How to force NSLocalizedString to use a specific l

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

Swift Version:

NSUserDefaults.standardUserDefaults().setObject(["fr"], forKey: "AppleLanguages")
NSUserDefaults.standardUserDefaults().synchronize()

Answer 2

The trick to use specific language by selecting it from the app is to force the NSLocalizedString to use specific bundle depending on the selected language ,

here is the post i have written for this learning advance localization in ios apps

and here is the code of one sample app advance localization in ios apps

Answer 3

Do not use on iOS 9. This returns nil for all strings passed through it.

I have found another solution that allows you to update the language strings, w/o restarting the app and compatible with genstrings:

Put this macro in the Prefix.pch:

#define currentLanguageBundle [NSBundle bundleWithPath:[[NSBundle mainBundle] pathForResource:[[NSLocale preferredLanguages] objectAtIndex:0] ofType:@"lproj"]]

and where ever you need a localized string use:

NSLocalizedStringFromTableInBundle(@"GalleryTitleKey", nil, currentLanguageBundle, @"")

To set the language use:

[[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObject:@"de"] forKey:@"AppleLanguages"];

Works even with consecutive language hopping like:

NSLog(@"test %@", NSLocalizedStringFromTableInBundle(@"NewKey", nil, currentLanguageBundle, @""));
[[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObject:@"fr"] forKey:@"AppleLanguages"];
NSLog(@"test %@", NSLocalizedStringFromTableInBundle(@"NewKey", nil, currentLanguageBundle, @""));
[[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObject:@"it"] forKey:@"AppleLanguages"];
NSLog(@"test %@", NSLocalizedStringFromTableInBundle(@"NewKey", nil, currentLanguageBundle, @""));
[[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObject:@"de"] forKey:@"AppleLanguages"];
NSLog(@"test %@", NSLocalizedStringFromTableInBundle(@"NewKey", nil, currentLanguageBundle, @""));

Answer 4

In file .pch to define:

#define currentLanguageBundle [NSBundle bundleWithPath:[[NSBundle mainBundle] pathForResource:[[NSLocale preferredLanguages] objectAtIndex:0] ofType:@"lproj"]]


#define NSLocalizedString(str,nil) NSLocalizedStringFromTableInBundle(str, nil, currentLanguageBundle, @"")

Answer 5

This function will try to get localized string for current language and if it's not found it will get it using english language.

- (NSString*)L:(NSString*)key
{
    static NSString* valueNotFound = @"VALUE_NOT_FOUND";
    static NSBundle* enBundle = nil;

    NSString* pl = [NSLocale preferredLanguages][0];
    NSString* bp = [[NSBundle mainBundle] pathForResource:pl ofType:@"lproj"];
    NSBundle* b = [NSBundle bundleWithPath:bp];

    NSString* s = [b localizedStringForKey:key value:valueNotFound table:nil];
    if ( [s isEqualToString:valueNotFound] ) {
        if ( !enBundle ) {
            bp = [[NSBundle mainBundle] pathForResource:@"en" ofType:@"lproj"];
            enBundle = [NSBundle bundleWithPath:bp];
        }
        s = [enBundle localizedStringForKey:key value:key table:nil];
    }

    return s;
}

Answer 6

Based on Tudorizer's answer to change language without leaving or restarting the application.

Instead of a macro, use a class for accessing the preferred language in order to check if a specific language code is present.

Below is a class used to obtain the current language bundle that is working for iOS 9:

@implementation OSLocalization

+ (NSBundle *)currentLanguageBundle
{
    // Default language incase an unsupported language is found
    NSString *language = @"en";

    if ([NSLocale preferredLanguages].count) {
        // Check first object to be of type "en","es" etc
        // Codes seen by my eyes: "en-US","en","es-US","es" etc

        NSString *letterCode = [[NSLocale preferredLanguages] objectAtIndex:0];

        if ([letterCode rangeOfString:@"en"].location != NSNotFound) {
            // English
            language = @"en";
        } else if ([letterCode rangeOfString:@"es"].location != NSNotFound) {
            // Spanish
            language = @"es";
        } else if ([letterCode rangeOfString:@"fr"].location != NSNotFound) {
            // French
            language = @"fr";
        } // Add more if needed
    }

    return [NSBundle bundleWithPath:[[NSBundle mainBundle] pathForResource:language ofType:@"lproj"]];
}

/// Check if preferred language is English
+ (BOOL)isCurrentLanguageEnglish
{
    if (![NSLocale preferredLanguages].count) {
        // Just incase check for no items in array
        return YES;
    }

    if ([[[NSLocale preferredLanguages] objectAtIndex:0] rangeOfString:@"en"].location == NSNotFound) {
        // No letter code for english found
        return NO;
    } else {
        // Tis English
        return YES;
    }
}

/*  Swap language between English & Spanish
 *  Could send a string argument to directly pass the new language
 */
+ (void)changeCurrentLanguage
{
    if ([self isCurrentLanguageEnglish]) {
        [[NSUserDefaults standardUserDefaults] setObject:@[@"es"] forKey:@"AppleLanguages"];
    } else {
        [[NSUserDefaults standardUserDefaults] setObject:@[@"en"] forKey:@"AppleLanguages"];
    }
}
@end

Use the class above to reference a string file / image / video / etc:

// Access a localized image
[[OSLocalization currentLanguageBundle] pathForResource:@"my_image_name.png" ofType:nil]
// Access  a localized string from Localizable.strings file
NSLocalizedStringFromTableInBundle(@"StringKey", nil, [OSLocalization currentLanguageBundle], @"comment")

Change language in-line like below or update the "changeCurrentLanguage" method in the class above to take a string parameter referencing the new language.

[[NSUserDefaults standardUserDefaults] setObject:@[@"es"] forKey:@"AppleLanguages"];