How to make multi language with filament/spatie-laravel-translatable ?

To create a multi-language admin area in Laravel 9 using filament/spatie-laravel-translatable-plugin, you can follow these steps:

1. Install the filament/spatie-laravel-translatable-plugin package using composer:

composer require filament/spatie-laravel-translatable-plugin

1. Create a model for your translatable entity and use the HasTranslations trait provided by the package:

use Illuminate\Database\Eloquent\Model;
use Spatie\Translatable\HasTranslations;

class Post extends Model
{
    use HasTranslations;

    public $translatable = ['title', 'body'];
}

1. Create a form for your translatable entity using Filament's form builder and add the translatable fields using the translatable method:

use Filament\Forms\Form;
use Filament\Forms\Components\TextInput;
use Spatie\Translatable\HasTranslations;

class PostForm extends Form
{
    public function configure()
    {
        $this
            ->schema([
                TextInput::make('title')
                    ->label(__('Title'))
                    ->translatable(),
                TextInput::make('body')
                    ->label(__('Body'))
                    ->translatable(),
            ]);
    }
}

1. In your controller, retrieve the record you want to edit and pass it to the form:

use App\Models\Post;
use App\Forms\PostForm;

class PostController extends Controller
{
    public function edit(Post $post)
    {
        $form = new PostForm($post);

        return view('posts.edit', compact('form'));
    }
}

1. In your view, render the form using Filament's form component:

<x-filament-form :form="$form" />

1. When the form is submitted, the translatable fields will be automatically saved as JSON in the database. You can retrieve the translated values using the getTranslation method:

$post->getTranslation('title', 'fr');

1. To add custom locale fields to the form, you can use Filament's ComponentGroup component:

use Filament\Forms\Components\ComponentGroup;
use Filament\Forms\Components\TextInput;

class PostForm extends Form
{
    public function configure()
    {
        $this
            ->schema([
                ComponentGroup::make(__('Translations'))
                    ->schema([
                        TextInput::make('title')
                            ->label(__('Title'))
                            ->translatable(),
                        TextInput::make('body')
                            ->label(__('Body'))
                            ->translatable(),
                    ]),
                ComponentGroup::make(__('Custom Fields'))
                    ->schema([
                        TextInput::make('custom_field_1')
                            ->label(__('Custom Field 1')),
                        TextInput::make('custom_field_2')
                            ->label(__('Custom Field 2')),
                    ]),
            ]);
    }
}

1. To save the custom locale fields as JSON along with the translatable fields, you can use the saving event of the model:

use Illuminate\Database\Eloquent\Model;
use Spatie\Translatable\HasTranslations;

class Post extends Model
{
    use HasTranslations;

    public $translatable = ['title', 'body'];

    protected static function boot()
    {
        parent::boot();

        static::saving(function ($model) {
            $translations = [];

            foreach ($model->getTranslatableAttributes() as $attribute) {
                foreach ($model->getTranslations($attribute) as $locale => $value) {
                    $translations[$locale][$attribute] = $value;
                }
            }

            $model->custom_fields = json_encode($translations);
        });
    }
}

This will save the custom locale fields as JSON in the custom_fields column of the database along with the translatable fields.