How to force NSLocalizedString to use a specific language

Question

On iPhone NSLocalizedString returns the string in the language of the iPhone. Is it possible to force NSLocalizedString to use a specific language to have the app in a different language than the device ?

Answer 1

NSLocalizedString() (and variants thereof) access the "AppleLanguages" key in NSUserDefaults to determine what the user's settings for preferred languages are. This returns an array of language codes, with the first one being the one set by the user for their phone, and the subsequent ones used as fallbacks if a resource is not available in the preferred language. (on the desktop, the user can specify multiple languages with a custom ordering in System Preferences)

You can override the global setting for your own application if you wish by using the setObject:forKey: method to set your own language list. This will take precedence over the globally set value and be returned to any code in your application that is performing localization. The code for this would look something like:

[[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObjects:@"de", @"en", @"fr", nil] forKey:@"AppleLanguages"];
[[NSUserDefaults standardUserDefaults] synchronize]; //to make the change immediate

This would make German the preferred language for your application, with English and French as fallbacks. You would want to call this sometime early in your application's startup. You can read more about language/locale preferences here: Internationalization Programming Topics: Getting the Current Language and Locale