Blocksの循環参照 Objective-CのBlocksの循環参照に関する僕なりのベストプラクティス http://blog.katty.in/2612 上記の記事を参考にしたコード

FPAntiCircularReferenceBlockPractice.h

#import <Foundation/Foundation.h>

#import "FPCommon.h"


typedef void (^FPWeakTargetBlock)(typeof_weak_target self);


@interface FPAntiCircularReferenceBlockPractice : NSObject

- (void)setTarget:(typeof_target)target
            block:(FPWeakTargetBlock)block;

- (void)run;

@end

FPAntiCircularReferenceBlockPractice.m

#import "FPAntiCircularReferenceBlockPractice.h"


@interface FPAntiCircularReferenceBlockPractice ()
@property (nonatomic, weak) typeof_target     target;
@property (nonatomic, copy) FPWeakTargetBlock block;
@end

@implementation FPAntiCircularReferenceBlockPractice

- (void)dealloc
{
    FPCurrent();
}

- (void)setTarget:(typeof_target)target
            block:(FPWeakTargetBlock)block
{
    self.target = target;
    self.block  = block;
}

- (void)run
{
    FPBlocks(self.block)(self.target);
}

@end

FPCommon.h

#import <Foundation/Foundation.h>


// これらの型やマクロを用意することでXcodeの補完機能を利用して編集ミスを無くすことができる。
// selfという名前の型を定義するのが危なそうな場合はself_にする。
typedef id self;
#define typeof_target self
#define typeof_weak_target __typeof(self)

// Utility
#define FPCurrent() NSLog(@"%@ %@", self.class, NSStringFromSelector(_cmd))
#define FPBlocks(block) !(block) ? 0 : (block)

FPPracticeViewController.h

#import <UIKit/UIKit.h>


@interface FPPracticeViewController : UIViewController

@end

FPPracticeViewController.m

#import "FPPracticeViewController.h"

#import "FPAntiCircularReferenceBlockPractice.h"


@interface FPPracticeViewController ()
@property (nonatomic, strong) FPAntiCircularReferenceBlockPractice *practice;
@property (nonatomic, assign) NSInteger runCount;
@end

@implementation FPPracticeViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        [self makePractice];
    }
    return self;
}

- (void)dealloc
{
    FPCurrent();
}

- (void)makePractice
{
    self.practice = [[FPAntiCircularReferenceBlockPractice alloc] init];
    [self.practice setTarget:self block:^(typeof(self) self) {
        self.runCount++;
        [self runPractice];
    }];
}

- (void)runPractice
{
    FPCurrent();
    NSLog(@"count %@", @(self.runCount));
}

- (IBAction)touchedPractice
{
    [self.practice run];
}

@end