User Defined Runtime Attributes and Associated Objects

Question

I'm currently trying to use User Defined Runtime Attributes in Xcode 6 with the following algorithm:

1. Add custom properties to UIView class using Associated Objects

   #define ASSOCIATED_OBJECT_GETTER_AND_SETTER(propertyType, propertyName, propertyNameWithCapital, associationType)   \
   -(void)set##propertyNameWithCapital:(propertyType)_value                                                            \
   {                                                                                                                   \
       objc_setAssociatedObject(self, @selector(propertyName), _value, associationType);                               \
   }                                                                                                                   \
   -(propertyType)propertyName                                                                                         \
   {                                                                                                                   \
       return objc_getAssociatedObject(self, @selector(propertyName));                                                 \
   }                                                                                                                   \                                       
   
   @interface eMyTags : NSObject
   @property (nonatomic) NSString* name;
   @end
   
   @implementation eMyTags
   @synthesize name;
   @end
   
   @interface UIView (MyTags)
   @property (nonatomic) eMyTags* myTags;
   @property (nonatomic) NSString* myName;
   @end
   
   @implementation UIView (MyTags)
   @dynamic myTags, myName;
   ASSOCIATED_OBJECT_GETTER_AND_SETTER(eMyTags*, myTags, MyTags, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
   ASSOCIATED_OBJECT_GETTER_AND_SETTER(NSString*, myName, MyName, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
   @end
   

2. Set values of these properties through Xcode storyboard

3. Access these properties in code during runtime

   -(void)viewDidLoad
   {
       [super viewDidLoad];
       NSLog(@"myName: %@", view.myName);
       NSLog(@"myTags.name: %@", view.myTags.name);
   }
   

When i compile and run the output is:

myName: bla
myTags.name: (null)

So why myTags.name is not set? What did i miss? Can't i set User Defined Runtime Attributes of custom types?

Answer 1

Well myTags is not allocated in the memory and nor initialised. On the other hand, the value @"bla" is a string literal which is actually an instance of an NSString and points to a location in memory.