[ADF-3630] fix i18n fallback behaviour (#3851)

* fix i18n fallback behaviour

* update tests

* update tests

* configuration fixes

* test configuration fix

lib/core/core.module.ts

@@ -100,8 +100,8 @@ import { ViewUtilService } from './viewer/services/view-util.service';
 import { LoginDialogService } from './services/login-dialog.service';
 import { ExternalAlfrescoApiService } from './services/external-alfresco-api.service';
 
-export function createTranslateLoader(http: HttpClient, logService: LogService) {
-    return new TranslateLoaderService(http, logService);
+export function createTranslateLoader(http: HttpClient) {
+    return new TranslateLoaderService(http);
 }
 
 export function providers() {

lib/core/karma.conf.js

@@ -28,11 +28,11 @@ module.exports = function (config) {
 
             {pattern: 'lib/core/i18n/**/en.json', included: false, served: true, watched: false},
 
-            {pattern: 'lib/core/./**/*.ts', included: false, served: true, watched: false},
+            {pattern: 'lib/core/**/*.ts', included: false, served: true, watched: false},
             {pattern: 'lib/core/assets/**/*.svg', included: false, served: true, watched: false},
 
             {pattern: 'lib/config/app.config.json', included: false, served: true, watched: false},
-            {pattern: 'lib/core//viewer/assets/fake-test-file.pdf', included: false, served: true, watched: false},
+            {pattern: 'lib/core/viewer/assets/fake-test-file.pdf', included: false, served: true, watched: false},
             {pattern: 'lib/core/viewer/assets/fake-test-file.txt', included: false, served: true, watched: false},
             {
                 pattern: 'lib/core//viewer/assets/fake-test-password-file.pdf',

lib/core/mock/translation.service.mock.ts

@@ -34,17 +34,13 @@ export class TranslationMock implements TranslationService {
         onLangChange: new EventEmitter<LangChangeEvent>()
     };
 
-    addTranslationFolder() {
+    addTranslationFolder() {}
 
-    }
+    onTranslationChanged() {}
 
-    onTranslationChanged() {
+    use(): any {}
 
-    }
-
-    use(): any {
-
-    }
+    loadTranslation() {}
 
     get(key: string | Array<string>, interpolateParams?: Object): Observable<string | any> {
         return of(key);

lib/core/services/translate-loader.service.ts

@@ -19,11 +19,10 @@ import { HttpClient } from '@angular/common/http';
 import { Injectable } from '@angular/core';
 import { Response } from '@angular/http';
 import { TranslateLoader } from '@ngx-translate/core';
-import { Observable, forkJoin } from 'rxjs';
+import { Observable, forkJoin, throwError } from 'rxjs';
 import { ComponentTranslationModel } from '../models/component.model';
 import { ObjectUtils } from '../utils/object-utils';
-import { LogService } from './log.service';
-import { map } from 'rxjs/operators';
+import { map, catchError } from 'rxjs/operators';
 
 @Injectable()
 export class TranslateLoaderService implements TranslateLoader {
@@ -33,8 +32,7 @@ export class TranslateLoaderService implements TranslateLoader {
     private providers: ComponentTranslationModel[] = [];
     private queue: string [][] = [];
 
-    constructor(private http: HttpClient,
-                private logService: LogService) {
+    constructor(private http: HttpClient) {
     }
 
     registerProvider(name: string, path: string) {
@@ -59,21 +57,16 @@ export class TranslateLoaderService implements TranslateLoader {
             if (!this.isComponentInQueue(lang, component.name)) {
                 this.queue[lang].push(component.name);
 
-                const loader = Observable.create(observer => {
-                    const translationUrl = `${component.path}/${this.prefix}/${lang}${this.suffix}?v=${Date.now()}`;
+                const translationUrl = `${component.path}/${this.prefix}/${lang}${this.suffix}?v=${Date.now()}`;
 
-                    this.http.get(translationUrl).pipe(map((res: Response) => {
-                        component.json[lang] = res;
-                    })).subscribe((result) => {
-                        observer.next(result);
-                        observer.complete();
-                    }, () => {
-                        observer.next('');
-                        observer.complete();
-                    });
-                });
-
-                observableBatch.push(loader);
+                observableBatch.push(
+                    this.http.get(translationUrl).pipe(
+                        map((res: Response) => {
+                            component.json[lang] = res;
+                        }),
+                        catchError(() => throwError(`Error loading ${translationUrl}`))
+                    )
+                );
             }
         });
 
@@ -114,7 +107,7 @@ export class TranslateLoaderService implements TranslateLoader {
     }
 
     getTranslation(lang: string): Observable<any> {
-        let observableBatch = this.getComponentToFetch(lang);
+        const observableBatch = this.getComponentToFetch(lang);
 
         return Observable.create(observer => {
             if (observableBatch.length > 0) {
@@ -126,13 +119,14 @@ export class TranslateLoaderService implements TranslateLoader {
                         }
                         observer.complete();
                     },
-                    (err: any) => {
-                        this.logService.error(err);
+                    (err) => {
+                        observer.error(err);
                     });
             } else {
                 let fullTranslation = this.getFullTranslationJSON(lang);
                 if (fullTranslation) {
                     observer.next(fullTranslation);
+                    observer.complete();
                 }
             }
         });

lib/core/services/translation.service.ts

@@ -62,22 +62,29 @@ export class TranslationService {
     addTranslationFolder(name: string = '', path: string = '') {
         if (!this.customLoader.providerRegistered(name)) {
             this.customLoader.registerProvider(name, path);
+
             if (this.userLang) {
-                this.translate.getTranslation(this.userLang).subscribe(() => {
-                        this.translate.use(this.userLang);
-                        this.onTranslationChanged(this.userLang);
-                    }
-                );
+                this.loadTranslation(this.userLang, this.defaultLang);
             } else {
-                this.translate.getTranslation(this.defaultLang).subscribe(() => {
-                        this.translate.use(this.defaultLang);
-                        this.onTranslationChanged(this.defaultLang);
-                    }
-                );
+                this.loadTranslation(this.defaultLang);
             }
         }
     }
 
+    loadTranslation(lang: string, fallback?: string) {
+        this.translate.getTranslation(lang).subscribe(
+            () => {
+                this.translate.use(lang);
+                this.onTranslationChanged(lang);
+            },
+            () => {
+                if (fallback && fallback !== lang) {
+                    this.loadTranslation(fallback);
+                }
+            }
+        );
+    }
+
     /**
      * Triggers a notification callback when the translation language changes.
      * @param lang The new language code