Justin on Auto Layout Debugging

Justin Williams shows how to use layoutDebuggingIdentifier to help when debugging auto layout in iOS 8.

This sounds very useful. It’s private API, so you can use it for debugging only, but that’s totally fine.

I might have taken an alternate approach with the code, though. Instead of NSSelectorFromString, the clang pragmas, and performSelector:​withObject:, I would have done this:

#if DEBUG
  NSString *identifier = @"Email Label";
  [self.emailLabel setValue:identifier forKey:​@"layoutDebuggingIdentifier"];
#endif

Not tested, but ought to work.