NotificationController provides a better way to use NSNotificationCenter on iOS and Mac.

Features:

• compile-time warnings for retain-cycles in the block-based API
• prevention from registration for the same notification more than once
• automatic unregistration from notifications in -dealloc

We encourage you to learn about the underlying implementation from the blog post.

Fully working example is as simple as:

__weak typeof(self) weakSelf = self;

self.notificationController = [[MCSNotificationController alloc] initWithObserver:self];
[self.notificationController addObserverForName:MCSNotification sender:nil queue:nil usingBlock:^(NSNotification *note) {
    [weakSelf doSomething];
}];

or

self.notificationController = MCSNotificationController(observer: self)
self.notificationController?.addObserverForName(name, sender: nil, queue: nil, usingBlock: {  [weak self] (_) -> Void in
    self.doSomething()
})

Above examples assume that there's a strongly held notificationController property on that object. Deregistration happens automatically on the controller's deallocation.

There's also a category on NSObject that creates a lazy-loaded mcs_notificationController property for you. So, Objective-C example can get even shorter:

__weak typeof(self) weakSelf = self;

[self.mcs_notificationController addObserverForName:MCSNotification sender:nil queue:nil usingBlock:^(NSNotification *note) {
    [weakSelf doSomething];
}];

That's all you have to do to safely use notifications with blocks. You should also see an example app and comments in the header.

• iOS 7 and above
• OS X 10.9 and above

Install with Carthage:

github "macoscope/NotificationController"

or with CocoaPods:

pod "NotificationController"

Then import with: #import <NotificationController/MCSNotificationController.h>

Published under the MIT License. Copyright (c) 2015 Macoscope sp. z o.o.