Filament Form with Tabs: Add Relation Managers as Tabs

You can merge relation managers with a form. But if your form has tabs, you can merge relation managers into a form tab. Let me show you how.

First, a basic form with a tab layout.

public static function form(Form $form): Form
    {
        return $form
            ->schema([
                Tabs::make('Tabs')
                    ->columnSpanFull()
                    ->tabs([
                        Tabs\Tab::make('Customer')
                            ->schema([
                                Forms\Components\TextInput::make('name')
                                    ->columnSpanFull(),
                                Forms\Components\TextInput::make('email')
                                    ->email()
                                    ->columnSpanFull(),
                            ]),
                    ]),
            ])->inlineLabel();
    }

Now, we have one tab for the customer information.

Next, we can add a relation manager to every other tab. To do that, we can insert a Livewire component into the form. As a Livewire component, we will call the relation manager.

When inserting a Relation Manager, we must pass ownerRecord and pageClass as parameters.

public static function form(Form $form): Form
{
    return $form
        ->schema([
            Tabs::make('Tabs')
                ->columnSpanFull()
                ->tabs([
                    Tabs\Tab::make('Customer')
                        ->schema([
                            Forms\Components\TextInput::make('name')
                                ->columnSpanFull(),
                            Forms\Components\TextInput::make('email')
                                ->email()
                                ->columnSpanFull(),
                        ]),
                    Tabs\Tab::make('Orders') 
                        ->schema([
                            Forms\Components\Livewire::make(RelationManagers\OrdersRelationManager::class, fn (Page $livewire, Customer $record) => [
                                'ownerRecord' => $record,
                                'pageClass' => $livewire::class,
                            ]),
                        ]), 
                ]),
        ])->inlineLabel();
    }

And that's it; we can see a relation manager in the tab.

With this approach, you will have a problem if your resource can create records. A simple fix is to add visibleOn('edit') for every tab.

Tabs\Tab::make('Orders')
    ->visibleOn('edit') 
    ->schema([
        Forms\Components\Livewire::make(RelationManagers\OrdersRelationManager::class, fn (Page $livewire, Customer $record) => [
            'ownerRecord' => $record,
            'pageClass' => $livewire::class,
        ]),
    ]),

The original solution is from Leandro Ferreira on Discord.