swift - Firestore 数据库不存储数据

Question

我创建了一个应用程序，当用户注册时，应该在用户文档的 Firestore 服务器中创建两个值，即级别和主题(意味着它在/users/userid 中)。

我已尝试手动创建“用户”集合，但在用户注册时没有创建任何内容。

以下是我的代码(SignUpViewController):

import Firebase

var reference: DocumentReference!

func firebaseAuth() {
    let userDisplayName = textfieldDisplayName.text!
    let userEmail = textfieldEmail.text!
    let userPassword = textfieldPassword.text!

    if userEmail == "" || userPassword == "" {
        labelMessage.isHidden = false
        labelMessage.textColor = UIColor.red
        labelMessage.text = "Error: A compulsory field is left blank."
    } else {
        Auth.auth().createUser(withEmail: userEmail, password: userPassword) { (user, error) in
            if user != nil && error == nil {
                let changeRequest = Auth.auth().currentUser?.createProfileChangeRequest()
                changeRequest?.displayName = userDisplayName
                changeRequest?.commitChanges(completion: { (error) in
                    if error == nil {
                        let userID = Auth.auth().currentUser?.uid
                        let dataToSave: [String: Any] = ["level":0, "subjects":[""]]

                        self.reference = Firestore.firestore().collection("users").document(userID ?? "")
                        self.reference.setData(dataToSave, completion: { (error) in
                            if error == nil {
                                self.performSegue(withIdentifier: "presentInitial", sender: self)
                            } else {
                                self.labelMessage.isHidden = false
                                self.labelMessage.textColor = UIColor.red
                                self.labelMessage.text = "Error: \(error?.localizedDescription ?? "")"
                            }
                        })

                        self.performSegue(withIdentifier: "presentInitial", sender: self)
                    } else {
                        self.labelMessage.isHidden = false
                        self.labelMessage.textColor = UIColor.red
                        self.labelMessage.text = "Error: \(error?.localizedDescription ?? "")"
                    }
                })
            } else {
                self.labelMessage.isHidden = false
                self.labelMessage.textColor = UIColor.red
                self.labelMessage.text = "Error: \(error?.localizedDescription ?? "")"
            }
        }
    }
}

以下代码来自 SignUpViewController 重定向到 (HomeViewController) 的另一个 View Controller:

import Firebase

var reference: DocumentReference!

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
    let userID = Auth.auth().currentUser?.uid
    reference.getDocument { (docSnapshot, error) in // Fatal error occured here
        let data = docSnapshot?.data()
        let userLevel = data?["level"] as? String ?? ""

        if userLevel == "" {
            self.performSegue(withIdentifier: "performSetup", sender: self)
        }
    }
}

我预计当重定向到主页时(通过 presentInitial 进行搜索)，主页将读取“level”的值。但是，该应用程序因 fatal error 而崩溃:“ fatal error :在隐式展开可选值时意外发现 nil”，其中“级别”本应从服务器读取。

Answer 1

我认为问题不在于 Firestore。根据错误信息，代码包装了一个可选值但失败，因为它是nil，所以问题可能出在这三行:

let userDisplayName = textfieldDisplayName.text!
let userEmail = textfieldEmail.text!
let userPassword = textfieldPassword.text!

有时，当 UITextField 没有文本时，它的 text 是 nil 而不是 ""，这可能会导致问题。您可以将这三行替换为以下内容:

let userDisplayName = textfieldDisplayName.text ?? ""
let userEmail = textfieldEmail.text ?? ""
let userPassword = textfieldPassword.text ?? ""

这样，当没有文本时，这三个变量将始终为""，您检查空白字段的逻辑仍然有效。

编辑:为了将来引用，真正的问题不在问题中，而在这个答案的评论中。