swift - 如何从 Coordinator 类更新 EnvironmentObject 变量？

Question

当用户通过 FB 登录按钮完成授权时，我正在使用 Coordinator(符合 LoginButtonDelegate)对象来接收用户数据(配置文件、姓名)。
Coordinator().userId 属性使用用户 ID 进行更新，但我需要将其向上传递 1 级到 LoginView 并更新名为 thisSession 的 EnvironmentObject(以某种方式使 thisSession.userId = Coordinator().userId)。

有没有办法做到这一点？我尝试使用 ObservableObject/Published 属性，但我无法从 Coordinator 更新父对象的属性。

另一个想法是订阅 Auth.auth() 更改，但这似乎太复杂了，有点“老派”的解决方案。有一些我想念的简单方法。

任何提示/想法？

import SwiftUI
import FirebaseCore
import FirebaseAuth
import FBSDKLoginKit
import FBSDKCoreKit

struct LoginView: View {
    @EnvironmentObject var thisSession: CurrentSession
    @ObservedObject var mainData = MainViewModel()

    var facebookView = facebook()

    var body: some View {
        VStack {
            facebookView.frame(width: 240, height: 50)
            Text("\(self.thisSession.userId ?? "none")")
        }
    }
}

struct LoginView_Previews: PreviewProvider {
    static var previews: some View {
        LoginView().environmentObject(CurrentSession())
    }
}


struct facebook: UIViewRepresentable {
    @EnvironmentObject var thisSession: CurrentSession
    @ObservedObject var coordinator = Coordinator()

    func makeCoordinator() -> facebook.Coordinator {
        return self.coordinator
        //facebook.Coordinator()
    }

    func makeUIView(context: UIViewRepresentableContext<facebook>) -> FBLoginButton {

        let button = FBLoginButton()
        button.delegate = self.coordinator
        print("UPDATED")

        return button
    }

    func updateUIView(_ uiView: FBLoginButton, context: UIViewRepresentableContext<facebook>) {
    }

    class Coordinator: NSObject, LoginButtonDelegate, ObservableObject {
        @Published var userId: String?
        func loginButton(_ loginButton: FBLoginButton, didCompleteWith result: LoginManagerLoginResult?, error: Error?) {

            if error != nil{

                print((error?.localizedDescription)!)
                return
            }
            if AccessToken.current != nil{

                let credential = FacebookAuthProvider.credential(withAccessToken: AccessToken.current!.tokenString)

                Auth.auth().signIn(with: credential) { (res,er) in

                    if er != nil{
                        print((er?.localizedDescription)!)
                        return

                    }
                    print("email: \(String(describing: res?.user.email))")
                    print("name: \(String(describing: res?.user.displayName))")
                    self.userId = String(describing: res?.user.displayName)
                }
            }
        }

        func loginButtonDidLogOut(_ loginButton: FBLoginButton) {
            print("logged out")
            try! Auth.auth().signOut()

        }
    }

}

Answer 1

尝试以下操作，因为在更新期间创建了协调器，环境对象应该已经被注入(inject)并存在，所以它应该可以工作

struct facebook: UIViewRepresentable {
    @EnvironmentObject var thisSession: CurrentSession

    func makeCoordinator() -> facebook.Coordinator {
        Coordinator(session: thisSession)              // << here !!
    }

    func makeUIView(context: UIViewRepresentableContext<facebook>) -> FBLoginButton {

        let button = FBLoginButton()
        button.delegate = self.coordinator
        print("UPDATED")

        return button
    }

    func updateUIView(_ uiView: FBLoginButton, context: UIViewRepresentableContext<facebook>) {
    }

    class Coordinator: NSObject, LoginButtonDelegate, ObservableObject {
        let session: CurrentSession
        init(session: CurrentSession) {
            self.session = session
        }

        func loginButton(_ loginButton: FBLoginButton, didCompleteWith result: LoginManagerLoginResult?, error: Error?) {

            if error != nil{

                print((error?.localizedDescription)!)
                return
            }
            if AccessToken.current != nil{

                let credential = FacebookAuthProvider.credential(withAccessToken: AccessToken.current!.tokenString)

                Auth.auth().signIn(with: credential) { (res,er) in

                    if er != nil{
                        print((er?.localizedDescription)!)
                        return

                    }
                    print("email: \(String(describing: res?.user.email))")
                    print("name: \(String(describing: res?.user.displayName))")

                    DispatchQueue.main.async {   // << here 
                        self.session.userId = String(describing: res?.user.displayName)
                    }
                }
            }
        }

        func loginButtonDidLogOut(_ loginButton: FBLoginButton) {
            print("logged out")
            try! Auth.auth().signOut()

        }
    }

}