AngularJS - 如果用户已登录,则显示/隐藏导航项

Question

我有一个单页的AngularJS应用程序,通过Mongoose使用Express,node.js和MongoDB.使用Passport进行用户管理/身份验证.

我希望根据用户是否登录来更改导航栏项.我无法弄清楚如何实现它.

我发现用户是否通过http请求登录:

server.js

app.get('/checklogin',function(req,res){
  if (req.user)
    res.send(true);
  else
    res.send(false);

在前端,我NavController使用Angular的$http服务调用它:

NavController.js

angular.module('NavCtrl',[]).controller('NavController',function($scope,$http) {

    $scope.loggedIn = false;

    $scope.isLoggedIn = function() {

      $http.get('/checklogin')
        .success(function(data) {
          console.log(data);
          if (data === true)
            $scope.loggedIn = true;
          else
            $scope.loggedIn = false;
        })
        .error(function(data) {
          console.log('error: ' + data);
        });
    };
};

在我的导航中,我正在使用ng-show并ng-hide确定哪些选项应该可见.我也在isLoggedIn()用户点击导航项时触发该功能,检查用户是否在每次点击期间登录.

的index.html

<nav class="navbar navbar-inverse" role="navigation">
  <div class="navbar-header">
    <a class="navbar-brand" href="/">Home</a>
  </div>
  <ul class="nav navbar-nav">
    <li ng-hide="loggedIn" ng-click="isLoggedIn()">
      <a href="/login">Login</a>
    </li>
    <li ng-hide="loggedIn" ng-click="isLoggedIn()">
      <a href="/signup">Sign up</a>
    </li>
    <li ng-show="loggedIn" ng-click="logOut(); isLoggedIn()">
      <a href="#">Log out</a>
    </li>
  </ul>
</nav>

问题

我的应用程序中还有其他位置,用户可以在NavController范围之外登录/注销.例如,登录页面上有一个登录按钮,对应于LoginController.我想在我的整个应用程序中实现这一点有更好的方法.

我怎样才能"手表"是否req.user是true在后端,并有我的导航项目作出相应的反应？

Answer 1

您可以使用$rootScope在整个应用程序中共享信息:

.controller('NavController',function($scope,$http, $rootScope) {

    $scope.isLoggedIn = function() {

      $http.get('/checklogin')
        .success(function(data) {
          console.log(data);
          $rootScope.loggedIn = data;
        })
        .error(function(data) {
          console.log('error: ' + data);
        });
    };
};

现在,您可以loggedIn通过访问$rootScope.loggedIn上述代码中的相同方式来更改应用中其他位置的值.

话虽如此,您应该将相关代码抽象为服务和指令.这将允许您有一个中心位置来处理,登录,注销和状态$rootScope.loggedIn.如果您发布其余的相关代码,我可以帮助您找到更具体的答案

Answer 2

您可以在用户成功登录时广播该事件.如果用户登录,则无需继续轮询您的服务器,您可以在内存中保留一个变量,告知您是否有有效会话.您可以使用在服务器端设置的基于令牌的身份验证:

services.factory('UserService', ['$resource',                                        
  function($resource){

    // represents guest user - not logged
    var user = {
        firstName : 'guest',
        lastName : 'user',
        preferredCurrency : "USD",
        shoppingCart : {
            totalItems : 0,
            total : 0
        },                                                  
    };

    var resource = function() {
        return $resource('/myapp/rest/user/:id', 
            { id: "@id"}
    )};

    return {
        getResource: function() { 
            return resource;
        },

        getCurrentUser: function() {
            return user;
        },

        setCurrentUser: function(userObj) {
            user = userObj;
        },

        loadUser: function(id) {
            user = resource.get(id);
        }
    }

  }]);

services.factory('AuthService', ['$resource', '$rootScope', '$http', '$location', 'AuthenticationService', 
  function ($resource, $rootScope, $http, $location, AuthenticationService) {
    var authFactory = {
        authData: undefined       
    };

    authFactory.getAuthData = function () {
        return this.authData;
    };

    authFactory.setAuthData = function (authData) {
        this.authData = {
            authId: authData.authId,
            authToken: authData.authToken,
            authPermission: authData.authPermission
        };
        // broadcast the event to all interested listeners
        $rootScope.$broadcast('authChanged');
    };

    authFactory.isAuthenticated = function () {
        return !angular.isUndefined(this.getAuthData());
    };

    authFactory.login = function (user, functionObj) {
        return AuthenticationService.login(user, functionObj);          
    };

    return authFactory;
}]);

services.factory('AuthenticationService', ['$resource',
  function($resource){
    return $resource('/myapp/rest/auth/', 
            {},
            {
              'login': { method: "POST" }
            }               
    );
  }]);          

services.factory('authHttpRequestInterceptor', ['$injector',  
 function ($injector) {
    var authHttpRequestInterceptor = {
        request: function ($request) {
            var authFactory = $injector.get('AuthService');
            if (authFactory.isAuthenticated()) {
                $request.headers['auth-id'] = authFactory.getAuthData().authId;
                $request.headers['auth-token'] = authFactory.getAuthData().authToken;
            }
            return $request;
        }
    };

    return authHttpRequestInterceptor;
}]);

控制器:

controllers.controller('LoginCtrl', ['$scope', '$rootScope', 'AuthService', 'UserService', 
  function LoginCtrl($scope, $rootScope, AuthService, UserService) {
    $scope.login = function () {
        AuthService.login($scope.userInfo, function (data) {
            AuthService.setAuthData(data);
            // set user info on user service to reflect on all UI components
            UserService.setCurrentUser(data.user);
            $location.path('/home/');               
        });
    };

    $scope.isLoggedIn = function () {
        return AuthService.isAuthenticated();
    }

    $scope.user = UserService.getCurrentUser();         
}])