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@workInProgress
@ngdoc overview
@name Developer Guide: DI: Using DI in Controllers
@description
The most common place to use dependency injection in angular applications is in {@link
dev_guide.mvc.understanding_controller controllers}. Here is a simple example:
<pre>
function MyController($route){
// configure the route service
$route.when(...);
}
MyController.$inject = ['$route'];
</pre>
In this example, the `MyController` constructor function takes one argument, the {@link
api/angular.service.$route $route} service. Angular is then responsible for supplying the instance
of `$route` to the controller when the constructor is instantiated. There are two ways to cause
controller instantiation – by configuring routes with the `$route` service, or by referencing the
controller from the HTML template, as follows:
<pre>
<!doctype html>
<html xmlns:ng="http://angularjs.org" ng:controller="MyController">
<script src="http://code.angularjs.org/angular.min.js" ng:autobind></script>
<body>
...
</body>
</html>
</pre>
When angular is instantiating your controller, it needs to know what services, if any, should be
injected (passed in as arguments) into the controller. Since there is no reflection in JavaScript,
we have to supply this information to angular in the form of an additional property on the
controller constructor function called `$inject`. Think of it as annotations for JavaScript.
<pre>
MyController.$inject = ['$route'];
</pre>
The information in `$inject` is then used by the {@link api/angular.injector injector} to call the
function with the correct arguments.
## Related Topics
* {@link dev_guide.di About Dependency Injection}
* {@link dev_guide.di.understanding_di Understanding Dependency Injection in Angular}
* {@link dev_guide.services Angular Services}
## Related API
* {@link api/angular.injector Angular Injector API}
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