Merge pull request #438 from lundin/master

fallbackLocale for translation (as GetMaterialApp config)

@@ -33,6 +33,8 @@ abstract class GetInterface {
   GetMaterialController getxController = GetMaterialController();
 
   Locale locale;
+  
+  Locale fallbackLocale;
 
   GlobalKey<NavigatorState> key = GlobalKey<NavigatorState>();
 

@@ -30,6 +30,7 @@ class GetMaterialApp extends StatelessWidget {
     this.darkTheme,
     this.themeMode = ThemeMode.system,
     this.locale,
+    this.fallbackLocale,
     this.localizationsDelegates,
     this.localeListResolutionCallback,
     this.localeResolutionCallback,
@@ -83,6 +84,7 @@ class GetMaterialApp extends StatelessWidget {
   final Map<String, Map<String, String>> translationsKeys;
   final Translations translations;
   final Locale locale;
+  final Locale fallbackLocale;
   final Iterable<LocalizationsDelegate<dynamic>> localizationsDelegates;
   final LocaleListResolutionCallback localeListResolutionCallback;
   final LocaleResolutionCallback localeResolutionCallback;
@@ -186,6 +188,10 @@ class GetMaterialApp extends StatelessWidget {
             Get.locale = locale;
           }
 
+          if (fallbackLocale != null) {
+            Get.fallbackLocale = fallbackLocale;
+          }
+
           if (translations != null) {
             Get.translations = translations.keys;
           } else if (translationsKeys != null) {
@@ -275,6 +281,16 @@ extension Trans on String {
         Get.translations[Get.locale.languageCode].containsKey(this)) {
       return Get.translations[Get.locale.languageCode][this];
       // If there is no corresponding language or corresponding key, return the key.
+    } else if (Get.fallbackLocale != null && Get.translations.containsKey(
+            "${Get.fallbackLocale.languageCode}_${Get.fallbackLocale.countryCode}") &&
+        Get.translations[
+                "${Get.fallbackLocale.languageCode}_${Get.fallbackLocale.countryCode}"]
+            .containsKey(this)) {
+      return Get.translations[
+              "${Get.fallbackLocale.languageCode}_${Get.fallbackLocale.countryCode}"]
+          [this];
+
+      // Checks if there is a callback language in the absence of the specific country, and if it contains that key.
     } else {
       return this;
     }