Static library and internationalization

Question

I have a question regarding static libraries. I need to localize some text inside my library. So I created a bundle where I put my different localized files. Then, I created a function like this :

NSString *MyLocalizedString(NSString* key, NSString* comment)
{
    static NSBundle* bundle = nil;
    if (!bundle)
    {
        NSString* path = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"MyStaticLib.bundle"];
        bundle = [[NSBundle bundleWithPath:path] retain];
    }

    return [bundle localizedStringForKey:key value:@"" table:nil];
}

But when I use it, it always return the english localized string (besides my phone langage is French). I do not know why.

Answer 1

I've got the very same issue when doing the exactly same: I've a static library and a companion bundle file with image, localized string, etc..

I've figured out that seems that the static can't figure out the correct device localization (I'm sorry but I wasn't able to find the reason of this issue) and I've fixed by doing this:

@implementation NSBundle (KiosKitAdditions)

+ (NSBundle *)kioskitBundle
{
    static NSBundle* kioskitBundle = nil;
    static dispatch_once_t predicate;
    dispatch_once(&predicate, ^{

        NSString *libraryBundlePath = [[NSBundle mainBundle] pathForResource:KKBundleName
                                                                      ofType:@"bundle"];

        NSBundle *libraryBundle = [[NSBundle bundleWithPath:libraryBundlePath] retain];
        NSString *langID        = [[NSLocale preferredLanguages] objectAtIndex:0];
        NSString *path          = [libraryBundle pathForResource:langID ofType:@"lproj"];
        kioskitBundle           = [[NSBundle bundleWithPath:path] retain];
    });
    return kioskitBundle;
}

@end

As you can see I have created a category of NSBundle with a Class method that act very similar to [NSBundle mainBundle] and that return me the correct bundle for the static libray so I can use it everywhere I want, for example:

#define KKLocalizedString(key) NSLocalizedStringFromTableInBundle(key, @"Localizable", [NSBundle kioskitBundle], @"")

The code is very simple first I find the path for the static library bundle, find the current device language and then I create a new NSBundle whose path is library_path/device_language.lproj .

A drawback of this approach is that you need to alway localize all of your asset and this can be a pain if you have a lot image in your bundle (but I think this is unlikely).

If you don't want to adopt my category approach you can change your code like this:

NSString *MyLocalizedString(NSString* key, NSString* comment)
{
    static NSBundle* bundle = nil;
    if (!bundle)
    {
        NSString *libraryBundlePath = [[NSBundle mainBundle] pathForResource:@"MyStaticLib"
                                                                      ofType:@"bundle"];

        NSBundle *libraryBundle = [NSBundle bundleWithPath:libraryBundlePath];
        NSString *langID        = [[NSLocale preferredLanguages] objectAtIndex:0];
        NSString *path          = [libraryBundle pathForResource:langID ofType:@"lproj"];
        bundle                  = [[NSBundle bundleWithPath:path] retain];

    }

    return [bundle localizedStringForKey:key value:@"" table:nil];
}

Answer 2

I had to modify Luca's answer to get it working how I wanted. My problem was very similar: Using my bundled localized strings from the consuming application didn't resolve to correct [lang].lproj folder. In my case, I had an es.lproj folder I wanted to look up from. However, if the user sets their preferred langauge to es-MX, using [NSLocale preferredLanguages] objectAtIndex:0] will try to find the es-MS.lproj folder, which doesn't exist.

@implementation NSBundle (CCPAdditions)

+ (NSBundle *)CCPBundle
{
    static NSBundle* corePaymentBundle = nil;
    static dispatch_once_t predicate;
    dispatch_once(&predicate, ^{

        NSString *libraryBundlePath = [[NSBundle mainBundle] pathForResource:@"ClipCorePayments"
                                                                      ofType:@"bundle"];

        NSBundle *libraryBundle = [NSBundle bundleWithPath:libraryBundlePath];

        for (NSString *langID in [NSLocale preferredLanguages])
        {
            NSString *path = [libraryBundle pathForResource:langID ofType:@"lproj"];
            if (path)
            {
                corePaymentBundle           = [NSBundle bundleWithPath:path];
                break;
            }
        }
    });

    return corePaymentBundle;
}

@end

This iterates through the preferred language list, and checks to see if that path exists. If es-MX.lproj is missing, it will next check es.lproj, etc. and eventually finds en.lproj if nothing else is there.