问AngularJS：如何看服务变量？

factory('aService', ['$rootScope', '$resource', function ($rootScope, $resource) {

  var service = {

    foo: []

  };

  return service;

}]);

<div ng-controller="FooCtrl">

  <div ng-repeat="item in foo">{{ item }}</div>

</div>

function FooCtrl($scope, aService) {                                                                                                                              

  $scope.aService = aService;

  $scope.foo = aService.foo;

  $scope.$watch('aService.foo', function (newVal, oldVal, scope) {

    if(newVal) { 

      scope.foo = newVal;

    }

  });

}