嘗試從另一個控制器訪問變量時獲取一個未定義的變量angularjs

Question

嗨，我是新來的angularjs和任何幫助將不勝感激。我授權用戶提供服務，我的服務看起來像這樣

'use strict'; 
app.factory('Auth', function ($firebaseSimpleLogin, FIREBASE_URL, $rootScope, $firebase) { 
    var ref = new Firebase(FIREBASE_URL); 
    var auth = $firebaseSimpleLogin(ref); 
    var Auth = { 
     register: function (user) { 
      return auth.$createUser(user.email, user.password); 
     }, 
     createProfile: function (user) { 
      var profile = { 
       userfirstname: user.fname, 
       userlastname: user.lname, 
       username: user.fname + " " + user.lname, 
       userprofiletags: user.profiletags 
      }; 
      var profileRef = $firebase(ref.child('profile')); 
      return profileRef.$set(user.uid, profile); 
     }, 
     login: function (user) { 
      return auth.$login('password', user); 
     }, 
     logout: function() { 
      auth.$logout(); 
     }, 
     resolveUser: function() { 
      return auth.$getCurrentUser(); 
     }, 
     signedIn: function() { 
      return !!Auth.user.provider; 
     }, 
     user: {} 
    }; 
    $rootScope.$on('$firebaseSimpleLogin:login', function (e, user) { 
     console.log('logged in'); 
     angular.copy(user, Auth.user); 
     Auth.user.profile = $firebase(ref.child('profile').child(Auth.user.uid)).$asObject(); 
     console.log(Auth.user); 
    }); 
    $rootScope.$on('$firebaseSimpleLogin:logout', function() { 
     console.log('logged out'); 
     if (Auth.user && Auth.user.profile) { 
      Auth.user.profile.$destroy(); 
     } 
     angular.copy({}, Auth.user); 
    }); 
    return Auth; 
}); 

我想從控制器訪問userprofiletags變量編碼下面

'use strict'; 
app.controller('PostsCtrl', function ($scope, $http, Post, $location, Auth) { 
    $scope.user = Auth.user; 
    $scope.signedIn = Auth.signedIn; 
    $scope.logout = Auth.logout; 
    $scope.usertags = $scope.user.profile.userprofiletags; 
    console.log($scope.usertags); 
    $scope.loadTags = function (query) { 
     return $http.get('support/tags.json'); 
    }; 
    $scope.onChange = function (cbState) { 
     $scope.message = "The switch is now: " + cbState; 
    }; 
    $scope.posts = Post.all; 
    $scope.post = { 
     title: '', 
     description: '', 
     tags: [], 
     Anonymous: 'false' 
    }; 
    var createdtime = moment().format('MMMM Do YY, h:mm:ss a'); 
    $scope.submitQuestion = function() { 
     $scope.post.createdTime = createdtime; 
     $scope.post.creator = $scope.user.profile.username; 
     $scope.post.creatorUID = $scope.user.uid; 
     Post.create($scope.post).then(function (ref) { 
      $location.path('/posts/' + ref.name()); 
     }); 
    }; 
    $scope.deletePost = function (post) { 
     Post.delete(post); 
    }; 
}); 

當我試圖從訪問變量使用{{user.profile.userprofiletags}}查看它給我的價值觀。但是我試圖在我的PostsCtrl中將變量賦值給$ scope.usertags時，結果變得不確定。

如果我不夠清楚，我會道歉。請幫助我解決這個錯誤。非常感謝您的幫助。

Answer 1

由於Firebase調用是異步的，因此在此時未定義Auth.user。你可以做這樣的事情在你的控制器：

Auth.resolveUser().then(function(user) { 
    $scope.usertags = user.profile.userprofiletags; 
}); 

Answer 2

我覺得這裏的問題是執行console.log撥打電話所以基本上$scope.user.profile.userprofiletags不會在這個時間點之後存在很短，實際上它此事件被廣播'$firebaseSimpleLogin:login'

將準備你可以使用$手錶，並摧毀它接收數據

watchDestroyer = $scope.$watch('user.profile', function (newUserProfile) { 
    if (typeof newUserProfile !== "undefined" && newUserProfile !== null) { 
     $scope.user = newUserProfile 
     watchDestroyer() 
    } 
}) 

後或利用事件或使用承諾