https://auladigital.ieepo.gob.mx/apps/utilidades/app/scripts/directives/preloader.js

1'use strict';
2/*
3 * preloader - loading indicator directive
4 */
5function preloader($rootScope, $timeout) {
6  return {
7    restrict: 'EA',
8    link: function(scope, element) {
9      $rootScope.$on('$stateChangeStart', function() {
10        $timeout(function() {
11          element.removeClass('ng-hide');
12        });
13      });
14      $rootScope.$on('$stateChangeSuccess', function() {
15        $rootScope.$watch('$viewContentLoaded', function() {
16          $timeout(function() {
17            element.addClass('ng-hide');
18          }, 1500);
19        });
20      });
21    }
22  };
23}
24angular.module('app').directive('preloader', preloader);