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+@ngdoc overview
+@name Controllers
+@description
+
+# Understanding Controllers
+
+In Angular, a Controller is a JavaScript **constructor function** that is used to augment the
+{@link scope Angular Scope}.
+
+When a Controller is attached to the DOM via the {@link api/ng.directive:ngController ng-controller}
+directive, Angular will instantiate a new Controller object, using the specified Controller's
+**constructor function**. A new **child scope** will be available as an injectable parameter to the
+Controller's constructor function as `$scope`.
+
+Use Controllers to:
+
+- Set up the initial state of the `$scope` object.
+- Add behavior to the `$scope` object.
+
+# Setting up the initial state of a `$scope` object
+
+Typically, when you create an application you need to set up the initial state for the Angular
+`$scope`. You set up the initial state of a scope by attaching properties to the `$scope` object.
+The properties contain the **view model** (the model that will be presented by the view). All the
+`$scope` properties will be available to the template at the point in the DOM where the Controller
+is registered.
+
+The following example shows a very simple constructor function for a Controller, `GreetingCtrl`,
+which attaches a `greeting` property containing the string `'Hola!'` to the `$scope`:
+
+<pre>
+ function GreetingCtrl($scope) {
+ $scope.greeting = 'Hola!';
+ }
+</pre>
+
+Once the Controller has been attached to the DOM, the `greeting` property can be data-bound to the
+template:
+
+<pre>
+ <div ng-controller="GreetingCtrl">
+ {{ greeting }}
+ </div>
+</pre>
+
+**NOTE**: Although Angular allows you to create Controller functions in the global scope, this is
+not recommended. In a real application you should use the `.controller` method of your
+{@link module Angular Module} for your application as follows:
+
+<pre>
+ var myApp = angular.module('myApp',[]);
+
+ myApp.controller('GreetingCtrl', ['$scope', function($scope) {
+ $scope.greeting = 'Hola!';
+ }]);
+</pre>
+
+We have used an **inline injection annotation** to explicitly specify the dependency
+of the Controller on the `$scope` service provided by Angular. See the guide on
+{@link http://docs.angularjs.org/guide/di Dependency Injection} for more information.
+
+
+# Adding Behavior to a Scope Object
+
+In order to react to events or execute computation in the view we must provide behavior to the
+scope. We add behavior to the scope by attaching methods to the `$scope` object. These methods are
+then available to be called from the template/view.
+
+The following example uses a Controller to add a method to the scope, which doubles a number:
+
+<pre>
+ var myApp = angular.module('myApp',[]);
+
+ myApp.controller('DoubleCtrl', ['$scope', function($scope) {
+ $scope.double = function(value) { return value * 2; };
+ }]);
+</pre>
+
+Once the Controller has been attached to the DOM, the `double` method can be invoked in an Angular
+expression in the template:
+
+<pre>
+ <div ng-controller="DoubleCtrl">
+ Two times <input ng-model="num"> equals {{ double(num) }}
+ </div>
+</pre>
+
+As discussed in the {@link concepts Concepts} section of this guide, any
+objects (or primitives) assigned to the scope become model properties. Any methods assigned to
+the scope are available in the template/view, and can be invoked via angular expressions
+and `ng` event handler directives (e.g. {@link api/ng.directive:ngClick ngClick}).
+
+# Using Controllers Correctly
+
+In general, a Controller shouldn't try to do too much. It should contain only the business logic
+needed for a single view.
+
+The most common way to keep Controllers slim is by encapsulating work that doesn't belong to
+controllers into services and then using these services in Controllers via dependency injection.
+This is discussed in the {@link di Dependency Injection} {@link dev_guide.services
+Services} sections of this guide.
+
+Do not use Controllers for:
+
+- Any kind of DOM manipulation — Controllers should contain only business logic. DOM
+manipulation (the presentation logic of an application) is well known for being hard to test.
+Putting any presentation logic into Controllers significantly affects testability of the business
+logic. Angular offers {@link databinding databinding} for automatic DOM manipulation. If
+you have to perform your own manual DOM manipulation, encapsulate the presentation logic in
+{@link guide/directive directives}.
+- Input formatting — Use {@link forms angular form controls} instead.
