How to programmatically launch into another viewController if your user is logged in through Facebook

Question

Basically I have one class called facebookLogin.swift, the login page, and ViewController.Swift the homepage. I have correctly coded all the Facebook login stuff and it all

Answer 1

Swift 3 code

// Check Last AccesToken

    if let accessToken = AccessToken.current {
        print("Last AccesToken -\(accessToken)")

        // Redirect to next screen
        self.performSegue(withIdentifier:"NextScreen", sender: self)
    }
    else {

        let loginManager = LoginManager()
        loginManager.loginBehavior = LoginBehavior.web
        loginManager.logIn([ .publicProfile , .email, .userFriends], viewController: self) { loginResult in
            switch loginResult {

            case .failed(let error):
                print(error)
                break
            case .cancelled:
                print("User cancelled login.")
                break
            case .success(let grantedPermissions, let declinedPermissions, let accessToken):
                print("Logged in! \(grantedPermissions) \(accessToken) \(declinedPermissions)")

                // Save Current UserInfo
                let params = ["fields":"id,name,email,picture"]
                let graphRequest = GraphRequest(graphPath: "me", parameters: params)
                graphRequest.start { (urlResponse, requestResult) in
                    switch requestResult {
                    case .failed(let error):
                        print(error)
                    case .success(let graphResponse):
                        if let responseDictionary = graphResponse.dictionaryValue {

                            print("\(String(describing: graphResponse.dictionaryValue))")

                            UserDefaults.standard.set(responseDictionary, forKey: "userInfo")
                        }
                    }
                }

                self.performSegue(withIdentifier: "NextScreen", sender: self)
                break
            }
        }
    }

Answer 2

Your code seems ok. You should consider checking Storyboard ID of your ViewController under Identity section in Storyboard design screen. You should give Storyboard ID as "ViewController". Login screen's Storyboard ID should be "facebookLogin" according to your code.