feat(translateService): implements proposedLanguage()

src/translate.js

@@ -41,6 +41,7 @@ angular.module('pascalprecht.translate').provider('$translate', ['$STORAGE_KEY',
       $preferredLanguage,
       $fallbackLanguage,
       $uses,
+      $nextLang,
       $storageFactory,
       $storageKey = $STORAGE_KEY,
       $storagePrefix,
@@ -620,6 +621,19 @@ angular.module('pascalprecht.translate').provider('$translate', ['$STORAGE_KEY',
       return $fallbackLanguage;
     };
 
+    /**
+     * @ngdoc function
+     * @name pascalprecht.translate.$translate#proposedLanguage
+     * @methodOf pascalprecht.translate.$translate
+     *
+     * @description
+     * Returns the language key of language that is currently loaded asynchronously.
+     *
+     * @return {string} language key
+     */
+    $translate.proposedLanguage = function () {
+      return $nextLang;
+    };
 
     /**
      * @ngdoc function
@@ -662,6 +676,7 @@ angular.module('pascalprecht.translate').provider('$translate', ['$STORAGE_KEY',
       if (!$translationTable[key]) {
 
         pendingLoader = true;
+        $nextLang = key;
 
         $injector.get($loaderFactory)(angular.extend($loaderOptions, {
           key: key

test/unit/translateServiceSpec.js

@@ -808,4 +808,47 @@ describe('pascalprecht.translate', function () {
       });
     });
   });
+
+  describe('proposedLanguage()', function () {
+
+    var $translate;
+
+    beforeEach(module('pascalprecht.translate', function ($translateProvider, $provide) {
+
+      $provide.factory('customLoader', function ($q, $timeout) {
+        return function (options) {
+          var deferred = $q.defer();
+
+          $timeout(function () {
+            deferred.resolve({});
+          }, 1000);
+
+          return deferred.promise;
+        };
+      });
+
+      $translateProvider.useLoader('customLoader');
+      $translateProvider.preferredLanguage('en');
+    }));
+
+    beforeEach(inject(function (_$translate_) {
+      $translate = _$translate_;
+    }));
+
+    it('should have a method proposedLanguage()', function () {
+      expect($translate.proposedLanguage).toBeDefined();
+    });
+
+    it('should be a use function ', function () {
+      expect(typeof $translate.proposedLanguage).toBe('function');
+    });
+
+    it('should return a string', function () {
+      expect(typeof $translate.proposedLanguage()).toBe('string');
+    });
+
+    it('should return proposedLanguage', function () {
+      expect($translate.proposedLanguage()).toEqual('en');
+    });
+  });
 });