Laravel Jetstream Lang Ja Laravel Package

Getting Started

This release (1.0.1) is a Japanese localization pack for Jetstream, Livewire, and Fortify. The first use case is a Laravel app using Jetstream (Livewire stack) and Fortify where you want Japanese validation, authentication, password-reset, and UI strings instead of English defaults.

Minimal steps:

1. Require the package with Composer (use the exact vendor/package from its README):

   composer require <vendor>/<package>
   

2. Publish the language files. The package should expose a publish tag; check its service provider or README:

   php artisan vendor:publish --provider="<Vendor>\<Package>\<PackageServiceProvider>"
   # or, if a tag is documented:
   php artisan vendor:publish --tag=<package-lang>
   

3. Set the application locale to Japanese in config/app.php:

   'locale' => 'ja',
   'fallback_locale' => 'en',
   

4. Clear caches:

   php artisan optimize:clear
   

5. Verify a known key resolves in Japanese:

   php artisan tinker
   >>> __('auth.failed');
   

Where to look first:

• The published lang/ja/ directory (Laravel 9+) or resources/lang/ja/ (older Laravel). Look for auth.php, passwords.php, validation.php, and any Jetstream/Fortify-specific files.
• The package service provider’s publishes() method to see exact source/target paths and tags.
• config/app.php for locale and fallback_locale.
• config/fortify.php and config/jetstream.php if auth features or views are customized.

First practical check: open a Jetstream registration or login page, submit invalid data, and confirm Livewire validation errors and Fortify auth failures appear in Japanese.

Implementation Patterns

Global Japanese application

Set locale => 'ja' when the app is Japanese-only. This is the simplest pattern and covers Livewire validation messages (Livewire delegates validation to Laravel’s validator) and Fortify’s auth/password messages.

Per-user or per-request locale

For multi-language apps, keep locale as a default and switch per request with middleware:

public function handle($request, Closure $next)
{
    app()->setLocale($request->user()?->locale ?? config('app.locale'));

    return $next($request);
}

Place it after session/auth middleware so the user is available.

Publish-then-override

Treat published files as application-owned translations. Publish once, commit lang/ja/ to version control, and edit project-specific wording there. This avoids vendor edits and keeps upgrades predictable. If you need to refresh from a newer package release, republish with --force only after reviewing the diff.

Custom validation attribute names

Japanese validation messages often still show English field names (email, password). Add Japanese attribute names in lang/ja/validation.php:

'attributes' => [
    'name' => '名前',
    'email' => 'メールアドレス',
    'password' => 'パスワード',
],

This is especially visible in Livewire forms and Fortify auth screens.

Fortify integration

Fortify uses Laravel’s auth.php, passwords.php, and validation.php keys for most flows. After publishing, test:

• Failed login (auth.failed)
• Throttled login (auth.throttle)
• Password reset link status (passwords.sent, passwords.user, passwords.throttled, passwords.reset)
• Registration validation errors

If you have customized Fortify views, continue using __('...') so the published Japanese files are used.

Jetstream integration

For the Livewire stack, Jetstream’s Blade views and Livewire components use translation keys. Verify profile update, password update, team management (if enabled), and API token screens. If using the Inertia/Vue stack, check whether the package covers JavaScript-side strings; you may still need to translate frontend JSON/JS language files separately.

Testing pattern

Assert localized output in feature tests:

$this->get('/login')->assertSee('ログイン');
$this->post('/login', [])->assertSessionHasErrors('email');

For Livewire components, use Livewire::test(...)->assertHasErrors(...) and assert the Japanese message where relevant.

Deployment workflow

Commit published language files, run php artisan optimize:clear during deploy, and include a smoke test that resolves a few critical keys (auth.failed, validation.required, passwords.sent). Language files are not config-cached, but stale opcache/view cache can still make changes appear delayed.

Gotchas and Tips

• Locale must actually be ja. Publishing files alone does nothing if config/app.php still has locale => 'en'. Also check fallback_locale: missing Japanese keys will silently fall back to English.
• Laravel version path differences. Laravel 9+ uses the root lang/ directory by default; older versions use resources/lang/. Confirm where the package publishes and where your app loads translations. If they differ, move or reconfigure.
• Livewire does not own validation messages. Livewire uses Laravel’s validator, so Japanese validation comes from lang/ja/validation.php. If messages remain English, check locale and the validation file, not Livewire itself.
• Fortify has some framework-level strings. Most Fortify messages are translation keys, but custom actions, custom views, and hardcoded strings in your own code will not be translated automatically.
• Jetstream frontend strings may be split. Blade/Livewire strings are typically covered by PHP language files. Inertia/Vue stacks may require separate JavaScript translations, and some package UIs may include hardcoded English in vendor views.
• Publishing tags vary. If vendor:publish prompts for a provider, select the package provider. If a tag is documented, prefer the tag to avoid publishing unrelated assets.
• Do not edit vendor files. Always publish and override. Vendor changes are lost on composer update.
• Use --force carefully. Republishing can overwrite your project-specific Japanese wording. Review diffs before forcing.
• Clear caches after changes. Run php artisan optimize:clear. In production, also ensure opcache is refreshed if language files changed.
• Check pluralization and trans_choice. Japanese does not pluralize like English. Some validation or password throttling messages use pluralization; verify the output reads naturally.
• Add Japanese field attributes. Without validation.attributes, users see Japanese messages containing English field names such as email. This is the most common polish issue in Livewire/Fortify forms.
• Debugging missing keys. Use php artisan tinker and __('auth.failed'), __('validation.required'), __('passwords.sent'). Check app()->getLocale() and the loaded translation paths with app('translator')->getLoader()->namespaces() if necessary.
• Version pinning. 1.0.1 is an early release focused on Japanese localization for Jetstream, Livewire, and Fortify. Pin the version in composer.json if you need stability, and review release notes for missing or added keys before upgrading.
• Extension point. Any missing string can be overridden by creating the corresponding file under lang/ja/ in your app. Laravel’s application language files take precedence over vendor package translations for the same group/key.
• Smoke-test after deploy. Verify login failure, registration validation, password reset, and a Livewire form error. These cover the three integrations named in the release.