如何检查用户是否具有有效的身份验证会话 Firebase iOS？

Question

在展示我的应用的主视图控制器之前，我想检查用户是否仍有有效会话。我使用最新的 Firebase API。我想如果我使用遗产，我就能知道这一点。

这是我到目前为止所做的：

• 我在 Firebase 的 Slack 社区发布了我的问题，没有人回答。我找到了这个，但这是针对 Android 的：https://groups.google.com/forum/?hl=el#!topic/firebase-talk/4HdhDvVRqHc

• 我尝试阅读 Firebase for iOS 的文档，但似乎无法理解：https://firebase.google.com/docs/reference/ios/firebaseauth/interface_f_i_r_auth

我尝试这样输入 Xcode：

FIRApp().currentUser()
FIRUser().getCurrentUser()

但我似乎找不到那个 getCurrentUser 函数。

Answer 1

if FIRAuth.auth().currentUser != nil {
   presentHome()
} else {
   //User Not logged in
}

对于更新的 SDK

if Auth.auth().currentUser != nil {

}

Answer 2

更新答案

最新 Firebase SDK 的解决方案 - DOCS

    // save a ref to the handler
    private var authListener: AuthStateDidChangeListenerHandle?

    // Check for auth status some where
    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)

        authListener = Auth.auth().addStateDidChangeListener { (auth, user) in

            if let user = user {
                // User is signed in
                // let the user in?

                if user.isEmailVerified {
                    // Optional - check if the user verified their email too
                    // let the user in?
                }
            } else {
                // No user
            }
        }
    }

    // Remove the listener once it's no longer needed
    deinit {
        if let listener = authListener {
            Auth.auth().removeStateDidChangeListener(authListener)
        }
    }

原解决方案

Swift 3 中的解决方案

override func viewDidLoad() {
    super.viewDidLoad()

    FIRAuth.auth()!.addStateDidChangeListener() { auth, user in
        if user != nil {
            self.switchStoryboard()
        }
    }
}

switchStoryboard() 在哪里

func switchStoryboard() {
    let storyboard = UIStoryboard(name: "NameOfStoryboard", bundle: nil)
    let controller = storyboard.instantiateViewController(withIdentifier: "ViewControllerName") as UIViewController

    self.present(controller, animated: true, completion: nil)
}

Source

Answer 3

Swift 4 中的解决方案

override func viewDidLoad() {
    super.viewDidLoad()
    setupLoadingControllerUI()
    checkIfUserIsSignedIn()
}

private func checkIfUserIsSignedIn() {

    Auth.auth().addStateDidChangeListener { (auth, user) in
        if user != nil {
            // user is signed in
            // go to feature controller 
        } else {
             // user is not signed in
             // go to login controller
        }
    }
}

Answer 4

if Auth.auth().currentUser?.uid != nil {

   //user is logged in

    }else{
     //user is not logged in
    }

Answer 5

虽然您可以查看是否有这样的用户使用Auth.auth().currentUser，但这只会告诉您是否有用户通过了身份验证，无论该用户是否帐户仍然存在或有效。

---

完整的解决方案

真正的解决方案应该是使用Firebase的重新认证：

open func reauthenticate(with credential: AuthCredential, completion: UserProfileChangeCallback? = nil)

这确保（在启动应用程序时）先前登录/经过身份验证的用户实际上仍然 已经并且可以通过 Firebase 进行身份验证。

let user = Auth.auth().currentUser    // Get the previously stored current user
var credential: AuthCredential
    
user?.reauthenticate(with: credential) { error in
  if let error = error {
    // An error happened.
  } else {
    // User re-authenticated.
  }
}

Answer 6

override func viewDidLoad() {
FIRAuth.auth()!.addStateDidChangeListener() { auth, user in
            // 2
            if user != nil {
                let vc = self.storyboard?.instantiateViewController(withIdentifier: "Home")
                self.present(vc!, animated: true, completion: nil)
            }
        }
}

来源：https://www.raywenderlich.com/139322/firebase-tutorial-getting-started-2

Answer 7

Objective-c 解决方案是（iOS 11.4）：

[FIRAuth.auth addAuthStateDidChangeListener:^(FIRAuth * _Nonnull auth, FIRUser * _Nullable user) {
    if (user != nil) {
        // your logic
    }
}];