Navigation Controller-based Login requires 2 attempts

Well your view did load for your root view controller looks good. Try testing your sign up. If sign up works correctly it's probably a problem in your login controller.

Sign up works fine. However, I notice that when sign up returns to root with [self.navigationController popToRootViewControllerAnimated:YES]; (same command as with login) It doesn't call the viewDidLoad IF statement (in the logs), but goes straight to viewWillAppear.

Then again, login also works, its just not registered for some reason on the first attempt when it calls the viewDidLoad.

I've been looking at this for some time and can't see anything that might influence this behavior programmatically. I'll try adding an an activity indicator until the networking has been done and see if that helps.

I do live on the other side of the globe with relatively terrible internet speeds.

Thanks.

I think the issue may be that you are setting the currentUser variable on viewDidLoad when there is nobody logged in yet. Then when you log in and come back, viewDidLoad isn't being called because the view is already loaded and still in memory (we talk about this later in the course).

If you move your code to viewWillAppear it should work okay because viewWillAppear gets called every time the view controller is displayed on the screen, whereas viewDidLoad is not guaranteed to run every time.

Thanks Ben, Moved to viewWillAppear, but behavior remains the same. It takes only one attempt with credentials, but this still goes to login (i can see in the logs the 'else' for [self performSegueWithIdentifier:@"toLogin" sender:self] is processed) , whereby just clicking 'GO' at this point will take me to 'home' tableViewController (with popup error for incomplete fields - but navigates there all the same).

Any idea why (currentUser) would return false at this point to invoke the else, but not on the next click of 'GO'?

sorry, its a bit messy here. Is there a better way to post it so its clean?

I have a workaround. It seems definitely a delay. I used the following in the viewWillAppear

if ([self respondsToSelector:@selector(loginHoldDown)]) {
        [NSTimer  scheduledTimerWithTimeInterval:1 target:self selector:@selector(loginHoldDown) userInfo:nil repeats:NO];

    }

and for the method I moved the if/else to login segue (including the list PFQuery in the 'current user' condition) to after the timeout.

- (void)loginHoldDown {

    PFUser *currentUser = [PFUser currentUser];
    if (currentUser) {
        NSLog(@"Current user: %@", currentUser.username);
        PFQuery *query = [PFQuery queryWithClassName:@"Messages"];
        [query whereKey:@"recipientIds" equalTo:[[PFUser currentUser] objectId]];
        [query orderByDescending:@"createdAt"];
        [query findObjectsInBackgroundWithBlock:^(NSArray *objects, NSError *error) {
            if (error) {
                NSLog(@"Error: %@ %@", error, [error userInfo]);
            }
            else {
                // We found messages!
                self.messages = objects;
                self.allLists = [NSMutableArray arrayWithObjects:self.messages,nil];

                NSLog(@"Retrieved %lu messages", (unsigned long)[self.messages count]);

                [self.tableView reloadData];
            }

        }];

    }
    else {
        [self performSegueWithIdentifier:@"toLogin" sender:self];
    }

}

This holds for 1 second on the 'home' view controller and allows the 'current user' to be identified.

Interestingly if i only set it to 0.5 it doesn't give it enough time and login segue kicks in.