+- Output filtering — Use {@link dev_guide.templates.filters angular filters} instead.
+- Sharing stateless or stateful code across Controllers — Use {@link dev_guide.services angular
+services} instead.
+- Managing the life-cycle of other components (for example, to create service instances).
+
+
+# Associating Controllers with Angular Scope Objects
+
+You can associate Controllers with scope objects implicitly via the {@link api/ng.directive:ngController ngController
+directive} or {@link api/ngRoute.$route $route service}.
+
+
+## Simple Spicy Controller Example
+
+To illustrate further how Controller components work in Angular, let's create a little app with the
+following components:
+
+- A {@link templates template} with two buttons and a simple message
+- A model consisting of a string named `spice`
+- A Controller with two functions that set the value of `spice`
+
+The message in our template contains a binding to the `spice` model, which by default is set to the
+string "very". Depending on which button is clicked, the `spice` model is set to `chili` or
+`jalapeño`, and the message is automatically updated by data-binding.
+
+<doc:example module="spicyApp1">
+ <doc:source>
+ <div ng-app="spicyApp1" ng-controller="SpicyCtrl">
+ <button ng-click="chiliSpicy()">Chili</button>
+ <button ng-click="jalapenoSpicy()">Jalapeño</button>
+ <p>The food is {{spice}} spicy!</p>
+ </div>
+ <script>
+ var myApp = angular.module('spicyApp1', []);
+
+ myApp.controller('SpicyCtrl', ['$scope', function($scope){
+ $scope.spice = 'very';
+
+ $scope.chiliSpicy = function() {
+ $scope.spice = 'chili';
+ };
+
+ $scope.jalapenoSpicy = function() {
+ $scope.spice = 'jalapeño';
+ };
+ }]);
+ </script>
+ </doc:source>
+</doc:example>
+
+Things to notice in the example above:
+
+- The `ng-controller` directive is used to (implicitly) create a scope for our template, and the
+scope is augmented (managed) by the `SpicyCtrl` Controller.
+- `SpicyCtrl` is just a plain JavaScript function. As an (optional) naming convention the name
+starts with capital letter and ends with "Ctrl" or "Controller".
+- Assigning a property to `$scope` creates or updates the model.
+- Controller methods can be created through direct assignment to scope (see the `chiliSpicy` method)
+- The Controller methods and properties are available in the template (for the `<div>` element and
+and its children).
+
+## Spicy Arguments Example
+
+Controller methods can also take arguments, as demonstrated in the following variation of the
+previous example.
+
+<doc:example module="spicyApp2">
+ <doc:source>
+ <div ng-app="spicyApp2" ng-controller="SpicyCtrl">
+ <input ng-model="customSpice">
+ <button ng-click="spicy('chili')">Chili</button>
+ <button ng-click="spicy(customSpice)">Custom spice</button>
+ <p>The food is {{spice}} spicy!</p>
+ </div>
+ <script>
+ var myApp = angular.module('spicyApp2', []);
+
+ myApp.controller('SpicyCtrl', ['$scope', function($scope){
+ $scope.customSpice = "wasabi";
+ $scope.spice = 'very';
+
+ $scope.spicy = function(spice){
+ $scope.spice = spice;
+ };
+ }]);
+ </script>
+</doc:source>
+</doc:example>
+
+Notice that the `SpicyCtrl` Controller now defines just one method called `spicy`, which takes one
+argument called `spice`. The template then refers to this Controller method and passes in a string
+constant `'chili'` in the binding for the first button and a model property `spice` (bound to an
+input box) in the second button.
+
+## Scope Inheritance Example
+
+It is common to attach Controllers at different levels of the DOM hierarchy. Since the
+{@link api/ng.directive:ngController ng-controller} directive creates a new child scope, we get a
+hierarchy of scopes that inherit from each other. The `$scope` that each Controller receives will
+have access to properties and methods defined by Controllers higher up the hierarchy.
+See {@link https://github.com/angular/angular.js/wiki/Understanding-Scopes Understanding Scopes} for
+more information about scope inheritance.
