Issue when subscribing to NSUserDefaults on iOS

[tonyarnold]

NB: This has been discussed to some extent on Twitter, but I think it's worth tracking as an issue.

While it's possible to subscribe to NSUserDefaults values using the following syntax:

[[[NSUserDefaults standardUserDefaults] rac_subscribableForKeyPath:kDWKUserDefaultRequirePasscodeToUnlockKey onObject:self] subscribeNext:^(NSNumber *newValue) {
    ...
}]];

I'm seeing the following crash report from users once the app is compiled for release and distributed:

https://gist.github.com/f7131bf0fa8a18ea884b

Officially, NSUserDefaults has no KVO support on either platform (on OS X and Cocoa proper, you can use the NSUserDefaultsController's values object for KVO support).

I'm hoping this is some kind of simple deallocation issue, but I haven't found a way around this yet (nor a reproducible test case).

[jspahrsummers]

Are you still seeing crash reports on the latest master? Pull request #29 addressed some issues around deallocation of the KVO trampolines (though it doesn't have anything specific to NSUserDefaults).

[tonyarnold]

Thanks @jspahrsummers — I haven't seen the issue after pulling the latest changes.

[jspahrsummers]

🤘

[jwilling]

Thanks! Fixed it for me as well. ✨