SSO requiring multiple attempts to login

Question

When the user tries to login into my iOS app using Facebook Connect's Single Sign-On (SSO), it fails multiple times before letting the user login to the app. This does not occur every time, but occurs the first time the user tries to login using Facebook.

Steps to Reproduce:

1. User should have the latest version of the Facebook iOS app installed on their iPhone.
2. In multitasking, ensure that the Facebook app and your base app are both closed.
3. Tap on Connect with Facebook button in your base app.
4. This opens your Facebook app and redirects back to your base app without any action.

Expected Behavior:

• (void)fbDidLogin method should be called which would authenticate within the base app.

Actual Behavior:

• (void)fbDidNotLogin:(BOOL)cancelled is called for the first time alone.

Answer 1

A very good start point would be this link. You can now download the new facebook SDK and can integrate this SDK into your iOS app. The link describs step by step solution. NO need to use login delegate methods like fbdidlogin etc.

You can check weather the user is logged in with the help of sessionStateChanged event.

- (void)sessionStateChanged:(FBSession *)session
                  state:(FBSessionState) state
                  error:(NSError *)error
{
switch (state) {
    case FBSessionStateOpen:
        if (!error) {
            // We have a valid session
            NSLog(@"User session found");
        }
        break;
    case FBSessionStateClosed:
        NSLog(@"session state closed");
        break;
    case FBSessionStateClosedLoginFailed:
        [FBSession.activeSession closeAndClearTokenInformation];
        break;
    default:
        break;
}

[[NSNotificationCenter defaultCenter] postNotificationName:FBSessionStateChangedNotification
                                                    object:session];
 }

in your view controller you can user following condition to check weather the user is logged in :

if (FBSession.activeSession.isOpen) { 
     // your code here
 }

All is described in the link given.