Lingua

⚠️ Under Development: This package is currently under active development and is not ready for production use.

Share Laravel translations with your Inertia.js + React frontend.

Quick Start

1. Install

composer require tooinfinity/lingua
php artisan lingua:install

This installs the Laravel package, publishes the config, and installs the React package (@tooinfinity/lingua-react).

2. Configure Locales

Edit config/lingua.php:

'locales' => ['en', 'fr', 'es'],

3. Middleware

The middleware is auto-registered to the web group by default. No action needed for most apps.

To disable auto-registration and add manually:

// config/lingua.php
'middleware' => [
    'auto_register' => false,
],

// bootstrap/app.php
->withMiddleware(function (Middleware $middleware) {
    $middleware->web(append: [
        \TooInfinity\Lingua\Http\Middleware\LinguaMiddleware::class,
    ]);
})

4. Create Translations

lang/
├── en/
│   └── messages.php
└── fr/
    └── messages.php

// lang/en/messages.php
return [
    'welcome' => 'Welcome!',
    'greeting' => 'Hello, :name!',
];

// lang/fr/messages.php
return [
    'welcome' => 'Bienvenue!',
    'greeting' => 'Bonjour, :name!',
];

5. Use in React

import { useTranslations } from '@tooinfinity/lingua-react';

function Welcome() {
    const { __, locale, locales } = useTranslations();

    return (
        <div>
            <h1>{__('messages.welcome')}</h1>
            <p>{__('messages.greeting', { name: 'John' })}</p>
            <p>Current: {locale}</p>
        </div>
    );
}

Locale Switching

import { router } from '@inertiajs/react';
import { useTranslations } from '@tooinfinity/lingua-react';

function LocaleSwitcher() {
    const { locale, locales } = useTranslations();

    const switchLocale = (newLocale: string) => {
        router.post('/locale', { locale: newLocale });
    };

    return (
        <div>
            {locales.map((loc) => (
                <button
                    key={loc}
                    onClick={() => switchLocale(loc)}
                    disabled={loc === locale}
                >
                    {loc.toUpperCase()}
                </button>
            ))}
        </div>
    );
}

Translation Groups (Optional)

Load only the translations needed for a specific request by passing group names to the middleware. When no groups are provided, Lingua shares all translations.

Route::middleware(['web', 'lingua:common,validation'])->get('/dashboard', function () {
    // ...
});

You can also load specific groups manually via Lingua::translationsFor(['common', 'validation']).

API Reference

useTranslations() Hook

const { __, locale, locales, direction, isRtl } = useTranslations();

__('messages.welcome')                    // "Welcome!"
__('messages.greeting', { name: 'John' }) // "Hello, John!"

Facade

use TooInfinity\Lingua\Facades\Lingua;

Lingua::getLocale();           // Get current locale
Lingua::setLocale('fr');       // Set locale (optionally persists cookie)
Lingua::supportedLocales();    // Get supported locales
Lingua::translations();        // Get all translations (missing keys fall back to default locale)

Fallback Locale Behavior

When a translation key is missing in the current locale, Lingua automatically fills it from the default locale. This applies to:

• PHP translation groups loaded via Lingua::translationGroup() and Lingua::translations()
• JSON translations loaded via Lingua::translations() when translation_driver is json

If the current locale already matches the default locale, no fallback merge occurs.

// config/lingua.php
'default' => 'en',

// lang/en/auth.php
return [
    'login' => 'Login',
    'logout' => 'Logout',
];

// lang/fr/auth.php
return [
    'login' => 'Connexion',
];

Lingua::setLocale('fr');

// 'logout' comes from the default locale
Lingua::translationGroup('auth');
// ['login' => 'Connexion', 'logout' => 'Logout']

Routes

Note: The route prefix can be configured via config('lingua.routes.prefix').

Translation File Formats

Lingua supports both PHP and JSON translation files. Configure the driver in config/lingua.php:

'translation_driver' => 'php', // or 'json'

PHP Translations (Default)

PHP translations are organized in groups (files) under lang/{locale}/:

lang/
├── en/
│   ├── messages.php
│   └── validation.php
└── fr/
    ├── messages.php
    └── validation.php

// lang/en/messages.php
return [
    'welcome' => 'Welcome!',
    'greeting' => 'Hello, :name!',
];

Shared to React as:

{
  "messages": {
    "welcome": "Welcome!",
    "greeting": "Hello, :name!"
  },
  "validation": { ... }
}

Access in React: __('messages.welcome')

JSON Translations

JSON translations use a flat key-value structure in lang/{locale}.json:

lang/
├── en.json
└── fr.json

// lang/en.json
{
  "Welcome!": "Welcome!",
  "Hello, :name!": "Hello, :name!",
  "auth.login": "Login",
  "auth.logout": "Logout"
}

Shared to React as-is (flat structure):

{
  "Welcome!": "Welcome!",
  "Hello, :name!": "Hello, :name!",
  "auth.login": "Login",
  "auth.logout": "Logout"
}

Access in React: __('Welcome!') or __('auth.login')

Tip: JSON translations are ideal for simple apps or when using Laravel's __() helper with literal string keys.

Advanced

Custom Controller

// config/lingua.php
'controller' => \App\Http\Controllers\LocaleController::class,

namespace App\Http\Controllers;

use Illuminate\Http\Request;
use Illuminate\Validation\Rule;
use TooInfinity\Lingua\Lingua;

class LocaleController
{
    public function __invoke(Request $request, Lingua $lingua)
    {
        $validated = $request->validate([
            'locale' => ['required', 'string', Rule::in($lingua->supportedLocales())],
        ]);

        $lingua->setLocale($validated['locale']);

        return redirect()->route('dashboard');
    }
}

License

MIT License. See LICENSE.md.