Trying to change button text in a view from an appDelegate method - objective-c

Question

I'm a little new to iOS development and am running into a little problem.
I've implemented the FB SDK for iOS login into my app, and I can login and out no problem.
However, what I'm trying to do is change the single button text from 'Log in' to 'Log out', depending on the state of the FB session.
In my appDelegate (which handles the FB session state changes), I'm calling two methods from my main view controller like this:
helloappViewController * vc = [[helloappViewController alloc]init];
[vc showLogInButton];
...and...
helloappViewController * vc = [[helloappViewController alloc]init];
[vc showLogOutButton];
The methods in helloappViewController that are being called are these:
- (void) showLogInButton {
NSLog(#"Changing button text to 'Login'.");
[self.buttonLogInLogOut setTitle:#"Login" forState:UIControlStateNormal];
}
- (void) showLogOutButton {
NSLog(#"Changing button text to 'Logout'.");
[self.buttonLogInLogOut setTitle:#"Logout" forState:UIControlStateNormal];
}
I know these methods is being called properly because I can see the console log output fine, and I know I'm logged in and out via FB because of other console log outputs I've set.
However, the button title text is not being changed.
Anyone have any idea where I might be going wrong?
Thx.

Answer 1

Try to move code
[self showLogInButton];
and
[self showLogOutButton];
to viewDidLoad method of the helloappViewController view controller
something like this:
helloappViewController * vc = [[helloappViewController alloc]init];
vc.fbIsConnected = YES;
in viewDidLoad:
if (self.fbIsConnect)
{
[self showLogOutButton];
}
else
{
[self showLogInButton];
}
In vc:
[[NSNotificationCenter defaultCenter] addObserver: self
selector: #selector(fbDidChange)
name: FBDidChangeNotification
object: nil];
- (void) fbDidChange
{
// change button title
}
in fb controller:
[[NSNotificationCenter defaultCenter] postNotificationName:FBDidChangeNotification object:self];