swift - 即使用户名被占用，注册仍然成功

Question

我想创建一个系统，如果用户名已被其他人占用，用户将无法注册。然而，这似乎不起作用，因为即使用户名已被使用，注册过程仍然完成。

我通过从 Firebase 检索每个用户名并运行它来查看用户输入的用户名是否已被使用来执行此操作。如果是，它应该停止注册过程并告诉用户输入另一个用户名。

代码:

let ref = Database.database().reference(fromURL: "https://heytest.firebaseio.com/")
        let usernamesRef = ref.child("users")

        usernamesRef.observeSingleEvent(of: .value, with: { (snapshot) in
            let con = snapshot.value as! [String:[String:Any]]
            var usernamesArray = [String]()
            Array(con.keys).forEach {
                if let res = con[$0] , let username = res["username"] as? String {
                    usernamesArray.append(username)
                }
            }

            for storedUsername in usernamesArray {
                if storedUsername == self.usernameTextField.text! {
                    self.usernameVerified = false
                    self.usernameLabel.textColor = UIColor.red
                    self.usernameLabel.text = "USERNAME TAKEN"
                    self.usernameTextField.layer.addBorder(edge: UIRectEdge.bottom, color: UIColor.red, thickness: 1.5)
                    return
                }
           }


        }) { (error) in
            print(error.localizedDescription)
        }


        print("TEST")
        self.usernameVerified = true
        print(self.usernameVerified)
        self.usernameTextField.layer.addBorder(edge: UIRectEdge.bottom, color: UIColor.black, thickness: 1.5)
        self.usernameLabel.textColor = UIColor.black
        self.usernameLabel.text = "USERNAME"

点击登录按钮时:

@IBAction func onSignUp(_ sender: Any) {

    print("Sign Up pressed")
    isValidUsername(username: usernameTextField.text!)
    print("[SIGN UP] - Username: \(usernameVerified)")
    isValidEmail(email: emailTextField.text!)
    print("[SIGN UP] - Email: \(emailVerified)")
    isValidPassword(password: passwordTextField.text!)
    print("[SIGN UP] - Password: \(passwordVerified)")



    if passwordVerified && emailVerified && usernameVerified {

        Auth.auth().createUser(withEmail: emailTextField.text!, password: passwordTextField.text!) { (authResult, error) in
            if error != nil {
                self.errorLabel.alpha = 1
                self.errorLabel.text = error?.localizedDescription
                self.shake(viewToShake: self.errorLabel)
                return
            }

            guard let user = authResult?.user else {
                return
            }


            //Successfully Authenticated User
            let ref = Database.database().reference(fromURL: "https://heytest.firebaseio.com/")
            let usersReference = ref.child("users").child(user.uid)
            let values = ["username": self.usernameTextField.text!, "email": self.emailTextField.text!, "games-played": "0"] 
            usersReference.updateChildValues(values, withCompletionBlock: { (err, ref) in
                if err != nil {
                    print(err!)
                    return
                }

                //Successfully registered user's data to database
                print("[SIGN UP] - Successfully Signed Up")
                self.errorLabel.alpha = 0
                self.present((self.storyboard?.instantiateViewController(withIdentifier: "TabBarViewController"))!, animated: false, completion: nil)


            })
        }

    } else {

        errorLabel.alpha = 1
        shake(viewToShake: errorLabel)
        print("Password/Email/Username verification not complete!")
        print("[SIGN UP] - Password: \(passwordVerified)")
        print("[SIGN UP] - Username: \(usernameVerified)")
        print("[SIGN UP] - Email: \(emailVerified)")

    }

}

Answer 1

我认为您可以更轻松地查看 Firebase 是否针对特定用户名抛出任何匹配项。

let reference = Database.database().reference()
reference.child("users").queryOrdered(byChild: "username").queryEqual(toValue: "yourNewUserName").observeSingleEvent(of: .value) { (snapshot) in
    // if there is data in the snapshot reject the registration else allow it
}

否则您将向客户端下载过多的数据。如果您的用户不断增长，下载也将需要很长时间。