Blocks in C and Objective-C are downright magical. They make coding easier and potentially quicker, not to mention faster on the front end with multithreading and Grand Central Dispatch. BlocksKit hopes to facilitate this kind of programming by removing some of the annoying - and, in some cases, impeding - limits on coding with blocks.

BlocksKit is a framework andr static library for iOS 4.0+ and Mac OS X 10.6+.

What's In The Box

  • Performing blocks on an NSObject.
  • Key-value observation (<NSKeyValueObserving>) with block handlers.
  • Associated objects in an Obj-C API. (Not directly block-related.)
  • NSArray, NSSet, NSDictionary, and NSIndexSet filtering and enumeration.
  • Macros for more quickly typing out the above.
  • NSInvocation creation using a block.
  • NSTimer block execution.
  • Both delegation and block callbacks on NSURLConnection.
  • Delegate callback for NSCache.

UIKit Extensions

  • UIAlertView, UIActionSheet with block callbacks and convenience methods.
  • Block initializers for UIControl and UIBarButtonItem
  • Block-backed initializers for UIGestureRecognizer.
  • On-touch utilities for UIView.
  • Block callbacks for MFMailComposeViewController and MFMessageComposeViewController.
  • Delegate alternative for UIWebView.


Production Build

This is recommended, but we don't have a release yet.

  • Download a release of BlocksKit or clone the repository and build a framework target. Locate BlocksKit.framework in the Products folder of the Files and Folders pane.
  • Move BlocksKit.framework to your project's folder. From there, simply drag it into your project.
  • Insert #import <BlocksKit/BlocksKit.h> in any header file, including your project's prefix header.

Development Build

If you want to work with a new, untagged checkout of BlocksKit, you can build against a library target.

  • Clone the repository.
  • In Xcode 4, click-and-drag (or add using File > Add Files to Project) the BlocksKit project into a project or workspace.
  • In the build phases of a target, add libBlocksKit.a to the "Target Dependencies" and "Link Binary with Libraries".
  • In the build settings, change "All Linker Flags" to -ObjC -all_load and "Header Search Paths" to $(BUILT_PRODUCTS_DIR)/../BlocksKit/**.
    • If you are using Xcode 4.2 with the iOS 5.0 SDK on a non-ARC target, set "All Linker Flags" to -ObjC -all_load -fobjc-arc.
  • In any header file, insert #import "BlocksKit/BlocksKit.h". It is not recommended to insert the import statement in your project prefix, as it might will break Xcode 4's Code Sense for the entire project.


Documentation is exhaustive and done using AppleDoc.

An Xcode 4 compatible documentation set is available using this Atom link. Add it to Xcode 4's preferences and it'll download automatically.

You can also view the documentation online at my website.


BlocksKit is created and maintained by Zachary Waldowski under the MIT license (hello, nice to meet you). All of the included code is licensed either under BSD, MIT, or is in the public domain. The project itself is free for use in any and all projects. You can use BlocksKit in any project, public or private, with or without attribution.

Unsure about your rights? Read more.


BlocksKit takes, repurposes, fiddles with, and groups together a variety of block-related code generally found here on GitHub.

The following people (in alphabetical order) have their code lovingly enshrined in BlocksKit:

Individual credits exist in the header files and, consequently, in the documentation.