没有显示 Firebase 数据的结果

Question

我是 Javascript 和 Ionic 的初学者，我试着简单地显示数据库中的数据。

但是由于各种设备原因，我在执行此操作时无法检查我的控制台。

无论如何，这是我用来显示用户“描述”的代码：

// Get a database reference to our posts
var descriptionRef = new Firebase("https://swapizapplication.firebaseio.com/accounts/-KOkwpzslw9NyUrTtvA7");
// Attach an asynchronous callback to read the data at our posts reference
descriptionRef.on("value", function(snapshot) {
var descriptionSnapshot = snapshot.child("displayDescription");
var description = descriptionSnapshot.val();
  console.log(snapshot.val());
}, function (errorObject) {
  console.log("The read failed: " + errorObject.code);
});

我想要的是，当我在链接到具有该代码的控制器的 html 页面上编写 {{description}} 时，它会在以下位置显示用户“-KOkwpzslw9NyUrTtvA7”的数据库数据“displayDescription”（该用户数据库中字段之一的名称）

但是它不显示数据。页面出现了，没有特别的错误出现，只是数据没有出现。

这是我制作控制器的方法（全视图）：

.controller('AccountCtrl', function($scope, $state, $cordovaOauth) {
    $scope.$on('$ionicView.enter', function() {
      //Get logged in user credentials.
      var user = firebase.auth().currentUser;
      var name, email, photoUrl, provider;


            console.log("User: " + JSON.stringify(user));
      if (user != null) {
        name = user.displayName;
        email = user.email;
        photoUrl = user.photoURL;
        provider = user.provider;
        description = user.displayDescription

      }

      //Set Profile Image.
      $scope.profileImage = photoUrl;
      //Set Profile Name.
      $scope.profileName = name;
      //Set Profile email.
        profileEmail = email;
            //Set provider.
            provider = provider;

// Get a database reference to our posts
var descriptionRef = new Firebase("https://swapizapplication.firebaseio.com/accounts/-KOkwpzslw9NyUrTtvA7");
// Attach an asynchronous callback to read the data at our posts reference
descriptionRef.on("value", function(snapshot) {
var descriptionSnapshot = snapshot.child("displayDescription");
var description = descriptionSnapshot.val();
  console.log(snapshot.val());
}, function (errorObject) {
  console.log("The read failed: " + errorObject.code);
});
    });
  });

有什么想法可以帮助 NOOB 吗？ :p

编辑：添加我的数据库的 JSON：

{
  "-KOjv0LDdoWrc3uApvPi" : {
    "dateCreated" : "Tue Aug 09 2016 11:29:18 GMT-0400 (EDT)",
    "email" : "bla@blabla.net",
    "provider" : "Facebook",
    "userId" : "FMXlUQZth5aehQLT2TKZZJZdJBh2"
  },
  "-KOkwpzslw9NyUrTtvA7" : {
    "dateCreated" : "Tue Aug 09 2016 16:16:52 GMT-0400 (EDT)",
    "displayDescription" : "no description",
    "email" : "blibli@blibli.com",
    "provider" : "Facebook",
    "userId" : "F9Z7YhSlmAQqOH5FVjBSV2CkYZG3"
  }
}

编辑 2：

我考虑过另一种解决方案，它仍然不想工作！

.controller('AccountCtrl', function($scope, $state, $cordovaOauth) {
    $scope.$on('$ionicView.enter', function() {
    //Get logged in user credentials.
    var user = firebase.auth().currentUser;
    var name, email, photoUrl, provider, description;

    console.log("User: " + JSON.stringify(user));
    if (user != null) {
        name = user.displayName;
        email = user.email;
        photoUrl = user.photoURL;
        provider = user.provider;
    }

    //Set Profile Image.
    $scope.profileImage = photoUrl;
    //Set Profile Name.
    $scope.profileName = name;
    //Set Profile email.
    $scope.profileEmail = email;
    //Set provider.
    $scope.provider = provider;

        var descriptionRef = firebase.database().ref('accounts/' + user + '/displayDescription/' );
        descriptionRef.on('value', function(snapshot) {
        description = snapshot.val();
        $scope.description = description;
        $scope.$apply();
        });
    });

Answer 1

要回答这里的主要问题，您没有在 $scope 中公开“描述”，因此 HTML 模板不知道“描述”存在。因此，通过调用{{description}}，您可能会得到undefined，这就是它不打印任何内容的原因。

然后，指的是火力基地。语句firebase.auth().currentUser 返回firebase.User 或null，具体取决于您是否登录。 firebase.User 不包含 provider 的定义。相反，请尝试使用providerId 或providerData。此外，firebase.User 也不包含displayDescription 的定义。这是您在用户数据中为/accounts/-KOkwpzslw9NyUrTtvA7/displayDescription 定义的任意键。

如果我没记错的话，这应该可以解决问题：

.controller('AccountCtrl', function($scope, $state, $cordovaOauth) {
    $scope.$on('$ionicView.enter', function() {
    //Get logged in user credentials.
    var user = firebase.auth().currentUser;
    var name, email, photoUrl, provider, description;


    console.log("User: " + JSON.stringify(user));
    if (user != null) {
        name = user.displayName;
        email = user.email;
        photoUrl = user.photoURL;
        provider = user.providerId;
    }

    //Set Profile Image.
    $scope.profileImage = photoUrl;
    //Set Profile Name.
    $scope.profileName = name;
    //Set Profile email.
    $scope.profileEmail = email;
    //Set provider.
    $scope.provider = provider;

    // Get a database reference to our posts
    var descriptionRef = new Firebase("https://swapizapplication.firebaseio.com/accounts/-KOkwpzslw9NyUrTtvA7");
    // Attach an asynchronous callback to read the data at our posts reference
    descriptionRef.on("value", function(snapshot) {
        var descriptionSnapshot = snapshot.child("displayDescription");
        description = descriptionSnapshot.val();
        $scope.description = description;
        console.log(snapshot.val());
    }, function (errorObject) {
            console.log("The read failed: " + errorObject.code);
        });
    });
});