sebsto / amplify-ios-getting-started Goto Github PK

  import UIKit
  import AmplifyPlugins
 import Amplify
  class Backend {

   static let shared = Backend()

   static func initialize() -> Backend {

   return .shared

}

private init() {
  // initialize amplify
  do {
    
    try Amplify.configure()
    try Amplify.add(plugin: AWSCognitoAuthPlugin())
    // in private init() function
    // listen to auth events.
    // see https://github.com/aws-amplify/amplify-ios/blob/master/Amplify/Categories/Auth/Models/AuthEventName.swift
    print("Initialized Amplify");
  } catch {
    print("Could not initialize Amplify: \(error)")
  }
    
    // let's check if user is signedIn or not
    Amplify.Auth.fetchAuthSession { (result) in
         do {
             let session = try result.get()
                    
    // let's update UserData and the UI
         self.updateUserData(withSignInStatus: session.isSignedIn)
                    
         } catch {
              print("Fetch auth session failed with error - \(error)")
        }
    }
    _ = Amplify.Hub.listen(to: .auth) { (payload) in

        switch payload.eventName {

        case HubPayload.EventName.Auth.signedIn:
            print("==HUB== User signed In, update UI")
            self.updateUserData(withSignInStatus: true)

        case HubPayload.EventName.Auth.signedOut:
            print("==HUB== User signed Out, update UI")
            self.updateUserData(withSignInStatus: false)

        case HubPayload.EventName.Auth.sessionExpired:
            print("==HUB== Session expired, show sign in UI")
            self.updateUserData(withSignInStatus: false)

        default:
            //print("==HUB== \(payload)")
            break
        }
    }
}



// MARK: - User Authentication

// signin with Cognito web user interface
public func signIn() {

    _ = Amplify.Auth.signInWithWebUI(presentationAnchor: UIApplication.shared.windows.first!) { result in
        switch result {
        case .success(_):
            print("Sign in succeeded")
        case .failure(let error):
            print("Sign in failed \(error)")
        }
    }
}

// signout
public func signOut() {

    _ = Amplify.Auth.signOut() { (result) in
        switch result {
        case .success:
            print("Successfully signed out")
        case .failure(let error):
            print("Sign out failed with error \(error)")
        }
    }
}

// change our internal state, this triggers an UI update on the main thread
func updateUserData(withSignInStatus status : Bool) {
    DispatchQueue.main.async() {
        let userData : UserData = .shared
        userData.isSignedIn = status   
    }
}