Develop Reference

How to localize User Consent API prompt text on Android

I'd like to localize or event better change the prompt text of User Consent API.
Default behavior:
So instead of Allow example to read the message below and enter the code I want it to be translated in other languages, based on my app's locale not based on device's locale.

This view's translation is handled by the library gms:play-services-auth-api-phone.
Didn 't find any information in their documentation explaining how to customize the message displayed in the bottomSheetView.
About the language of the message, it should update automatically depending on the phone's language.
Since you're receiving an intent from another app, chances are that you won't be able to 'force' a locale sadly.
The only thing you could try is to "force" the Locale on the Android part in your FlutterActivity but note that it could have unpredicted consequences over your app, and I really doubt it'll work.
private void setLocale(Locale locale){
SharedPrefUtils.saveLocale(locale); // optional - Helper method to save the selected language to SharedPreferences in case you might need to attach to activity context (you will need to code this)
Resources resources = getResources();
Configuration configuration = resources.getConfiguration();
DisplayMetrics displayMetrics = resources.getDisplayMetrics();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1){
configuration.setLocale(locale);
} else{
configuration.locale=locale;
}
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.N){
getApplicationContext().createConfigurationContext(configuration);
} else {
resources.updateConfiguration(configuration,displayMetrics);
}
}
Code retrieved from this StackOverflow post, credit to the author.

Android App Bundle with in-app locale change

I've a problem with AAB when I need to change the app locale from within the app itself(i.e. have the language change setting inside the app), the issue is that the AAB gives me only my device languages resources, for example:
my device has English and French languages installed in it, so AAb gives me only the resources for English and French,
but from within the app itself there is a choice to switch the language between English, French, and Indonesian,
in that case, when changing the language to English or French everything is working perfectly, but when changing it to Indonesian, the app simply enters a crash loop as it keep looking for Indonesian language but it can't find.
The problem here is that even if I restarted the app, it enters the crash loop again as the app is still looking for the missing language resources, and here the only solution is to clear cash or reinstall which are the solutions that the normal user won't go through.
Just to mention it, this is how I change the locale through the app:
// get resources
Resources res = context.getResources();
// create the corresponding locale
Locale locale = new Locale(language); // for example "en"
// Change locale settings in the app.
android.content.res.Configuration conf = res.getConfiguration();
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1) {
conf.setLocale(locale);
conf.setLayoutDirection(locale);
} else {
conf.locale = locale;
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
context.getApplicationContext().createConfigurationContext(conf);
}
res.updateConfiguration(conf, null);
P.S. The app is working perfectly when build it as APK.

Edit:
The PlayCore API now supports downloading the strings for another language on-demand:
https://developer.android.com/guide/playcore/feature-delivery/on-demand#lang_resources
Alternative solution (discouraged):
You can disable the splitting by language by adding the following configuration in your build.gradle
android {
bundle {
language {
// Specifies that the app bundle should not support
// configuration APKs for language resources. These
// resources are instead packaged with each base and
// dynamic feature APK.
enableSplit = false
}
}
}
This latter solution will increase the size of the app.

This is not possible with app bundles: Google Play only downloads resources when the device's selected languages change.
You'll have to use APKs if you want to have an in app language picker.

Details of downloading the language on demand can be found here
https://android-developers.googleblog.com/2019/03/the-latest-android-app-bundle-updates.html
In your app’s build.gradle file:
dependencies {
// This dependency is downloaded from the Google’s Maven repository.
// So, make sure you also include that repository in your project's build.gradle file.
implementation 'com.google.android.play:core:1.10.0'
// For Kotlin users also add the Kotlin extensions library for Play Core:
implementation 'com.google.android.play:core-ktx:1.8.1'
...
}
Get a list of installed languages
val splitInstallManager = SplitInstallManagerFactory.create(context)
val langs: Set<String> = splitInstallManager.installedLanguages
Requesting additional languages
val installRequestBuilder = SplitInstallRequest.newBuilder()
installRequestBuilder.addLanguage(Locale.forLanguageTag("pl"))
splitInstallManager.startInstall(installRequestBuilder.build())
Check above link for full details

