Cannot set a custom bullet render function

[andrepestana]

I'm trying to set a custom renderBullet function:

<section id="main-swipe" class="swipe" ng-controller="SwipeController">
     <swiper pagination-type="bullets" pagination-bullet-render="renderBullet">
       ...
    </swiper>
</section>

module.controller("SwipeController", function($scope) {
  $scope.renderBullet = function (index, className) {
    return '<span class="' + className + '">' + (index + 1) + '</span>';
  };  
});

But I got:

TypeError: x.params.paginationBulletRender is not a function
    at i.x.updatePagination (angular-ui-swiper.min.js:1)

[andrepestana]

Actually I realized that I should use double braces as in:

<section id="main-swipe" class="swipe" ng-controller="SwipeController">
     <swiper pagination-type="bullets" pagination-bullet-render="{{renderBullet}}">
       ...
    </swiper>
</section>

but still the value got in ui-swiper is a string and I get the same error. I'm pulling a request to change the code. Please evaluate the change.