Swift Firebase - 有没有办法直接设置 Auth.auth().currentUser && Auth.auth().currentUser?.uid

Question

主要问题是可以从保存的Auth 对象中设置一个零Auth 对象：

let oldAuth = Auth.auth().currentUser
let oldAuthId = Auth.auth().currentUser?.uid

let newAuth = Auth.auth().currentUser
let newAuthId = Auth.auth().currentUser?.uid

newAuth?.delete { (error) in
    if let error = error { return }

    // *** Auth is now nil ***

    // set the nil Auth to the oldAuth
    Auth.auth().currentUser = self.oldAuth
    Auth.auth().currentUser?.uid = self.oldAuthId
}

上面的代码不起作用，我想让它工作，但问题是你为什么要做这样的事情。解释如下。

我在使用匿名登录并创建帐户登录时遇到了问题。

userA 首先匿名登录，他们会得到一个User? 值（Auth.auth().currentUser）和 userId 值（Auth.auth().currentUser?.uid）：

var anonymousUser: User? // "object123"
var anonymousUserId: String? // "id456"

Auth.auth().signInAnonymously(completion: { [weak self](authDataResult: AuthDataResult?, error) in

        if let error = error { return }

        guard let _ = authDataResult?.user.uid else { return }

        self?.anonymousUser = authDataResult?.user // "object123"
        self?.anonymousUserId = authDataResult?.user.uid // "id456"
    })
}

稍后用户创建一个帐户并获得一个全新的User? 值（Auth.auth().currentUser）和 userId 值（Auth.auth().currentUser?.uid）。他们创建帐户后，更新参考时出现问题。他们决定取消并宁愿保持匿名用户，而不是继续。

var realUser: User? // "objectABC"
var realUserId: String // "idXYZ"

Auth.auth().createUser(withEmail: emailTextField.text!, password: passwordTextField.text!, completion: { [weak self] (authDataResult: AuthDataResult?, error) in

        if let error = error { return }

        guard let realUserId = authDataResult?.user.uid else { return }

        self?.realUser = authDataResult?.user // "objectABC"
        self?.realUserId = authDataResult?.user.uid // "idXYZ"

        let someRef = Database.database().reference().child("some").child(realUserId).childByAutoId()
        someRef?.updateChildValues(someDict, withCompletionBlock: { [weak self] (error, ref) in

        if let error = error {

             self?.problemAlert()

            // *** PROBLEM *** present alert giving the user the option to cancel or continue on as an anonymous user
            return 
        }
    })
})

我现在的做法是，如果用户决定取消我从 FB 中删除用户对象：

func problemAlert() {

    let alert = UIAlertController ...

    let tryAgainAction = UIAlertAction...

    let cancelAction = UIAlertAction(title: "Cancel", style: .default) { (action) in

        // *** COMPLETELY DELETE THE USER ***
        let user = self.realUser
        user?.delete { (error) in
            if let error = error { return }

            // *** Auth is now nil ***

            // *** set Auth back to the anonymousUser values but this doesn't work ***
            Auth.auth().currentUser = self.anonymousUser
            Auth.auth().currentUser?.uid = self.anonymousUserId
        }
    }
}

这里的问题是匿名用户登录对象现在已替换为真实用户对象，因为创建了新帐户。但是因为我删除了User?在警报的取消操作中，userA 现在为零。

有没有办法可以设置 nil Auth 对象做这样的事情：

// this doesn't work
Auth.auth().currentUser = anonymousUser
Auth.auth().currentUser?.uid = anonymousUserId

解决方法可以简单地是不要删除新创建的当前用户，让 userA 作为他们继续，但这不是我想要做的。

Answer 1

通常的方法是允许用户在不登录的情况下创建他们已识别的帐户（使用社交服务提供商或电子邮件+密码），然后link the new account with their existing anonymous account。

因此，对于电子邮件+密码，您无需调用createUser(withEmail: , password:)，而是使用

创建他们的凭据

let credential = EmailAuthProvider.credential(withEmail: email, password: password)

然后将它们链接到：

user.link(with: credential) { (authResult, error) in
  // ...
}