+
+<doc:example module="scopeInheritance">
+ <doc:source>
+ <div ng-app="scopeInheritance" class="spicy">
+ <div ng-controller="MainCtrl">
+ <p>Good {{timeOfDay}}, {{name}}!</p>
+
+ <div ng-controller="ChildCtrl">
+ <p>Good {{timeOfDay}}, {{name}}!</p>
+
+ <div ng-controller="GrandChildCtrl">
+ <p>Good {{timeOfDay}}, {{name}}!</p>
+ </div>
+ </div>
+ </div>
+ </div>
+ <style>
+ div.spicy div {
+ padding: 10px;
+ border: solid 2px blue;
+ }
+ </style>
+ <script>
+ var myApp = angular.module('scopeInheritance', []);
+ myApp.controller('MainCtrl', ['$scope', function($scope){
+ $scope.timeOfDay = 'morning';
+ $scope.name = 'Nikki';
+ }]);
+ myApp.controller('ChildCtrl', ['$scope', function($scope){
+ $scope.name = 'Mattie';
+ }]);
+ myApp.controller('GrandChildCtrl', ['$scope', function($scope){
+ $scope.timeOfDay = 'evening';
+ $scope.name = 'Gingerbreak Baby';
+ }]);
+ </script>
+ </doc:source>
+</doc:example>
+
+Notice how we nested three `ng-controller` directives in our template. This will result in four
+scopes being created for our view:
+
+- The root scope
+- The `MainCtrl` scope, which contains `timeOfDay` and `name` properties
+- The `ChildCtrl` scope, which inherits the `timeOfDay` property but overrides (hides) the `name`
+property from the previous
+- The `GrandChildCtrl` scope, which overrides (hides) both the `timeOfDay` property defined in `MainCtrl`
+and the `name` property defined in `ChildCtrl`
+
+Inheritance works with methods in the same way as it does with properties. So in our previous
+examples, all of the properties could be replaced with methods that return string values.
+
+
+## Testing Controllers
+
+Although there are many ways to test a Controller, one of the best conventions, shown below,
+involves injecting the {@link api/ng.$rootScope $rootScope} and {@link api/ng.$controller $controller}:
+
+**Controller Definition:**
+<pre>
+ var myApp = angular.module('myApp',[]);
+
+ myApp.controller('MyController', function($scope) {
+ $scope.spices = [{"name":"pasilla", "spiciness":"mild"},
+ {"name":"jalapeno", "spiceiness":"hot hot hot!"},
+ {"name":"habanero", "spiceness":"LAVA HOT!!"}];
+ $scope.spice = "habanero";
+ });
+</pre>
+
+**Controller Test:**
+<pre>
+describe('myController function', function() {
+
+ describe('myController', function() {
+ var $scope;
+
+ beforeEach(module('myApp'));
+
+ beforeEach(inject(function($rootScope, $controller) {
+ $scope = $rootScope.$new();
+ $controller('MyController', {$scope: $scope});
+ }));
+
+ it('should create "spices" model with 3 spices', function() {
+ expect($scope.spices.length).toBe(3);
+ });
+
+ it('should set the default value of spice', function() {
+ expect($scope.spice).toBe('habanero');
+ });
+ });
+});
+</pre>
+
+
+If you need to test a nested Controller you need to create the same scope hierarchy
+in your test that exists in the DOM:
+
+<pre>
+describe('state', function() {
+ var mainScope, childScope, grandChildScope;
+
+ beforeEach(module('myApp'));
+
+ beforeEach(inject(function($rootScope, $controller) {
+ mainScope = $rootScope.$new();
+ $controller('MainCtrl', {$scope: mainScope});
+ childScope = mainScope.$new();
+ $controller('ChildCtrl', {$scope: childScope});
+ grandChildScope = childScope.$new();
+ $controller('GrandChildCtrl', {$scope: grandChildScope});
+ }));
+
+ it('should have over and selected', function() {
+ expect(mainScope.timeOfDay).toBe('morning');
+ expect(mainScope.name).toBe('Nikki');
+ expect(childScope.timeOfDay).toBe('morning');
+ expect(childScope.name).toBe('Mattie');
+ expect(grandChildScope.timeOfDay).toBe('evening');
+ expect(grandChildScope.name).toBe('Gingerbreak Baby');
+ });
+});
+</pre>
+
+
+