Merge pull request #89 from shiv19/master

feat(LanguageSwitch): Added support to dynamically switch language on Android

Author: EddyVerbruggen

README.md

@@ -178,11 +178,88 @@ Keys starting with `ios.info.plist.` are used to localize iOS properties:
 ### How to change the language dynamically at runtime?
 This plugin uses the native capabilities of each platform, language selection is therefore made by the OS.
 
-On iOS you can programmatically override this language since plugin version 4.2.0 by doing this:
+## On iOS you can programmatically override this language since plugin version 4.2.0 by doing this:
 
 ```typescript
 import { overrideLocale } from "nativescript-localize/localize";
-const localeOverriddenSuccessfully = overrideLocale("en-GB"); // or "nl-NL", etc
+const localeOverriddenSuccessfully = overrideLocale("en-GB"); // or "nl-NL", etc (or even just the part before the hyphen)
+```
+
+## On Android you can programatically override this language since plugin version 4.2.1 by doing this:
+
+In your app.ts / main.ts / app.js
+
+```ts
+import { on, launchEvent } from '@nativescript/core/application';
+import { androidLaunchEventLocalizationHandler } from 'nativescript-localize/localize';
+
+on(launchEvent, (args) => {
+  if (args.android) {
+    androidLaunchEventLocalizationHandler();
+  }
+});
+```
+
+And in your settings page where user chooses the language:
+
+```ts
+import { overrideLocale } from "nativescript-localize/localize";
+const localeOverriddenSuccessfully = overrideLocale("en-GB"); // or "nl-NL", etc (or even just the part before the hyphen)
+```
+
+> **Important:** In both cases, after calling override Locale, you must ask the user to restart the app
+
+For Example:
+
+```ts
+import { android as _android } from '@nativescript/core/application';
+import { overrideLocale } from 'nativescript-localize/localize';
+
+alert({
+  title: 'Switch Language',
+  message: 'The application needs to be restarted to change language',
+  okButtonText: 'Quit!'
+}).then(() => {
+  L.localize.overrideLocale(selectedLang);
+  if (isAndroid) {
+    _android.foregroundActivity.finish();
+  } else {
+    exit(0);
+  }
+});
+```
+
+> **Important:** In case you are using [Android app bundle](https://docs.nativescript.org/tooling/publishing/android-app-bundle) to release your android app, add this to
+> App_Resources/Android/app.gradle to make sure all lanugages are bundled in the split apks
+
+```groovy
+android {
+
+  // there maybe other code here //
+
+  bundle {
+    language {
+      enableSplit = false
+    }
+  }
+}
+```
+
+> **Tip:** you can get the default language on user's phone by using this
+
+```ts
+import { device } from '@nativescript/core/platform';
+
+console.log("user's language is", device.language.split('-')[0]);
+```
+
+> **Tip:** overrideLocale method stores the language in a special key in app-settings,
+> you can access it like this,
+
+```ts
+import { getString } from '@nativescript/core/application-settings'; 
+
+console.log(getString('__app__language__')); // only available after the first time you use overrideLocale(langName);
 ```
 
 ## Troubleshooting

publish/package-lock.json

@@ -1,6 +1,7 @@
-import { localize, overrideLocale } from "./localize";
+import { localize, overrideLocale, androidLaunchEventLocalizationHandler } from "./localize";
 
 module.exports = localize;
 module.exports.default = localize;
 module.exports.localize = localize;
 module.exports.overrideLocale = overrideLocale;
+module.exports.androidLaunchEventLocalizationHandler = androidLaunchEventLocalizationHandler;

src/index.ts

@@ -1,8 +1,13 @@
 import { vsprintf } from "sprintf-js";
-import * as utils from "utils/utils";
+import * as utils from "tns-core-modules/utils/utils";
+import { getString, setString } from 'tns-core-modules/application-settings';
+import { isAndroid } from 'tns-core-modules/platform';
+import { android as _android } from 'tns-core-modules/application';
 
 import { encodeKey } from "./resource";
 
+declare var java: any;
+
 const getResources = (function () {
   let resources = null;
   return function () {
@@ -24,7 +29,22 @@ export function localize(key: string, ...args: string[]): string {
   return vsprintf(localizedString, args);
 }
 
+export function androidLaunchEventLocalizationHandler() {
+  const lang = getString('__app__language__', 'none');
+  if (lang !== 'none' && isAndroid) {
+    const locale = new java.util.Locale(lang);
+    java.util.Locale.setDefault(locale);
+
+    const resources = _android.context.getResources();
+    const configuration = resources.getConfiguration();
+    configuration.locale = locale;
+
+    resources.updateConfiguration(configuration, resources.getDisplayMetrics());
+  }
+}
+
 export function overrideLocale(locale: string): boolean {
-  console.log("overrideLocale is not (yet) implemented on Android");
-  return false;
+  setString('__app__language__', locale.substring(0, 2));
+
+  return true;
 }

src/localize.android.ts

@@ -1,2 +1,3 @@
 export declare function localize(key: string, ...args: string[]): string;
 export declare function overrideLocale(locale: string): boolean;
+export declare function androidLaunchEventLocalizationHandler(): void;

src/localize.d.ts

@@ -2,6 +2,7 @@ import { vsprintf } from "sprintf-js";
 
 import { convertAtSignToStringSign } from "./placeholder";
 import { encodeKey } from "./resource";
+import { setString } from "tns-core-modules/application-settings";
 
 let bundle;
 
@@ -19,6 +20,10 @@ export function localize(key: string, ...args: string[]): string {
   return vsprintf(convertAtSignToStringSign(localizedString), args);
 }
 
+export function androidLaunchEventLocalizationHandler() {
+  // dummy
+}
+
 export function overrideLocale(locale: string): boolean {
   const path = NSBundle.mainBundle.pathForResourceOfType(locale.substring(0, 2), "lproj");
 
@@ -29,5 +34,7 @@ export function overrideLocale(locale: string): boolean {
   bundle = NSBundle.bundleWithPath(path);
   NSUserDefaults.standardUserDefaults.setObjectForKey([locale], "AppleLanguages");
   NSUserDefaults.standardUserDefaults.synchronize();
+  setString('__app__language__', locale.substring(0, 2));
+
   return true;
 }

src/localize.ios.ts

@@ -1,7 +1,7 @@
 {
   "name": "nativescript-localize",
   "description": "Native internationalization plugin for NativeScript using native capabilities of each platform",
-  "version": "4.2.0",
+  "version": "4.2.1",
   "keywords": [
     "nativescript",
     "internationalization",
@@ -28,6 +28,10 @@
     {
       "name": "Brendan Ingham",
       "email": "[email protected]"
+    },
+    {
+      "name": "MultiShiv19",
+      "email": "[email protected]"
     }
   ],
   "main": "index.js",