ios - Firebase-Swift : How to add every created user to a friends list when created?

Question

我正在尝试创建一个社交媒体应用程序，并在此过程中尝试在我的数据库中创建一个 friend 列表。我对数据库的结构有大致的了解，但在实际代码中需要帮助，因为我对 Swift 开发还很陌生。

这是我当前的数据库结构:

users

uid_0

name: "John"

email: "john@gmail.com"

uid_1

name: "Doe"

email: "doe@gmail.com"

uid_2

name: "User"

email: "user@gmail.com"

这是我的注册 View Controller 代码

import Foundation
import Firebase
import SwiftKeychainWrapper

class SignUpVC: UIViewController {

    @IBOutlet weak var emailField: UITextField!
    @IBOutlet weak var usernameField: UITextField!
    @IBOutlet weak var passField: UITextField!
    @IBOutlet weak var cPassField: UITextField!
    @IBOutlet weak var SignUpButton: UIButton!

    var userUid: String!
    var email: String!
    var username: String!
    var password: String!
    var cPassword: String!
    var friends: [String] = []

    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.addGestureRecognizer(UITapGestureRecognizer(target: self.view, action: #selector(UIView.endEditing(_:))))
        // Do any additional setup after loading the view.
    }
    override func viewDidDisappear(_ animated: Bool) {

        if let _ = KeychainWrapper.standard.string(forKey: "uid") {

            performSegue(withIdentifier: "toLogin", sender: nil)
        }
    }

    func printAlert(Header: String, Message: String) {
        let alert = UIAlertController(title: Header, message: Message, preferredStyle: .alert)

        alert.addAction(UIAlertAction(title: "Ok", style: .default, handler: nil))

        self.present(alert, animated: true)
    }

    @IBAction func createAccount (_ sender: AnyObject) {

        if password != cPassword {
            self.printAlert(Header: "Error", Message: "Passwords Do Not Match")
        }
        else{
            guard let email = emailField.text, let password = passField.text, let username = usernameField.text else {
                print("Form is not valid")
                return
            }

            Auth.auth().createUser(withEmail: email, password: password, completion: { (res, error) in

                if let error = error {
                    print(error)
                    if let error = AuthErrorCode(rawValue: error._code) {

                    switch error {
                        case .invalidEmail:
                            self.printAlert(Header: "Error", Message: "invalid email")
                        case .emailAlreadyInUse:
                            self.printAlert(Header: "Error", Message: "in use")
                        default:
                            self.printAlert(Header: "Error", Message: "Create User Error")
                    }
                }
                    return
                }

                guard let uid = res?.user.uid else {
                    return
                }

                //successfully authenticated user
                let ref = Database.database().reference(fromURL: "https://messagingdemo-af075.firebaseio.com/")
                let usersReference = ref.child("users").child(uid)
                let values = ["username": username, "email": email, "password": password]
                usersReference.child("friends").setValue(self.friends)
                usersReference.updateChildValues(values, withCompletionBlock: { (err, ref) in

                    if let err = err {
                        print(err)
                        return
                    }

                    self.performSegue(withIdentifier: "toHome", sender: nil)

                })

            })
        }
    }
}

我正在尝试实现如下所示的数据库结构:

users

uid_1

name: "John"

email: "john@gmail.com"

friends

uid_2: = true

uid_3: = false

uid_2

name: "Doe"

email: "doe@gmail.com"

uid_3

name: "User"

email: "user@gmail.com"

我假设当新用户注册时，我必须将每个创建的用户 ID 添加到每个用户的好友列表中。但是，我不知道如何以编程方式快速编写该代码，希望得到一些帮助。

Answer 1

您应该通过在 View Controller 中编写的代码段来使用代表用户的模型类。

例如(查看 Swift Structures and Classes 文档):

class User {
    var uID: String!
    var email: String!
    var name: String!
    var password: String!
    var friends: [String] = []
}

然后在 View Controller 中初始化User列表。

var users: [User]

因此，User 模型(在您的数据库中)看起来几乎相同，除了属性 friends 之外。由于它的类型为 [String] (字符串列表)，因此它应该如下所示:

我们假设 John 有 friend “user2”、“user4”和“user9”。

uID : "uID_1"
email : "john@mail.com"
name : "John"
password : "..."
friends : ["uID_2", "uID_4", "uID_9"]

---

我不会详细介绍，但是:
您还可以采用另一种方式，将好友列表与用户分开。

"uID_1" : ["uID_2", "uID_4", "uID_9"]
"uID_2" : ["uID_1", "uID_6"]
...

...只是说有很多方法可以做到...