angularjs - Open ionicModal on stateChangeStart -

i have been reviewing different methods authorization/authentication in framework. trying assign value state, use ui-routers ability detect state change using $statechangestart. injecting ionicmodal service app.js .run function , creating modal , attaching $rootscope. when try , open following error:

cannot read property 'show' of undefined 

here app.js:

angular.module('authlyapp', ['ionic', 'authlyapp.controllers', 'authlyapp.services'])  .run(function($ionicplatform, $ionicmodal, $rootscope) {   $ionicplatform.ready(function() {     if (window.cordova && window.cordova.plugins.keyboard) {       cordova.plugins.keyboard.hidekeyboardaccessorybar(true);       cordova.plugins.keyboard.disablescroll(true);      }     if (window.statusbar) {       statusbar.styledefault();     }   });    $ionicmodal.fromtemplateurl('templates/login.html', {     scope: $rootscope   }).then(function(modal) {     $rootscope.modal = modal;   });    $rootscope.$on('$statechangestart',   function(event, next, tostate, fromstate, toparams, fromparams){     console.log(next)     if ('data' in next && 'requireauth' in next.data) {       event.preventdefault();       $rootscope.modal.show();     }   });  })  .config(function($stateprovider, $urlrouterprovider) {   $stateprovider    .state('app', {     url: '/app',     abstract: true,     templateurl: 'templates/menu.html',     controller: 'appctrl',     data: {       requireauth: true     }   })    .state('app.search', {     url: '/search',     views: {       'menucontent': {         templateurl: 'templates/search.html'       }     }   })    .state('app.browse', {     url: '/browse',     views: {       'menucontent': {         templateurl: 'templates/browse.html'       }     }   })    .state('app.playlists', {     url: '/playlists',     views: {       'menucontent': {         templateurl: 'templates/playlists.html',         controller: 'playlistsctrl'       }     }   })    .state('app.single', {     url: '/playlists/:playlistid',     views: {       'menucontent': {         templateurl: 'templates/playlist.html',         controller: 'playlistctrl'       }     }   });    $urlrouterprovider.otherwise('/app/playlists'); });