constructs a simple table:| row number |
|---|
| {{i}} |
| row number |
|---|
| {{i+1}} |