segue

I am wondering about how the functions in the title work and also about the sender parameter. Lets say a button click calls the performSegue method, does that also call the prepareSegue method as well? Is the prepareSegue method called before the performSegue method but after the button is pressed? Also, is the "sender" parameter in both of the functions linked? If I pass in a string as the sender in the performSegue method, will that transfer over to the sender parameter in the prepareSegue method? In other words, if I set the sender parameter in the performSegue method as "Hi world", will

I am designing an iOS app using XCode 4.2's storyboard feature. The app has a login screen that takes a username and password and has a button to log in. Pushing the login button triggers a push seque to another view controller. However, I want the seque to wait until the login comes back successful before proceeding to the next view controller. I know about prepareForSegue:sender: but heres my issue: the login call is asynchronous. I therefore cannot perform the login there. Is there someway around this? Can I create a seque in the storyboard that is only triggered when I want it to be (as

I don't know when I should use Navigation Controller instead of use segue with normal View Controller? And if use segue, which different between Modal and Push segue? Can you give me an example? Short answer: Use a Navigation Controller with "show" segues only to implement DRILL DOWN behavior. For example, Navigation Controller → Authors → Books → Book For each level below the "root" (Authors), the Navigation Controller automatically adds the title bar and back button. So on Books, the back button is automatically named "<Authors". The child View Controllers must be connected with SHOW segues