An AngularJS directive called InfiniteScroll; Infinite Scrolling mechanism is used in lazy loading. It gets a callback handler which then gets called when scrolling has reached to the bottom of the element.

InfiniteScroll.js

/**
 * InfiniteScroll is a AngularJS directive.
 * This directive calls your callback function when scrolling of an element is reached to the bottom.
 */
'use strict';
angular.module('InfiniteScroll', []).directive('infiniteScroll', function () {
  return {
    restrict: 'A',
    scope: {
      callback: '&infiniteScroll'
    },
    link: function($scope, iElem, iAttr){

      /**
       * Scroll callback event handler.
       * @param  {[type]} e [description]
       * @return {[type]}   [description]
       */
      var _scrollHandler = function (e) {
        if((e.target.scrollTop + e.target.clientHeight) >= e.target.scrollHeight){
         $scope.callback({$event: e});
        }
      };

      /**
       * Attach the Scroll event to the element.
       */
      iElem.on('scroll', _scrollHandler);

      /**
       * Unbind the scroll event when the scope is destroyed.
       * @return {[type]} [description]
       */
      $scope.$on('$destroy', function () {
        iElem.off('scroll', _scrollHandler);
      });
    }
  };
});