angularjs ui-router生成无限循环

我知道这个问题已被多次讨论过,但解决方案并不符合我的要求.任务很简单.如果用户未登录,则应将用户重定向到登录页面.当我在$on中执行它时,它会产生无限循环.让我知道什么是最好的解决方案.

var adminpanel = angular.module('administrator',['ngmessages','ui.router','ui.bootstrap','ngCookies']);
    adminpanel.config(function ($stateProvider,$urlRouterProvider) {
    //    $urlRouterProvider.otherwise("/login");
        $urlRouterProvider.otherwise( function($injector,$LOCATIOn) {
                var $state = $injector.get("$state");
                $state.go("login");
            });
                $stateProvider
                .state('login',{
                                url: "/login",controller:"userCtrl",templateUrl: "views/login.tpl.html",permissions:{except:['admin']}
                                }
                      )
                  .state('menu',{
                                templateUrl: "views/menu.tpl.html",controller:'adminCtrl',permissions:{allow : ['admin']}
                                }
                      )
                  .state('menu.dashboard',{
                                url: "/dashboard",templateUrl: "views/dashboard.tpl.html",permissions:{allow : ['admin']}
                                }
                      )

});


adminpanel.run([ '$rootScope','$state','$stateParams','$cookieStore',function ($rootScope,$state,$stateParams,$cookieStorE) {
 $rootScope.$state = $state;
    $rootScope.$stateParams = $stateParams;
        $rootScope.$on('$stateChangeStart',function(event,toState,fromStatE){

            if($rootScope.session == undefined && $cookieStore.get('name') == undefined){$rootScope.session={}}
            else if($rootScope.session == undefined && $cookieStore.get('name') != undefined){
                    $rootScope.session={set:true,name : $cookieStore.get('name'),userid :$cookieStore.get('userid'),role:$cookieStore.get('role')};
            };
        //Added below lines as update    
             if(toState.name === "login"){
              return;
            }
        //Added above lines as update
        var authorized = true;
         if(Object.keys($rootScope.session).length === 0){
              event.preventDefault();
            $state.go('login');
         }
        else if(Object.keys(toState.permissions).length !=0){
                    console.log($rootScope.session.rolE);
                    angular.forEach(toState.permissions,function(value,key){
                     angular.forEach(value,function(rolE){
                        if(key === 'except' && role === $rootScope.session.rolE)
                        {authorized = false;}
                        else if(key === 'allow' && role !== $rootScope.session.rolE)
                        {authorized = false;};
                    });
                });
}
if(!authorized){
                        event.preventDefault();
                        $state.go('menu.dashboard');
                };

        });

}]);

在此先感谢您的帮助.

更新1：

解决方案很好.但是,如果用户已登录,则用户在尝试通过地址栏查看时不应访问登录页面.所以我用except键创建了一个权限参数.

但是如果用户通过地址栏点击登录页面,则会生成登录页面,不应该将登录页面重定向到menu.dashboard.

希望我很清楚.

...
// never redirect to state,if already going there
if(toState.name === "login"){
  return;
}

// evaluate some IF here only if we go to other state then login
if(Object.keys($rootScope.session).length === 0) {
  event.preventDefault();
  $state.go('login');
  return;

}