Intlayerを使ったAngularの国際化（i18n）入門

import { Locales, type IntlayerConfig } from "intlayer";const config: IntlayerConfig = {  internationalization: {    locales: [      Locales.ENGLISH,      Locales.FRENCH,      Locales.SPANISH,      // 他のロケール    ],    defaultLocale: Locales.ENGLISH,  },};export default config;

import { prepareIntlayer, watch } from "@intlayer/chokidar";import { getConfiguration, logger } from "@intlayer/config";import type { Plugin } from "esbuild";const intlayerPlugin: Plugin = {  name: "intlayer-esbuild-plugin",  setup(build) {    const configuration = getConfiguration();    let isWatching = false;    build.onStart(async () => {      logger("Intlayer esbuild プラグインが開始されました", {        level: "info",      });      if (build.initialOptions.watch && !isWatching) {        logger("ウォッチモードが有効です。ウォッチャーを開始します...", {          level: "info",        });        watch(configuration);        isWatching = true;      }      try {        await prepareIntlayer(configuration);      } catch (error) {        logger(`Intlayer esbuild プラグインでエラーが発生しました: ${error}`, {          level: "error",        });      }    });  },};export default intlayerPlugin;

import { Component, signal } from "@angular/core";import { useIntlayer } from "angular-intlayer";@Component({  selector: "app-hello-world",  standalone: true,  template: `    <h1>{{ content().title }}</h1>    <div class="card">      <button type="button" (click)="increment()">        {{ content().count }} {{ count() }}      </button>      <p [innerHTML]="content().edit"></p>    </div>    <p class="read-the-docs">{{ content().readTheDocs }}</p>  `,})export class HelloWorldComponent {  content = useIntlayer("helloworld");  count = signal(0);  increment() {    this.count.update((value) => value + 1);  }}

import { Component } from "@angular/core";import { CommonModule } from "@angular/common";import { getLocaleName } from "intlayer";import { useLocale } from "angular-intlayer";import { FormsModule } from "@angular/forms";@Component({  selector: "app-locale-switcher",  standalone: true,  imports: [CommonModule, FormsModule],  template: `    <div class="locale-switcher">      <select [ngModel]="locale()" (ngModelChange)="changeLocale($event)">        <option *ngFor="let loc of availableLocales" [value]="loc">          {{ getLocaleName(loc) }}        </option>      </select>    </div>  `,})export class LocaleSwitcherComponent {  localeInfo = useLocale();  locale = this.localeInfo.locale;  availableLocales = this.localeInfo.availableLocales;  // テンプレートで getLocaleName を公開する  getLocaleName = getLocaleName;  changeLocale(newLocale: string) {    this.localeInfo.setLocale(newLocale);  }}次に、このコンポーネントを `app.component.ts` で使用します。```typescript fileName="src/app/app.component.ts"import { Component } from "@angular/core";import { HelloWorldComponent } from "./hello-world.component";import { LocaleSwitcherComponent } from "./components/locale-switcher.component";@Component({  selector: "app-root",  standalone: true,  imports: [HelloWorldComponent, LocaleSwitcherComponent],  template: `    <div>      <app-locale-switcher />      <a href="https://vite.dev" target="_blank">        <img src="/vite.svg" class="logo" alt="Vite ロゴ" />      </a>      <a href="https://angular.dev/" target="_blank">        <img          src="/assets/angular.svg"          class="logo angular"          alt="Angular ロゴ"        />      </a>    </div>    <app-hello-world />  `,})export class AppComponent {}

import { Routes } from "@angular/router";import { configuration, localeFlatMap } from "intlayer";import { HomeComponent } from "./home/home.component";import { RootComponent } from "./root/root.component";const { defaultLocale } = configuration.internationalization;export const routes: Routes = [  localeFlatMap((localizedData) => [    {      path: `${localizedData.urlPrefix}`,      component: RootComponent,      data: { locale: localizedData.locale },    },    {      path: `${localizedData.urlPrefix}/home`,      component: HomeComponent,      data: { locale: localizedData.locale },    },  ]),  { path: "**", redirectTo: `/${defaultLocale}/home` },];

