I have got a controller named newGroupCtrl whose definition is like :

```
.state('new_group', {
    url: '/new_group',
    templateUrl: 'templates/new_group.html',
    controller: 'newGroupCtrl'
})

.controller('newGroupCtrl', function ($scope, $rootScope,$ionicHistory,$window) {
    $rootScope.roomId = $scope.getRoom();

    $scope.getRoom = function () {
        var date = new Date;
        var minutes = date.getMinutes();
        var hour = date.getHours();
        return 'room_' + hour + '' + minutes;
    };
}

```

I reach this contoller from previous page by :

```
$window.location.href = ('#/new_group');

```

That's good until now. `$rootScope.roomId` variable is initialized in the newGroupCtrl controller properly.

From this new\_group page, I navigate to another page. And when I navigate back to this page by calling `$window.location.href = ('#/new_group');`,
 `$rootScope.roomId` is not initialized again, instead its old value is still there. The state of the newGroupCtrl is preserved. 

How can I completely reinitialize newGroupCtrl?