After many hours I was finally able to use the on-demand language with the new PlayCore API.
Step 1.) As the user changes the language, you need to first check whether the language is already available, if not then download the language
private void changeLocale(final String languageSelected){
SplitInstallManager splitInstallManager = SplitInstallManagerFactory.create(PlayAgainstComputer.this);
final Set<String> installedLangs = splitInstallManager.getInstalledLanguages();
if(installedLangs.contains(languageSelected)){ // checking if lang already available
Toast.makeText(PlayAgainstComputer.this,"Done! The language settings will take effect, once you restart the app!").show();
}
else{
SplitInstallRequest request =
SplitInstallRequest.newBuilder()
.addLanguage(Locale.forLanguageTag(languageSelected))
.build();
splitInstallManager.startInstall(request);
splitInstallManager.registerListener(new SplitInstallStateUpdatedListener() {
#Override
public void onStateUpdate(#NonNull SplitInstallSessionState splitInstallSessionState) {
if(splitInstallSessionState.status() == SplitInstallSessionStatus.INSTALLED){
Toast.makeText(PlayAgainstComputer.this,"Download complete! The language settings will take effect, once you restart the app!").show();
}
}
});
}}
Step2.) The downloaded languages must be installed when the user starts the app. which is done in the attchBaseContext() method
#Override
protected void attachBaseContext(Context base) {
super.attachBaseContext(base);
SplitCompat.install(this); // It will install all the downloaded langauges into the app
}
Step 3.) You need to tell the Activity to use the chosen language. Following code should be placed before setContentView(R.layout.layout); of that activity
String selectedLanguage = getFromPrefernceOrWhereEverYouSavedIt(); // should be 2 letters. like "de", "es"
Locale locale = new Locale(selectedLanguage);
Locale.setDefault(locale);
Resources resources = getResources();
Configuration config = new Configuration(resources.getConfiguration());
config.locale = locale;
resources.updateConfiguration(config,
getBaseContext().getResources().getDisplayMetrics());
Done!
Please Note
When a user (who chose a non-default/downloaded language) updates the app, that language needs to be downloaded again into the app, so make sure you handle that in your code.
when I used activity.recreate(); after the download finished (to automatically refresh the app for new language) I faced some problems, that is why I used Toast to ask the user to manually restart the app. but you can try other methods
I also noticed some other inconsistencies (even sometimes faced memory leak because of SplitCompat.install(this);) with this method, so make sure you test and optimize it according to your code.

After I set Locale.setDefault(locale), how can I get back the phone langage?

I use this snippet to allow the user to set his favorite locale in the appplication:
Locale locale = new Locale(newLan);
Locale.setDefault(locale);
Configuration config = getBaseContext().getResources().getConfiguration();
config.locale = locale;
getBaseContext().getResources().updateConfiguration(config,getBaseContext().getResources().getDisplayMetrics());
Problem is that I would like to write a setting that would allow the user to get back to the default langage of the phone.
How is it possible?
Because after using the snippet above and imagine user chose French, I cannot get back the phone locale (which might be english for instance)

I just tried this, my phone locale is US, the toast is shown in french but in the log I still see US, maybe if you don't set the new locale as default it works anyway?
Locale locale = new Locale("fr");
//Locale.setDefault(locale);
Configuration config = getBaseContext().getResources().getConfiguration();
config.locale = locale;
getBaseContext().getResources().updateConfiguration(config,getBaseContext().getResources().getDisplayMetrics());
Toast.makeText(this, android.R.string.cancel, Toast.LENGTH_LONG).show();
Log.d("LOCALE", Locale.getDefault().getCountry());
I've seen using Locale.setDefault() in other questions and answers, now I'm wondering, why would you be required to set the default Locale manually? If that was necessary, wouldn't it be done in updateConfiguration() anyway? this answer is also interesting

How about:
Saving current locale to shared preferences
Force to whatever you want
Use the shared preferences value to move back to original locale

Firstly this bit of code config.locale = locale; is deprecated, you should use config.setLocale(locale);
Have you tried getting the current device locale with Locale.getDefault().getDisplayLanguage();, and set it once the user chooses the default locale to be the selected language of your application with your code snippet?

