Refacto language + add navigator preferences

src/app/app.component.html

@@ -10,16 +10,6 @@
     >
       {{ 'app.user-manual' | translate }}
     </a>
-    <sbb-select
-      (selectionChange)="changeLocale($event.value)"
-      [value]="locale"
-      class="language-selector"
-    >
-      <sbb-option value="en">🇬🇧 English</sbb-option>
-      <sbb-option value="de">🇩🇪 Deutsch</sbb-option>
-      <sbb-option value="fr">🇫🇷 Français</sbb-option>
-      <!-- <sbb-option value="it">🇮🇹 Italiano</sbb-option> -->
-    </sbb-select>
   </sbb-app-chooser-section>
   <sbb-header-environment class="noprint" *ngIf="environmentLabel">{{
     environmentLabel
@@ -35,8 +25,8 @@
   </sbb-usermenu>
   <sbb-menu #menu="sbbMenu">
     <sbb-select
-      (selectionChange)="changeLocale($event.value)"
-      [value]="locale"
+      (selectionChange)="language = $event.value"
+      [value]="currentLanguage"
       class="language-selector language-selector-menu"
       (click)="$event.stopPropagation()"
       (keydown)="$event.stopPropagation()"

src/app/app.component.ts

@@ -11,6 +11,7 @@ import {NetzgrafikDto} from "./data-structures/business.data.structures";
 import {Operation} from "./models/operation.model";
 import {LabelService} from "./services/data/label.serivce";
 import {NodeService} from "./services/data/node.service";
+import {I18nService} from "./core/i18n/i18n.service";
 
 @Component({
   selector: "sbb-root",
@@ -20,9 +21,9 @@ import {NodeService} from "./services/data/node.service";
 export class AppComponent {
   readonly disableBackend = environment.disableBackend;
   readonly version = packageJson.version;
-  readonly locale = localStorage.getItem("locale");
   readonly environmentLabel = environment.label;
   readonly authenticated: Promise<unknown>;
+  protected currentLanguage: string = this.i18nService.language;
 
   projectInMenu: Observable<ProjectDto | null>;
 
@@ -46,6 +47,7 @@ export class AppComponent {
               private trainrunSectionService: TrainrunSectionService,
               private nodeService: NodeService,
               private labelService: LabelService,
+              private i18nService: I18nService,
             ) {
     if (!this.disableBackend) {
       this.authenticated = authService.initialized;
@@ -58,9 +60,16 @@ export class AppComponent {
     }
   }
 
-  changeLocale(locale: string) {
-    localStorage.setItem("locale", locale);
-    location.reload();
+  @Input()
+  get language() {
+    return this.currentLanguage;
+  }
+
+  set language(language: string) {
+    if (language !== this.currentLanguage) {
+      this.i18nService.setLanguage(language);
+      this.currentLanguage = language;
+    }
   }
 
   @Input()

src/app/core/i18n/i18n.module.ts

@@ -1,23 +1,23 @@
 import {NgModule, APP_INITIALIZER, LOCALE_ID} from "@angular/core";
 import {CommonModule} from "@angular/common";
 import {TranslatePipe} from "./translate.pipe";
-import {I18n} from "./i18n.service";
+import {I18nService} from "./i18n.service";
 
 @NgModule({
   declarations: [TranslatePipe], // Declare the pipe
   imports: [CommonModule],
   providers: [
-    I18n,
+    I18nService,
     { // Load locale data at app start-up
       provide: APP_INITIALIZER,
-      useFactory: (i18n: I18n) => () => i18n.setLocale(),
-      deps: [I18n],
+      useFactory: (i18nService: I18nService) => () => i18nService.setLanguage(),
+      deps: [I18nService],
       multi: true,
     },
     { // Set the runtime locale for the app
       provide: LOCALE_ID,
-      useFactory: (i18n: I18n) => i18n.locale,
-      deps: [I18n],
+      useFactory: (i18nService: I18nService) => i18nService.language,
+      deps: [I18nService],
     }
   ],
   exports: [TranslatePipe] // Export the pipe

