An UIViewController inside other UIviewController and IBActions - ipad

Question

I'm designing an iPad app where little UIScrollViews have their own UIViewController . Those controllers have in their view a button that call an IBAction method. But it isnt working, in fact, it doesnt seem that they are being pressed in the simulator.
Here is some code to give you an idea of what im am doing .
// In UIViewController A (say the parent or root that have several UIScrollViews)
MiniViewController * mini = [[MiniViewController alloc]init];
[scrollView1 addSubview:mini.view];
//repeat the same process a couple of times with different uiscrollsviews and instances of miniviewcontrollers
Now The MiniController is very simple as you can guess, i only post the .h file
#interface MiniControlador : UIViewController {
IBOutlet UIButton * button;
}
#property (nonatomic, retain) IBOutlet UIButton * button;
- (IBAction)doSomething:(id)sender;
#end
You can see that i used Interface builder to connect an UIButton "button" to a method called doSomething. But as i already said, it isnt working.
One more thing. I also tried to add a button to the UIScrollView with the Mini Controller instance programmatically.And it worked! But I certainly believe that it's extremely hardcoded.
What do you think? I'll appreciate any suggestion(s).

Answer 1

Apple's View Controller Programming Guide is an important read, and explains a lot about Apple's philosophy of one-view-controller-per-screen.
Much of the behavior of view controllers is built on the assumption that there is only one view controller operating at a time. When that assumption is violated, the behavior is undefined (or at least undocumented). In this case, your description suggests that the normal view controller behavior of inserting the controller into the responder chain between its root view and that root's superview (usually the previous screen) isn't working.
While you may find methods of initialization that do work properly, they're not going to be guaranteed to work, and the behavior is liable to change with future OS updates.
Edit: A relevant quotes from the View Controller Programming Guide:
Each custom view controller object you create is responsible for managing all of the views in a single view hierarchy. In iPhone applications, the views in a view hierarchy traditionally cover the entire screen, but in iPad applications they may cover only a portion of the screen. The one-to-one correspondence between a view controller and the views in its view hierarchy is the key design consideration. You should not use multiple custom view controllers to manage different portions of the same view hierarchy. Similarly, you should not use a single custom view controller object to manage multiple screens worth of content.

Answer 2

Thanks guys, I finally solve this using objects of a class (that I called GenericViewController). It actually acts like a regular UIViewController, the IBActions responds well to any event (i.e. buttons being pressed).
I used an IBOutlet UIView in order to contain UILabels, buttons...and so on.
Here is some code if anyone is interested.
#interface GenericViewController : NSObject {
/* Some IBOutlets here*/
//like a regular UIView of an UIViewController, this holds the rest of the outlets
IBOutlet UIView * view;
}
//some IBActions here
}
Then the UIScrollView only add the view of each GenericViewController object
[scrollView addSubview:genericViewControllerObject.view];
If anyone has a better solution, please let me know :)

Answer 3

Are you sure you are loading the view from the xib you made in InterfaceBuilder?
I'm doing something similar in my app, and it's working for me.
I'm implementing the init method like this:
- (id)init
{
if (self = [super initWithNibName:#"__your_xib_name__" bundle:[NSBundle mainBundle]])
{
// TODO: Add additional initializing here
// ...
}
return self;
}
If you are not loading the view from the xib, then there will be no connections made (no IBOutlets initialized and no IBActions triggered).