how to release copy property added using category in objective C?

Question

I have added a copy property to UITableViewCell using category as shown below

NSString const *key = @"CellSelectedBlockKey";

@interface UITableViewCell (CellSelectionBlock)
@property (nonatomic, copy) CellSelectedBlock cellSelectedBlock;
@end

@implementation UITableViewCell (CellSelectionBlock)

- (void)setCellSelectedBlock:(void(^)(UITableView *table, NSIndexPath *indexpath))cellSelectedBlock
{
    objc_setAssociatedObject(self, &key, cellSelectedBlock, OBJC_ASSOCIATION_COPY_NONATOMIC);
}

- (CellSelectedBlock)cellSelectedBlock
{
    return objc_getAssociatedObject(self, &key);
}
@end

How would I clear memory (release), this property as I cannot overite dealloc method for this.

I'll appreciate any help on this. Any suggestion on best way to add property to an existing class without subclassing.

Answer 1

An associated object set with a strong-reference associated object policy (OBJC_ASSOCIATION_RETAIN, OBJC_ASSOCIATION_RETAIN_NONATOMIC, OBJC_ASSOCIATION_COPY, or OBJC_ASSOCIATION_COPY_NONATOMIC) are automatically released when a new value is set (or nil is set to clear) for the same key, or when the parent object is deallocated, just like with retain/copy properties, or with a strong reference in ARC.