Reload UITabbarController along with it's child view controller when log out

Could you perform a segue to the same view controller (there are ways) and set things up in viewWillAppear?

you could use the NSNotification center. simply subscribe all your viewControllers in your tabBar to a notification and set it up so that they set their data sources to nil whenever a user logs out. then when the log out button is pressed, publish that notification.

so in each view controller in viewDidLoad subscribe to the notification:

[[NSNotificationCenter defaultCenter] addObserver:self
        selector:@selector(logoutOccurred:) 
        name:@"Logout"
        object:nil];

and then add a method called logoutOccurred that sets the data source to nil:

- (void)logoutOccurred {

self.messages = nil;
}

When the logout button is pressed, you need to publish the logout notification:

//inside your logout button IBaction
[[NSNotificationCenter defaultCenter] 
        postNotificationName:@"Logout" 
        object:self];

all your subscribing objects will be notified, and they will run whatever code you have specified in your selector when you first subscribed.

You need to be sure and unsubscribe your notifications. implement the dealloc method in each of your view controllers and add:

- (void) dealloc
{

 [super dealloc];
    [[NSNotificationCenter defaultCenter] removeObserver:self];

}

the prevents the center from sending messages to deallocated objects