iphone global settings - best way to implement it?

Question

Hi all,

I'd like to have some settings that I can access from anywhere in my app. Is there a best way to implement this? Right now I'm just sticking properties in my app delegate, then access them with:

ClientAppDelegate *appDelegate = (ClientAppDelegate *)[[UIApplication sharedApplication] delegate];
settingValue = appDelegate.setting;

Answer 1

Use NSUserDefaults—they're a reliable, simple way of storing application settings, and even persist between app launches.

Answer 2

If they are persistent, use NSUserDefaults. If they are not, wrap them in a class and give every class that needs them a pointer. In every case you should probably make it possible to change the connection to the configuration object so that (1) the dependency gets obvious (“aha, this code’s behaviour depends on the configuration”) and (2) you can supply a custom configuration object for testing purposes. There is a great series of articles about singletons, coupling and testing by Miško Hevery. You can start by the post called Singletons are Pathological Liars and follow up from there, it will do good to your design.