import { ApplicationConfig } from "@angular/core";import { provideRouter } from "@angular/router";import { routes } from "./app.routes";export const appConfig: ApplicationConfig = {  providers: [provideRouter(routes)],};

import { Component, inject } from "@angular/core";import { CommonModule } from "@angular/common";import { Router } from "@angular/router";import { getLocaleName, getLocalizedUrl } from "intlayer";import { useLocale } from "angular-intlayer";import { FormsModule } from "@angular/forms";@Component({  selector: "app-locale-switcher",  standalone: true,  imports: [CommonModule, FormsModule],  template: `    <div class="locale-switcher">      <select [ngModel]="locale()" (ngModelChange)="changeLocale($event)">        <option *ngFor="let loc of availableLocales" [value]="loc">          {{ getLocaleName(loc) }}        </option>      </select>    </div>  `,})export class LocaleSwitcherComponent {  private router = inject(Router);  localeInfo = useLocale({    onLocaleChange: (newLocale) => {      const currentPath = this.router.url;      const localizedPath = getLocalizedUrl(currentPath, newLocale);      this.router.navigateByUrl(localizedPath);    },  });  locale = this.localeInfo.locale;  availableLocales = this.localeInfo.availableLocales;  getLocaleName = getLocaleName;  changeLocale(newLocale: string) {    this.localeInfo.setLocale(newLocale);  }}### （オプション）ステップ9: HTMLの言語属性と方向属性を切り替えるアプリケーションが複数の言語をサポートしている場合、`<html>`タグの`lang`属性と`dir`属性を現在のロケールに合わせて更新することが重要です。これを自動的に処理するサービスを作成できます。```typescript fileName="src/app/services/i18n-html-attributes.service.ts"import { Injectable, effect } from "@angular/core";import { useLocale } from "angular-intlayer";import { getHTMLTextDir } from "intlayer";@Injectable({  providedIn: "root",})export class I18nHtmlAttributesService {  private localeInfo = useLocale();  constructor() {    effect(() => {      const newLocale = this.localeInfo.locale();      if (newLocale) {        document.documentElement.lang = newLocale;        document.documentElement.dir = getHTMLTextDir(newLocale);      }    });  }  // このメソッドは、サービスが初期化されることを保証するためにアプリのルートコンポーネントで呼び出すことができます。  init() {}}

import { Component, inject } from "@angular/core";// ... その他のインポートimport { I18nHtmlAttributesService } from "./services/i18n-html-attributes.service";@Component({  // ...})export class AppComponent {  constructor() {    inject(I18nHtmlAttributesService).init();  }}

import { Directive, Input, HostBinding, inject } from "@angular/core";import { getLocalizedUrl } from "intlayer";import { useLocale } from "angular-intlayer";@Directive({  selector: "a[appLocalizedLink]",  standalone: true,})export class LocalizedLinkDirective {  @Input("href") originalHref: string = "";  private localeInfo = useLocale();  @HostBinding("href")  get localizedHref(): string {    const locale = this.localeInfo.locale();    const isExternalLink = /^https?:\/\//.test(this.originalHref);    if (isExternalLink || !this.originalHref) {      return this.originalHref;    }    return getLocalizedUrl(this.originalHref, locale);  }}

// ...import { LocalizedLinkDirective } from "./directives/localized-link.directive";@Component({  selector: "app-root",  standalone: true,  imports: [/*...,*/ LocalizedLinkDirective],  template: ` <a href="/home" appLocalizedLink>Home</a> `,})export class AppComponent {}

import { ApplicationConfig } from "@angular/core";import { provideRouter } from "@angular/router";import { routes } from "./app.routes";import { createIntlayerMarkdownProvider } from "angular-intlayer/markdown";import MarkdownIt from "markdown-it";const md = new MarkdownIt({  html: true,  linkify: true,  typographer: true,});export const appConfig: ApplicationConfig = {  providers: [    provideRouter(routes),    createIntlayerMarkdownProvider((markdown) => md.render(markdown)),  ],};