Filamentphp - Builder

Question

i have a problem with Builder https://filamentphp.com/docs/2.x/forms/fields#builder it don't save data in json columns.

I have a model Post:

protected $casts = [
        'audio' => 'json',
        'audio_title' => 'json',
    ];

    protected $fillable = [
        'audio_title',
        'audio',
    ];

My migration

Schema::table('posts', function (Blueprint $table) {
            $table->json('audio_title')->nullable();
            $table->json('audio')->nullable();
        });

Builder code

\Filament\Forms\Components\Builder::make('Content')
     ->blocks([
\Filament\Forms\Components\Builder\Block::make('Audio')
                            ->schema([
                                TextInput::make('audio_title'),
                                FileUpload::make('audio')
                                ->directory('audio'),
                            ]),
                        ]),

When i save without Builder, it work

TextInput::make('audio_title'),
FileUpload::make('audio')
>directory('audio'),

What am I doing wrong? Thank you for help!

UPD.

the filament don't encoding data in json automatically. You should to get data in method, and encode their. If you create record, use mutateFormDataBeforeCreate in Filament->resource->NameResource->Pages->CreateName.php

protected function mutateFormDataBeforeCreate(array $data): array
{

    $data['content'] = json_encode($data['block']);
    
    return $data;
}

If you edit record Filament->resource->NameResource->Pages->EditName.php

protected function mutateFormDataBeforeSave(array $data): array
{
    $data['content'] = json_encode($data['block']);
    return $data;
}

protected function mutateFormDataBeforeFill(array $data): array
{

    $data['block'] = json_decode($data['content'], true);
    return $data;
}