I think an elegant solution is what Mr. Erik Ralston propose on his Github repository
https://gist.github.com/eralston/8010285
this are the essential steps:
create a category for NSArray and NSMutableArray
in the implementation create a convenience class with a weak property. Your category will assign the objects to this weak property.
.h
#import <Foundation/Foundation.h>@interface NSArray(WeakArray)- (__weak id)weakObjectForIndex:(NSUInteger)index;-(id<NSFastEnumeration>)weakObjectsEnumerator;@end@interface NSMutableArray (FRSWeakArray)-(void)addWeakObject:(id)object;-(void)removeWeakObject:(id)object;-(void)cleanWeakObjects;@end.m
#import "NSArray+WeakArray.h"@interface WAArrayWeakPointer : NSObject@property (nonatomic, weak) NSObject *object;@end@implementation WAArrayWeakPointer@end@implementation NSArray (WeakArray)-(__weak id)weakObjectForIndex:(NSUInteger)index{ WAArrayWeakPointer *ptr = [self objectAtIndex:index]; return ptr.object;}-(WAArrayWeakPointer *)weakPointerForObject:(id)object{ for (WAArrayWeakPointer *ptr in self) { if(ptr) { if(ptr.object == object) { return ptr; } } } return nil;}-(id<NSFastEnumeration>)weakObjectsEnumerator{ NSMutableArray *enumerator = [[NSMutableArray alloc] init]; for (WAArrayWeakPointer *ptr in self) { if(ptr && ptr.object) { [enumerator addObject:ptr.object]; } } return enumerator;}@end@implementation NSMutableArray (FRSWeakArray)-(void)addWeakObject:(id)object{ if(!object) return; WAArrayWeakPointer *ptr = [[WAArrayWeakPointer alloc] init]; ptr.object = object; [self addObject:ptr]; [self cleanWeakObjects];}-(void)removeWeakObject:(id)object{ if(!object) return; WAArrayWeakPointer *ptr = [self weakPointerForObject:object]; if(ptr) { [self removeObject:ptr]; [self cleanWeakObjects]; }}-(void)cleanWeakObjects{ NSMutableArray *toBeRemoved = [[NSMutableArray alloc] init]; for (WAArrayWeakPointer *ptr in self) { if(ptr && !ptr.object) { [toBeRemoved addObject:ptr]; } } for(WAArrayWeakPointer *ptr in toBeRemoved) { [self removeObject:ptr]; }}@end