title: How to inject a controller to a directive in another module
body: <p>I have a module 'paramApp' with controller 'ParamCtrl':</p>
  
  <pre><code>var app = angular.app('paramApp', []);
  
  app.controller('ParamCtrl', ['$scope', '$http', function($scope, $http) {
     .
     .
     .
  }]);
  </code></pre>
  
  <p>I have another module 'deviceApp' with directive 'DeviceDirective':</p>
  
  <pre><code>var app2 = angular.app('deviceApp', []);
  
  app2.directive('DeviceDirective', function() {
  
      return {
          .
          .
          .
          controller: // I want to reference ParamCtrl here
          controllerAs: param
      };
  
  });
  </code></pre>
  
  <p>I read somewhere that I need to use angular.injector (or $injector) to inject the controller, but I'm not so sure how to use it. My attempts to use the injector didn't work. </p>
  
  <p>Is this approach right? Do I need to declare 'paramApp' in 'deviceApp' declaration like this, </p>
  
  <pre><code>var app2 = angular.app('deviceApp', ['paramApp']);
  </code></pre>
  
  <p>Please help on how to use injector in the directive controller to reference another module's controller.</p>