Filament: Invoice Editor with Items

The main logic lives in our InvoiceResource and is mainly contained within the form() method:

• Using a Repeater field to allow adding multiple items
• Using the live() method to calculate the subtotal and total in real time
• Using a custom function to trigger calculations on items list change, quantity change
• Disabling options in real-time to prevent duplicate items from being added

Here's how it looks in the code:

app/Filament/Resources/InvoiceResource.php

// ...
 
class InvoiceResource extends Resource
{
    public static function form(Form $form): Form
    {
        $products = Product::get();
 
        return $form
            ->schema([
                Forms\Components\TextInput::make('customer_name')
                    ->required()
                    ->maxLength(255),
                Forms\Components\TextInput::make('customer_email')
                    ->email()
                    ->required()
                    ->maxLength(255),
                Section::make()
                    ->columns(1)
                    ->schema([
                        // Repeatable field for invoice items
                        Forms\Components\Repeater::make('invoiceProducts')
 
                        // ...