Angular - click child, set class on ng-repeat parent

gistfile1.txt

// Angular ng-repeat and setting class on item from item's child
// Clicking child sends it's parents index to the controller
// Controller toggles the toggleState boolean and the index lets us 
// only add classes to the parent of the clicked child

// in controller
$scope.toggleParentClass = function($index){
  $scope.parentIndex = $index;
  $scope.toggleState = !$scope.toggleState;
};

// in view
<ul>
  <li ng-repeat="item in items" ng-class="{'is-active' : $index==parentIndex && toggleState}">
    <div on-click="toggleParentClass($index)">Click Here</div>
  </li>
</ul>