In https://stackoverflow.com/a/34675427/519334 I solved the issue "go back to device-languge" by remembering the device-language in a static variable before any app-changes to locale have been taken place:
public class Global {
public static final Locale systemLocale = Locale.getDefault();
}

Locale during unit test on Android

I have some code I want to test. I want to check if a String is properly composed out of various strings that I have in resources. The challenge here is to deal with multiple translations in my resources. I know that locale can be an issue when testing a desktop application and that it is recommended that you create locale-independent tests.
I've found that you can set the locale programatically, but it was not recommended (see Change language programmatically in Android). While this question is aimed at changing locale at runtime when running an app normally, I was wondering if there was a better solution to my problem.

If it's just for testing, then you can change the locale programmatically without any issues. It will change the configuration of your app and you will be able to test your code with the new locale. It has the same effect as if a user has changed it. If you want to automate your tests, you can write a script that changes locale using adb shell as described here, and launch your tests afterwards.
Here is an example of testing translations of word "Cancel" for English, German and Spanish locales:
public class ResourcesTestCase extends AndroidTestCase {
private void setLocale(String language, String country) {
Locale locale = new Locale(language, country);
// here we update locale for date formatters
Locale.setDefault(locale);
// here we update locale for app resources
Resources res = getContext().getResources();
Configuration config = res.getConfiguration();
config.locale = locale;
res.updateConfiguration(config, res.getDisplayMetrics());
}
public void testEnglishLocale() {
setLocale("en", "EN");
String cancelString = getContext().getString(R.string.cancel);
assertEquals("Cancel", cancelString);
}
public void testGermanLocale() {
setLocale("de", "DE");
String cancelString = getContext().getString(R.string.cancel);
assertEquals("Abbrechen", cancelString);
}
public void testSpanishLocale() {
setLocale("es", "ES");
String cancelString = getContext().getString(R.string.cancel);
assertEquals("Cancelar", cancelString);
}
}
Here are the execution results in Eclipse:
Android O update.
When running in Android O method Locale.setDefault(Category.DISPLAY, locale) shall be used (see behaviour changes for more detail).

The current accepted answer didn't help me.
But #Dennis's comment helped to solve the Problem for me.
Use Robolectric and override the locale by specifying a resource qualifier.
Add for example #Config(qualifiers="de-port") for the German language.
#Test
#Config(qualifiers = "de-port")
fun testGetLocaleGerman(){ ... }
Robolectrics Documentation

How to change which language will be loaded in Android for debug purposes?

I want to test how my application looks like, and force it to load some specific language, but I don't want and don't need it in production code, so it can be some switch in eclipse or some code in onCreate.
EDIT: I don't want to manually change this, I want code what will let me to automate my tests.

I did something like this in my onCreate method:
// LOCALE
if (DEBUG == true)
{
Misc.setLocale(this, "en"); // change "en" to "fr" for french
}
And here is setLocale method:
public static void setLocale(Context context, String language)
{
final Locale locale = new Locale(language);
Locale.setDefault(locale);
final Configuration config = new Configuration();
config.locale = locale;
context.getResources().updateConfiguration(config,
context.getResources().getDisplayMetrics());
}
Now I can really fast change languages, I don't need to bother with emulator or settings in my device. I also can't forget about this, because of checking for DEBUG value.

Just change the language on your emulator. If you need to run automated tests against particular languages, just define separate AVDs configured for each language.
Any code you call is just going to force the same thing to happen as if you had changed the settings.