src/app/core/i18n/i18n.service.ts

@@ -5,85 +5,94 @@ import {loadTranslations} from "@angular/localize";
 @Injectable({
     providedIn: "root",
   })
-  export class I18n {
-    locale = "en";
-    readonly allowedLocales = ["en", "fr", "de", "it"];
-    translations: any = {};
-
-    async setLocale() {
-      const userLocale = localStorage.getItem("locale");
-
-      // If the user has a preferred language stored in LocalStorage, use it.
-      if (userLocale && this.allowedLocales.includes(userLocale)) {
-        this.locale = userLocale;
-      } else {
-        localStorage.setItem("locale", this.locale);
-      }
-
-      // Use webpack magic string to only include required locale data
-      const localeModule = await import(
-        /* webpackInclude: /(en|de|fr|it)\.mjs$/ */
-        `/node_modules/@angular/common/locales/${this.locale}.mjs`
-      );
-      registerLocaleData(localeModule.default);
-
-      // Load translation file initially
-      await this.loadTranslations();
-    }
-
-    async loadTranslations() {
-      const localeTranslationsModule = await import(
-        `src/assets/i18n/${this.locale}.json`
-      );
-
-      // Ensure translations are flattened if necessary
-      this.translations = this.flattenTranslations(localeTranslationsModule.default);
-
-      // Load translations for the current locale at runtime
-      loadTranslations(this.translations);
+export class I18nService {
+  readonly allowedLanguages = ["en", "fr", "de", "it"];
+  private currentLanguage: string = this.getLanguageFromStorage() || this.detectNavigatorLanguage();
+  translations: any = {};
+
+  get language(): string {
+    return this.currentLanguage;
+  }
+
+  async setLanguage(language?: string) {
+    if (language && this.allowedLanguages.includes(this.language)) {
+      this.setLanguageToStorage(language);
+      this.currentLanguage = language;
     }
-
-    // Helper function to flatten nested translations
-    // nested JSON :
-    // {
-    //   "app": {
-    //     "login": "Login",
-    //     "models": {...}
-    //   }
-    // }
-    // flattened JSON :
-    // {
-    //   "app.login": "Login",
-    //   "app.models...": ...,
-    //   "app.models...": ...
-    // }
-    private flattenTranslations(translations: any): any {
-      const flattenedTranslations = {};
-
-      function flatten(obj, prefix = "") {
-        for (const key in obj) {
-          if (typeof obj[key] === "string") {
-            flattenedTranslations[prefix + key] = obj[key];
-          } else if (typeof obj[key] === "object") {
-            flatten(obj[key], prefix + key + ".");
-          }
+
+    const languageModule = await import(
+      /* webpackInclude: /(en|de|fr|it)\.mjs$/ */
+      `/node_modules/@angular/common/locales/${this.language}.mjs`
+    );
+    registerLocaleData(languageModule.default);
+
+    await this.loadTranslations();
+  }
+
+  private setLanguageToStorage(language: string) {
+    localStorage.setItem("i18nLng", language);
+  }
+
+  private getLanguageFromStorage(): string | null {
+    const lang = localStorage.getItem("i18nLng");
+    return this.allowedLanguages.includes(lang) ? lang : null;
+  }
+
+  private detectNavigatorLanguage(): string {
+    const navigatorLanguage = navigator.language.slice(0, 2);
+    return this.allowedLanguages.includes(navigatorLanguage) ? navigatorLanguage : this.allowedLanguages[0];
+  }
+
+  async loadTranslations() {
+    const languageTranslationsModule = await import(
+      `src/assets/i18n/${this.language}.json`
+    );
+
+    this.translations = this.flattenTranslations(languageTranslationsModule.default);
+    loadTranslations(this.translations);
+  }
+
+  // Helper function to flatten nested translations
+  // nested JSON :
+  // {
+  //   "app": {
+  //     "login": "Login",
+  //     "models": {...}
+  //   }
+  // }
+  // flattened JSON :
+  // {
+  //   "app.login": "Login",
+  //   "app.models...": ...,
+  //   "app.models...": ...
+  // }
+  private flattenTranslations(translations: any): any {
+    const flattenedTranslations = {};
+
+    function flatten(obj, prefix = "") {
+      for (const key in obj) {
+        if (typeof obj[key] === "string") {
+          flattenedTranslations[prefix + key] = obj[key];
+        } else if (typeof obj[key] === "object") {
+          flatten(obj[key], prefix + key + ".");
         }
       }
-
-      flatten(translations);
-      return flattenedTranslations;
     }
-
-    // Used for the pipe and allowing parameters
-    translate(key: string, params?: any): string {
-      let translation = this.translations[key] || key;
-
-      if (params) {
-        Object.keys(params).forEach(param => {
-          translation = translation.replace(`{$${param}}`, params[param]);
-        });
-      }
-
-      return translation;
+
+    flatten(translations);
+    return flattenedTranslations;
+  }
+
+  // Used for the pipe and allowing parameters
+  translate(key: string, params?: any): string {
+    let translation = this.translations[key] || key;
+
+    if (params) {
+      Object.keys(params).forEach(param => {
+        translation = translation.replace(`{$${param}}`, params[param]);
+      });
     }
+
+    return translation;
   }
+}

src/app/core/i18n/translate.pipe.ts

@@ -1,14 +1,14 @@
 import {Pipe, PipeTransform} from "@angular/core";
-import {I18n} from "./i18n.service";
+import {I18nService} from "./i18n.service";
 
 @Pipe({
   name: "translate",
   pure: false
 })
 export class TranslatePipe implements PipeTransform {
-  constructor(private i18n: I18n) {}
+  constructor(private i18nService: I18nService) {}
 
   transform(key: string, params?: any): string {
-    return this.i18n.translate(key, params);
+    return this.i18nService.translate(key, params);
   }
 }