iOS possible to access the super class iBoutlets objects in my subclass? - ios

Question

I want to access super class iBoutlets objetcs in my subclass. Is that possible?. I am trying in the following way but am always getting nil.
Here is my code:
My super class
#import <UIKit/UIKit.h>
#interface SuperClassA : UIViewController {
}
#property (weak, nonatomic, getter=getDummyView) IBOutlet UIView *dummyView;
#end
#implementation SuperClassA
- (void)viewDidLoad {
[super viewDidLoad];
SubClassB *obj = [SubClassB new];
[obj printSuperClassiBouletObject];
}
#end
my subclass:
#import <UIKit/UIKit.h>
#interface SubClassB : SuperClassA {
}
#end
#implementation SubClassB
-(void)printSuperClassiBouletObject
{
NSLog(#"view: %#", [self getDummyView]);
}
#end
The above code gives me nil value always. Any idea how to get the actual iBoutlet object?. But when i pass the iBoutlet as an function argument then the object was not nil. In the super class i tried strong property, using #synthesize in implementation file but no helps. Any help that really might be appreciated.

Answer 1

My guess is that the problem is here:
SubClassB *obj = [SubClassB new];
[obj printSuperClassiBouletObject];
New will use default initializer, that will try to load nib with your class name, which is SubClassB. Do you have SubClassB.xib that set the outlet your project? If not, then SubClassB will be initialized with empty properties, by the default objc initializer.
Try this:
SubClassB *obj = [[SubClassB alloc] initWithNibName:#"SuperClassA"]; //or xib name that SuperClassA uses to initialize

Answer 2

There's nothing special about IBOutlet relative to the scope rules. You can inherit any property from super by including its declaration in the subclass. The simple way to do this is by placing those property declarations in the superclass's public interface (in superclass.h). Since we know that the subclass must import that, we know that everything in there will be available to the subclass.
A more complicated arrangement is required if you'd like the subclass to access the property but not other classes. These "protected" declarations need to go into a third header file that only the super and subclass import.
In other words... (simple case):
// MySuper.h
#interface MySuper : NSObject
#property (weak,nonatomic) IBOutlet UIView *someOutlet;
#end
// MySub.h
#import "MySuper.h"
#interface MySub : MySuper
// stuff for my sub
#end
Now both MySuper and MySub can refer to someOutlet
For "protected", something like this:
// MySuper.h
#interface MySuper : NSObject
// only public stuff here
#end
// MySuper-protected.h
#interface MySuper ()
#property (weak,nonatomic) IBOutlet UIView *someOutlet;
#end
// MySuper.m
#import "MySuper.h"
#import "MySuper-protected.h"
// MySub.h
// same as simple case
// MySub.m
#import "MySub.h"
#import "MySuper-protected.h"

Answer 3

Finally, i was able to achieve this by using this way!!!!
In my subclass i changed the method to:
-(void)printSuperClassiBouletObject:(SuperClassA*)superClassObj
and in my super class i am calling this way:
SubClassB *obj = [SubClassB new];
[obj printSuperClassiBouletObject:self];
And in my subclass i was access the super class objects and its variable from the super class instance it self.
Thanks for all the help !!!!!! :-)