Programming a Universal App in iOS

Question

When I am programming a universal app, lets say I have an IBAction like so:

(IBAction)magicCode:(id)sender {

    textField1.text = "TEST";

}

Do I need to create a new IBAction for each view (iPad and iPhone). I can't have textField1 twice in header file, so I am just wondering how everyone else does this. Do I need to put a textfield in the iPhone app with a different name than the one in the iPad app? Or is there some other way everyone else is doing this?

Answer 1

Do I need to create a new IBAction for each view (iPad and iPhone).

First, actions are typically included in view controllers, not views. I think that's probably what you meant, but I point out the difference because I've seen a lot of people get confused on this point.

When you're creating a universal app, i.e. a single app that adapts its UI to the device (iPad or iPhone/iPod Touch) on which it's running, a common strategy is to provide different view layouts that make the best use of the available screen size, but to use the same view controllers. So, for example, say you have an app with a master/detail interface. On small devices, you'd present the master part of the interface first, and when the user chooses something you'd display the detail part of the interface. On an iPad, with it's larger screen, you'd display both master and detail interfaces simultaneously in a split view. Comparing the two, the views are likely to be different, and the way the view controllers are presented is different, but the view controllers themselves should stay the same. This is a good thing, since much of the work of creating an app goes into creating the view controllers.

If your app is similar to what I've described (or if you can make it similar), then no, you don't need separate actions for iPad and iPhone because you'll be using the same view controllers in both cases. There may be times, though, when the behavior of the app on the two different devices is different enough that it makes sense to have iPad-specific and iPhone-specific view controllers. You might still be able to use the same actions by deriving each of those from a common parent class that contains the actions. If not, you'll need to have each class implement its own actions.

Answer 2

No, you can have the same IBAction and IBOutlet in a UIViewController dealing with textfields in two different Nibs (one for iPhone and one for iPad). That's the whole point of separation between View Controller and Views in MVC architecture.

Just use the same UIViewController as File's Owner in both the Nibs and make all the appropriate IBOutlet and IBAction connections and everything will work.