localization - Localizing strings in iOS: default (fallback) language?

Question

Is there a way to set a default language to be used when the device UI language is not supported by an app?

Example: My app is localized into English and German:

// en.lproj:
"POWER_TO_THE_PEOPLE_BTN" = "Power";
"POWER_PLUG_BTN" = "Power";

// de.lproj:
"POWER_TO_THE_PEOPLE_BTN"  = "Macht";
"POWER_PLUG_BTN" = "Spannung";

Now, if I run the app on a device with UI language set to Italian the app will use the key strings POWER_TO_THE_PEOPLE_BTN and POWER_PLUG_BTN.

There must be a way to specify a default (fallback) language to be used by the application in such a case.

From the above example it should be clear that using the English string as a key will not work.

The only option I see right now is to use NSLocalizedStringWithDefaultValue instead of NSLocalizedString.

Answer 1

To avoid all those lengthy syntax and more having more descriptive var name for translators, I derived my own helper method L() for translation and falling back to English

NSString * L(NSString * translation_key) {
    NSString * s = NSLocalizedString(translation_key, nil);
    if (![[[NSLocale preferredLanguages] objectAtIndex:0] isEqualToString:@"en"] && [s isEqualToString:translation_key]) {
    NSString * path = [[NSBundle mainBundle] pathForResource:@"en" ofType:@"lproj"];
    NSBundle * languageBundle = [NSBundle bundleWithPath:path];
    s = [languageBundle localizedStringForKey:translation_key value:@"" table:nil];
    }
    return s;
}

My Localizable.strings would look like this

"SOME_ACTION_BUTTON" = "Do action";

So in my code, i would use L(@"SOME_ACTION_BUTTON") to get the correct string

Though sometime the key is longer than the translation itself HELP_BUTTON_IN_NAV_BAR = 'Help' but it saves me a lot of time explaining what it is to whoever is helping me doing the translation