feat(TranslateService): adding new getBrowserLang method

README.md

@@ -184,6 +184,7 @@ Or use the `TranslatePipe` in any template:
 - `set(key: string, value: string, lang?: string)`: Sets the translated value of a key
 - `reloadLang(lang: string): Observable<string|Object>`: Calls resetLang and retrieves the translations object for the current loader
 - `resetLang(lang: string)`: Removes the current translations for this lang. /!\ You will have to call `use`, `reloadLang` or `getTranslation` again to be able to get translations
+- `getBrowserLang(): string | undefined`: Returns the current browser lang if available, or undefined otherwise 
 
 #### Write & use your own loader
 If you want to write your own loader, you need to create a class that implements `TranslateLoader`.

src/translate.service.ts

@@ -20,6 +20,11 @@ export interface LangChangeEvent {
     translations: any;
 }
 
+declare interface Window {
+    navigator: any;
+}
+declare var window: Window;
+
 export abstract class MissingTranslationHandler {
     /**
      * A function that handles missing translations.
@@ -114,7 +119,7 @@ export class TranslateService {
 
         if (typeof pending !== "undefined") {
             // on init set the currentLang immediately
-            if(!this.currentLang) {
+            if (!this.currentLang) {
                 this.currentLang = lang;
             }
             pending.subscribe((res: any) => {
@@ -343,4 +348,18 @@ export class TranslateService {
     public resetLang(lang: string): void {
         this.translations[lang] = undefined;
     }
+
+    public getBrowserLang(): string | undefined {
+        if (typeof window === 'undefined' || typeof window.navigator === 'undefined') {
+            return undefined;
+        }
+        let browserLang: any;
+        if (typeof window.navigator['languages'] !== 'undefined' && window.navigator['languages'].length > 0) {
+            browserLang = window.navigator['languages'][0].indexOf('-') !== -1 || window.navigator['languages'].length < 2 ? window.navigator['languages'][0] : window.navigator['languages'][1];
+        } else {
+            browserLang = window.navigator['language'] || window.navigator['browserLanguage'];
+        }
+
+        return browserLang && browserLang.length ? browserLang.split('-')[0] : undefined; // use navigator lang if available
+    }
 }

tests/translate.service.spec.ts

@@ -267,6 +267,12 @@ export function main() {
 
             expect(translate.getLangs()).toEqual(['en', 'pl']);
         });
+
+        it('should be able to get the browserLang', () => {
+            let browserLang = translate.getBrowserLang();
+            expect(browserLang).toBeDefined();
+            expect(typeof browserLang === 'string').toBeTruthy();
+        });
     });
 
     describe('MissingTranslationHandler', () => {