feat: added handler feature for missing translations #23

ng2-translate.ts

@@ -4,6 +4,7 @@ import {TranslateService} from './src/translate.service';
 export * from './src/translate.pipe';
 export * from './src/translate.service';
 export * from './src/translate.parser';
+export * from './src/missingtranslationhandler.interface';
 
 export default {
   pipes: [TranslatePipe],

package.json

@@ -52,7 +52,7 @@
     "es6-shim": "~0.33.3",
     "reflect-metadata": "0.1.2",
     "rxjs": "5.0.0-beta.0",
-    "zone.js": "~0.5.10"
+    "zone.js": "0.5.11"
   },
   "czConfig": {
     "path": "node_modules/cz-conventional-changelog"

src/missingtranslationhandler.interface.ts

@@ -0,0 +1,3 @@
+export interface MissingTranslationHandler {
+      handle(key: string): void;
+}

src/translate.service.ts

@@ -6,6 +6,7 @@ import 'rxjs/add/operator/share';
 import 'rxjs/add/operator/map';
 
 import {Parser} from './translate.parser';
+import {MissingTranslationHandler} from './missingtranslationhandler.interface';
 
 interface TranslateLoader {
     getTranslation(lang: string): any;
@@ -68,6 +69,11 @@ export class TranslateService {
     private defaultLang: string;
     private langs: Array<string>;
     private parser: Parser = new Parser();
+
+    /**
+     * Handler for missing translations
+     */
+    private missingTranslationHandler: MissingTranslationHandler;
 
     constructor(private http: Http) {
         this.useStaticFilesLoader();
@@ -183,6 +189,10 @@ export class TranslateService {
                 let translations: any = this.parser.flattenObject(this.translations[this.defaultLang]);
                 res = this.parser.interpolate(translations[key], interpolateParams);
             }
+
+            if (!res && this.missingTranslationHandler) {
+              this.missingTranslationHandler.handle(key);
+            }
 
             return res || key;
         };
@@ -218,5 +228,9 @@ export class TranslateService {
         this.currentLang = lang;
         this.onLangChange.emit({lang: lang, translations: this.translations[lang]});
     }
+
+    public setMissingTranslationHandler(handler: MissingTranslationHandler) {
+        this.missingTranslationHandler = handler;
+    }
 
 }

tests/translate.service.spec.ts

@@ -6,6 +6,7 @@ import {
 } from "angular2/http";
 import {MockBackend, MockConnection} from "angular2/http/testing";
 import {TranslateService} from '../src/translate.service';
+import {MissingTranslationHandler} from '../src/missingtranslationhandler.interface';
 
 export function main() {
 
@@ -151,5 +152,35 @@ export function main() {
                 done();
             });
         });
+
+        function prepareMissingTranslationHandler() {
+          class Missing implements MissingTranslationHandler {
+                handle(key: string) {}
+            }
+            let handler = new Missing();
+            spyOn(handler, 'handle');
+
+            translate.setMissingTranslationHandler(handler);
+
+            return handler;
+        }
+
+        it('should use the MissingTranslationHandler when the key does not exist', () => {
+            prepareStaticTranslate();
+            let handler = prepareMissingTranslationHandler();
+
+            translate.get('nonExistingKey').subscribe(() => {
+                expect(handler.handle).toHaveBeenCalledWith('nonExistingKey');
+            });
+        });
+
+        it('should not call the MissingTranslationHandler when the key exists', () => {
+            let handler = prepareMissingTranslationHandler();
+            prepareStaticTranslate();
+
+            translate.get('TEST').subscribe(() => {
+                expect(handler.handle).not.toHaveBeenCalled();
+            });
+        });
     });
 }