Swift - Getting error from facebook login

问题:

just to start off with I have looked at many examples but can't seem to find a solution. Well I thought I did but it doesn't seem to work.

What I'm trying to do is use the Firebase auth login method for facebook, which works by the way. My issue is I want to link the password auth credentials and facebook auth credentials when the facebook method throws the error that the email/credentials already exist. I read here that I could use error.email but it doesn't give me the option to access the email.error. I might be missing something and I have spent a lot of time trying to figure it out.

Here is my code:

func signInFacebookUser() {
    let fbLoginManager = FBSDKLoginManager()
    fbLoginManager.logIn(withReadPermissions: ["public_profile", "email"], from: self) { (result, error) in
        if let error = error {
            self.errorMessagePopUp(title: "Failed to login", message: error)
            return
        }

        guard let accessToken = FBSDKAccessToken.current() else {
        print("Failed to get access token")
        return
   }

   let credential = FacebookAuthProvider.credential(withAccessToken: accessToken.tokenString)

   Auth.auth().signIn(with: credential, completion: { (user, error) in
        if let error = error {

        let errCode = AuthErrorCode(rawValue: error._code)!

        switch errCode {

              case .accountExistsWithDifferentCredential:
              // somehow obtain email right here.
              self.showSigninForm(attributes: self.attributes(), style: .light)
              return

             default:
             return
          }
       }

       self.performSegue(withIdentifier: "signInBtnPressed", sender: nil)
    })
  }
}

回答1:

Try this code

@IBAction func facebookLoginButtonTapped(_ sender: UIButton) {
        if Utility.checkInternet(){
            let fbLoginManager: FBSDKLoginManager = FBSDKLoginManager()
            fbLoginManager.logIn(withReadPermissions: ["email", "public_profile"], from: self) { (result, error) in
                if (error == nil){
                    let fbLoginResult: FBSDKLoginManagerLoginResult = result!
                    if fbLoginResult.grantedPermissions != nil {
                        if(fbLoginResult.grantedPermissions.contains("email")){
                            self.facebookLogin()
                        }
                    }
                }
            }
        }
        else{
            Utility.showAlert("Connection Error!", message: "Please check internet connection and retry.", viewController: (self.window?.rootViewController)!)
        }
    }

---

func facebookLogin() {
        Utility.showProgress("")
        if((FBSDKAccessToken.current()) != nil) {

            FBSDKGraphRequest(graphPath: "me", parameters: ["fields":"id, name, first_name, last_name, picture.type(large), email "]).start(completionHandler: { (connection, result, error) in
                if result == nil {
                }
                else{
                    self.userResults = result as! [String : AnyObject]
                    self.email = (self.userResults["email"] as? String) ?? ""
                    if (self.email != "") {

                    }
                    else{
                        Utility.showAlert("Login Faild", message: error?.localizedDescription, viewController: self)
                    }
                }
            })
        }
    }

回答2:

This Works for me Swift4

@objc func loginButtonClicked() {
    var alertController = UIAlertController()
    let loginManager = LoginManager()
    loginManager.logIn(readPermissions: [ReadPermission.email], >viewController: self, completion: {loginResult in
                    switch loginResult {
                    case .failed(let error):
                        print(error)
                    case .cancelled:
                        print("User cancelled login.")
                    case .success(_, _, let accessToken):
                        print(accessToken)

                    }

    })
}

 func getDataUser() {
        let request = GraphRequest(graphPath: "me?fields=first_name,last_name,email",
                                   parameters:[:],
                                   httpMethod: .GET)
        request.start { httpResponse, result in
            switch result {
            case .success(let response): do {
                print("Graph Request Succeeded: \(response)")
                let dicval = response.dictionaryValue
                let email = dicval?.keys
                print("Graph Request Succeeded: \(String(describing: email))")
                }
            case .failed(let error):
                print("Graph Request Failed: \(error)")
            }

        }
    }
}