fix(fallback): Allowing chomsky to work with just the base translatio…

…n file

demo/src/demo.ts

@@ -52,10 +52,12 @@ chomsky.onLocaleChange.subscribe((locale: string) => {
 const US_LOCALE = 'en-US';
 const FR_LOCALE = 'fr-FR';
 const GB_LOCALE = 'en-GB';
+const MISSING_LOCALE = 'en-NOPE';
 
 // Swap Locales
 chomsky.use(US_LOCALE);
 chomsky.use(FR_LOCALE);
+chomsky.use(MISSING_LOCALE);
 chomsky.use(GB_LOCALE).subscribe(() => {
     // Load US again (should not fire XHR requests)
     chomsky.use(US_LOCALE);

package.json

@@ -1,6 +1,6 @@
 {
   "name": "chomsky",
-  "version": "2.1.7",
+  "version": "2.1.8",
   "description": "A simple ES6 i18n engine.",
   "main": "lib/index.js",
   "typings": "build/main/index.d.ts",
@@ -98,4 +98,4 @@
   "dependencies": {
     "tslib": "^1.5.0"
   }
-}
+}

src/lib/chomsky.ts

@@ -4,6 +4,7 @@ import { Subject } from 'rxjs/Subject';
 import 'rxjs/add/observable/of';
 import 'rxjs/add/observable/combineLatest';
 import 'rxjs/add/operator/share';
+import 'rxjs/add/observable/fromPromise';
 // APP
 import { Loader } from './loader';
 import { Formats, IFormatDefaults } from './formats';
@@ -79,8 +80,6 @@ export class Chomsky {
     private dictionaryManager = new DictionaryManager();
     // Custom formats based on the locale
     private formats = new Formats();
-    // Current pending call to fetch translations
-    private pending: any;
     // Object for default replacements, so users don't have to pass around each time
     private defaultReplacements: any = {};
     // Handle for when the locale changes
@@ -230,22 +229,21 @@ export class Chomsky {
     private getTranslations(locale: string): Observable<any> {
         // Split out the language code from the locale
         let languageCode = (locale.split('-')[0] || '').toLowerCase();
-        // Cue up two observables to grab the locale and the fallback locale
-        // en-US - locale (en-US) / fallback (en)
-        let translations = this.translationFetcher(locale);
-        let fallbackTranslations = this.translationFetcher(languageCode);
-        // Combine the two observables and share the same subscription
-        this.pending = Observable.combineLatest(translations, fallbackTranslations).share();
-        // Subscribe to the result
-        this.pending.subscribe(result => {
-            this.applyLanguage(locale, result[0], result[1]);
-        }, err => {
-            console.error('[Chomsky] - Fetching Translations Error:', err);
-        }, () => {
-            this.pending = undefined;
-        });
-
-        return this.pending;
+        // Fetch the fallback language first
+        return Observable.fromPromise(new Promise<any>((resolve, reject) => {
+            this.translationFetcher(languageCode).then(fallbackTranslations => {
+                this.translationFetcher(locale).then(translations => {
+                    this.applyLanguage(locale, translations, fallbackTranslations);
+                    resolve(true);
+                }, error => {
+                    this.applyLanguage(locale, {}, fallbackTranslations);
+                    resolve(true);
+                });
+            }, error => {
+                console.error(`[Chomsky] - Cannot find the base translation file! (${languageCode}):`, error);
+                resolve(false);
+            });
+        }));
     }
 
     private applyLanguage(locale: string, translations: any, fallbackTranslations: any): void {
@@ -270,7 +268,7 @@ export class Chomsky {
         this.onLocaleChange.next(locale);
     }
 
-    private translationFetcher(locale: string): Observable<string> {
+    private translationFetcher(locale: string): Promise<string> {
         return this.loader.load(`${this.location}${locale}.json`);
     }
 }

src/lib/dictionary-manager.ts

@@ -1,3 +1,6 @@
+// APP
+import { mergeDeep } from './object-assign-deep';
+
 export class DictionaryManager {
     private dictionaries: any = {};
 
@@ -10,6 +13,6 @@ export class DictionaryManager {
     }
 
     public add(locale: string, translations: any, fallbackTranslations: any): void {
-        this.dictionaries[locale] = Object.assign({}, fallbackTranslations, translations);
+        this.dictionaries[locale] = mergeDeep({}, fallbackTranslations, translations);
     }
 }

src/lib/loader.spec.ts

@@ -27,21 +27,21 @@ test('should have a method load', t => {
 
 test('load should properly load a json file', t => {
     let valid = { KEY: 'value' };
-    t.context.loader.load('/valid.json').subscribe(result => {
+    t.context.loader.load('/valid.json').then(result => {
         t.deepEqual(result, valid);
     });
     server.requests[0].respond(200, { 'Content-Type': 'application/json' }, JSON.stringify(valid));
 });
 
 test('load should reject with JSON parse fails', t => {
-    t.context.loader.load('/invalid.json').subscribe(() => { }, error => {
+    t.context.loader.load('/invalid.json').then(() => { }, error => {
         t.is(error, 'Parse Error: Invalid JSON');
     });
     server.requests[0].respond(200, { 'Content-Type': 'application/json' }, '["\t"]');
 });
 
 test('load should reject when 404 happens', t => {
-    t.context.loader.load('/404.json').subscribe(() => { }, error => {
+    t.context.loader.load('/404.json').then(() => { }, error => {
         t.is(error, 'Not Found');
     });
     server.requests[0].respond(404);

src/lib/loader.ts

@@ -1,7 +1,3 @@
-// Vendor
-import { Observable } from 'rxjs/Observable';
-import 'rxjs/add/observable/fromPromise';
-
 /**
  * @name Loader
  * @description Loader to load the JSON translation files via HTTP
@@ -16,8 +12,8 @@ export class Loader {
      * @returns {Observable<string>}
      * @memberOf Loader
      */
-    public load(url: string): Observable<string> {
-        return Observable.fromPromise(new Promise((resolve, reject) => {
+    public load(url: string): Promise<string> {
+        return new Promise((resolve, reject) => {
             let xhr = new XMLHttpRequest();
             xhr.open('GET', url);
 
@@ -38,6 +34,6 @@ export class Loader {
             };
 
             xhr.send();
-        }));
+        });
     }
 }