Tracking block args of Objective-C method based on BlockHook
Switch branches/tags
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.


CI Status Carthage compatible GitHub release Twitter Follow


BlockTracker can track block arguments of a method. It's based on BlockHook.

📚 Article

追踪 Objective-C 方法中的 Block 参数对象

🌟 Features

  • Easy to use.
  • Keep your code clear.
  • Reserve the whole arguments.
  • Get return value.
  • Get invoke count.
  • Trace all block args of method.
  • Self-managed trackers.
  • Support Carthage.

🔮 Example

The sample project "BlockTrackerSample" just only support iOS platform.

🐒 How to use

You can track blocks in arguments. This method returns a BTTracker instance for more control. You can stop a BTTracker when you don't want to track it anymore.

- (void)viewDidLoad {
    [super viewDidLoad];
    // Begin Track
    BTTracker *tracker = [self bt_trackBlockArgOfSelector:@selector(performBlock:) callback:^(id  _Nullable block, BlockTrackerCallbackType type, NSInteger invokeCount, void * _Nullable * _Null_unspecified args, void * _Nullable result, NSArray<NSString *> * _Nonnull callStackSymbols) {
        NSLog(@"%@ invoke count = %ld", BlockTrackerCallbackTypeInvoke == type ? @"BlockTrackerCallbackTypeInvoke" : @"BlockTrackerCallbackTypeDead", (long)invokeCount);
    // invoke blocks
    __block NSString *word = @"I'm a block";
    [self performBlock:^{
        NSLog(@"add '!!!' to word");
        word = [word stringByAppendingString:@"!!!"];
    [self performBlock:^{
        NSLog(@"%@", word);
    // stop tracker in future
//    [tracker stop];
    // blocks will die

- (void)performBlock:(void(^)(void))block {
//    block();


Here is the log:

add '!!!' to word
BlockTrackerCallbackTypeInvoke invoke count = 1
I'm a block!!!
BlockTrackerCallbackTypeInvoke invoke count = 1
BlockTrackerCallbackTypeDead invoke count = 1
BlockTrackerCallbackTypeDead invoke count = 1

📲 Installation


Carthage is a decentralized dependency manager that builds your dependencies and provides you with binary frameworks.

You can install Carthage with Homebrew using the following command:

$ brew update
$ brew install carthage

To integrate BlockTracker into your Xcode project using Carthage, specify it in your Cartfile:

github "yulingtianxia/BlockTracker"

Run carthage update to build the framework and drag the built BlockTrackerKit.framework into your Xcode project.


After importing libffi, just add the two files BlockTracker.h/m to your project.

❤️ Contributed

  • If you need help or you'd like to ask a general question, open an issue.
  • If you found a bug, open an issue.
  • If you have a feature request, open an issue.
  • If you want to contribute, submit a pull request.

👨🏻‍💻 Author


👮🏻 License

BlockTracker is available under the MIT license. See the LICENSE file for more info.