How to log out from google account in ios? - ios

Question

In my app i have a option to login to the app using google sign in. Login is working fine. Once i click the Logout Button, I am not able to logout from google. When ever I click on login button it's not showing login page as image given below:
Instead its redirecting to authentication dialog page as image given below:
Code :
override func viewDidLoad()
{
super.viewDidLoad()
GIDSignIn.sharedInstance().uiDelegate = self
let button = GIDSignInButton(frame: CGRectMake(0, 0, 100, 100))
button.center = view.center
view.addSubview(button)
}
#IBAction func signOutButton(sender: AnyObject) {
GIDSignIn.sharedInstance().signOut()
}

Answer 1

1.import below
import GoogleAPIClient
import GTMOAuth2
2.declare below variable
let kKeychainItemName = "your app name"
let kClientID = "your app clinet id"
let scopes = [kGTLAuthScopeDrive]
let service = GTLServiceDrive()
3.replace this methods to your existing one
override func viewDidLoad() {
super.viewDidLoad()
if let auth = GTMOAuth2ViewControllerTouch.authForGoogleFromKeychainForName(
kKeychainItemName,
clientID: kClientID,
clientSecret: nil) {
service.authorizer = auth
}
self.tblView.tableFooterView=UIView()
// Do any additional setup after loading the view.
}
override func viewDidAppear(animated: Bool) {
if let authorizer = service.authorizer,
canAuth = authorizer.canAuthorize where canAuth {
fetchFiles()
} else {
presentViewController(
createAuthController(),
animated: true,
completion: nil
)
}
}
func fetchFiles() {
let query = GTLQueryDrive.queryForFilesList()
query.pageSize = 10
query.fields = "nextPageToken, files(id, name)"
service.executeQuery(
query,
delegate: self,
didFinishSelector: #selector(GoogleDriveVC.displayResultWithTicket(_:finishedWithObject:error:))
)
}
// Parse results and display
func displayResultWithTicket(ticket : GTLServiceTicket,
finishedWithObject response : GTLDriveFileList,
error : NSError?) {
if let error = error {
showAlert("Error", message: error.localizedDescription)
return
}
if let files = response.files where !files.isEmpty {
for file in files as! [GTLDriveFile] {
self.arrayOfNames.append(file.name)
self.arrayOfIdentifier.append(file.identifier)
}
}
self.tblView.reloadData()
}
// Creates the auth controller for authorizing access to Drive API
private func createAuthController() -> GTMOAuth2ViewControllerTouch {
let scopeString = scopes.joinWithSeparator(" ")
return GTMOAuth2ViewControllerTouch(
scope: scopeString,
clientID: kClientID,
clientSecret: nil,
keychainItemName: kKeychainItemName,
delegate: self,
finishedSelector: #selector(GoogleDriveVC.viewController(_:finishedWithAuth:error:))
)
}
// Handle completion of the authorization process, and update the Drive API
// with the new credentials.
func viewController(vc : UIViewController,
finishedWithAuth authResult : GTMOAuth2Authentication, error : NSError?) {
if let error = error {
service.authorizer = nil
showAlert("Authentication Error", message: error.localizedDescription)
return
}
service.authorizer = authResult
dismissViewControllerAnimated(true, completion: nil)
}
// Helper for showing an alert
func showAlert(title : String, message: String) {
let alert = UIAlertController(
title: title,
message: message,
preferredStyle: UIAlertControllerStyle.Alert
)
let ok = UIAlertAction(
title: "OK",
style: UIAlertActionStyle.Default,
handler: nil
)
alert.addAction(ok)
presentViewController(alert, animated: true, completion: nil)
}
at last logout using
func logout(){
//logout code
GTMOAuth2ViewControllerTouch.removeAuthFromKeychainForName(kKeychainItemName)
navigationController?.popViewControllerAnimated(true)
}
this is the full implementation

Answer 2

If OP is still looking (doubt it since it's been 3 years) and if anyone is still working on this I think I figured it out.
I'm using Objective C but the methodology is still the same.
I have an app that uses Google Sign In to authenticate. This work as OP has described. For our sign out I have the following:
(IBAction)didTapSignOut:(id)sender
{
GIDSignIn *gidObject = [GIDSignIn sharedInstance];
[gidObject signOut];
[gidObject disconnect];
NSString *logOutUrl = #"https://www.google.com/accounts/Logout";
[[UIApplication sharedApplication] openURL:[NSURL URLWithString: logOutUrl] options:#{} completionHandler:nil];
}
Make sure signOut is before disconnect (i originally had those two reversed and it did not sign the user out).
For our workflow I have it so that the logout url appears. This works because if the user wants to sign in again then they need to authenticate. If the user is signed in already it bypasses the authentication and goes directly into application.