Forms Laravel Package

Getting Started

Minimal Setup

1. Installation:

   composer require nette/forms
   

   For Laravel integration (standalone), add to composer.json:

   "require": {
       "nette/forms": "^3.2"
   }
   

2. Basic Form Creation:

   use Nette\Forms\Form;
   use Nette\Forms\Controls\TextInput;
   
   $form = new Form();
   $form->addText('username', 'Username:')
        ->addRule(Form::MIN_LENGTH, 'Too short', 3)
        ->addSubmit('send', 'Send');
   
   // Handle submission
   $form->onSuccess[] = function ($form) {
       $values = $form->getValues();
       // Process $values['username']
   };
   

3. Rendering in Blade:

   echo $form->render();
   

   Or use Latte (if integrated) with {formPrint $form}.

First Use Case

Create a login form with validation:

$form = new Form();
$form->addText('email', 'Email')
     ->addRule(Form::EMAIL, 'Invalid email')
     ->addPassword('password', 'Password')
     ->addRule(Form::MIN_LENGTH, 'Too short', 6)
     ->addSubmit('login', 'Login');

$form->onSuccess[] = function ($form) {
    $email = $form->getValue('email');
    // Authenticate user
};

Implementation Patterns

Core Workflows

1. Form Initialization & Submission:

   // In Laravel controller
   public function create(Form $formFactory) {
       $form = $formFactory->create();
       // Add controls, rules, etc.
       return view('form.view', ['form' => $form]);
   }
   
   public function handle(Form $formFactory, Request $request) {
       $form = $formFactory->get($request->get('form_id'));
       if ($form->isSubmitted() && $form->isValid()) {
           $values = $form->getValues();
           // Process
       }
       return redirect()->back();
   }
   

2. Dynamic Forms (Laravel + DI):

   // Register in `services.php`
   $container->addService('formFactory', function () {
       return new Nette\Forms\Container();
   });
   
   // Usage
   $form = $container->get('formFactory');
   $form->addText('dynamic_field')->addRule(Form::FILLED);
   

3. Validation Rules:

   // Built-in rules
   $form->addText('age')->addRule(Form::INTEGER, 'Must be integer')
        ->addRule([$form, 'validateAge'], 'Too young');
   
   // Custom validator
   public function validateAge($value, Form $form) {
       return $value >= 18 || $form->addError('Must be 18+');
   }
   

4. Client-Side Validation:

   // Auto-generated via `netteForms.js`
   $form->addText('name')->addRule(Form::MIN_LENGTH, 'Too short', 2);
   // Renders with `data-nette-rules="minLength:2"`
   

5. File Uploads:

   $form->addUpload('avatar')
        ->addRule(Form::MAX_FILE_SIZE, 'Too large', 5 * 1024 * 1024)
        ->addRule(Form::IMAGE, 'Must be image');
   

Integration Tips

• Laravel Blade: Use {{ $form->render() }} or extract controls:

  @foreach ($form->getControls() as $control)
      <div>{{ $control->getLabel() }}</div>
      {{ $control->getControl()->render() }}
  @endforeach
  

• Latte Integration: Replace Blade with Latte templates for {formPrint $form}.
• CSRF Protection: Enabled by default (uses SameSite cookies).
• Error Handling:

  if (!$form->isValid()) {
      foreach ($form->getErrors() as $error) {
          echo $error->getMessage();
      }
  }
  

Gotchas and Tips

Pitfalls

1. Validation Scope:

   • getValues() returns only validated controls by default. Use:

     $form->getValues(true); // All values (including invalid)
     

   • BC Break: getValues() in v3.2+ respects setValidationScope().

2. Latte Dependency:

   • Some features (e.g., {formPrint}) require Latte. For Blade-only apps:

     use Nette\Forms\Rendering\DefaultFormRenderer;
     $renderer = new DefaultFormRenderer();
     echo $renderer->render($form);
     

3. Client-Side Rules:

   • Only controls with data-nette-rules are validated client-side. Explicitly add rules:

     $form->addText('field')->addRule(Form::FILLED)->setHtmlAttribute('data-nette-rules', 'filled');
     

4. Enum Support:

   • Use addEnum() with BackedEnum:

     enum Status { ACTIVE, INACTIVE }
     $form->addEnum('status', Status::class);
     

5. Hidden Fields:

   • addHidden() accepts any type (unlike setDefaultValue):

     $form->addHidden('user_id')->setValue($user->id);
     

Debugging Tips

1. Validation Errors:

   • Check $form->getErrors() for form-level errors and $control->getErrors() for field-specific issues.
   • Use addRule(Form::CUSTOM, 'Custom message') for granular control.

2. CSRF Issues:

   • Ensure SameSite cookies are supported (PHP 8.1+). For older PHP:

     $form->setHtmlAttribute('data-nette-csrf', true);
     

3. File Uploads:

   • Validate upload_max_filesize in PHP.ini and use:

     $form->addUpload('file')->addRule(Form::MAX_FILE_SIZE, null, 10 * 1024 * 1024);
     

4. Type Safety:

   • Leverage PHP 8.1+ native types:

     $form->addText('age')->addRule(Form::INTEGER)->setType('int');
     

Extension Points

1. Custom Validators:

   class CustomValidator extends Nette\Forms\Validator {
       public function validate($value, Form $form) {
           return $value === 'secret' || $form->addError('Invalid');
       }
   }
   $form->addText('secret')->addRule(new CustomValidator());
   

2. Override Rendering:

   $renderer = new DefaultFormRenderer();
   $renderer->setElementPrototype('div', '<div class="form-group">%html%</div>');
   echo $renderer->render($form);
   

3. Dynamic Controls:

   $form->addDynamic('dynamic_field')
        ->addRule(Form::FILLED)
        ->onValidate[] = function ($control, $value) {
            if (empty($value)) {
                $control->addError('Required');
            }
        };
   

4. Laravel Service Provider:

   // app/Providers/NetteFormsServiceProvider.php
   public function register() {
       $this->app->singleton('form.factory', function () {
           return new Nette\Forms\Container();
       });
   }
   

5. Blueprint Generation:

   • Use Blueprint for DTOs:

     use Nette\Forms\Blueprint;
     $blueprint = new Blueprint($form);
     $blueprint->generate('UserDto.php');