nette-forms

---

name: nette-forms description: Invoke before creating or modifying Nette Forms. Provides form controls, validation, rendering patterns.

Nette Forms

Nette Forms provides secure, reusable forms with automatic validation on both client and server side.

Copycomposer require nette/forms

Forms in Presenters

Forms are created in factory methods named createComponent<Name>:

Copyprotected function createComponentRegistrationForm(): Form
{
	$form = new Form;
	$form->addText('name', 'Name:')
		->setRequired('Please enter your name.');

	$form->addEmail('email', 'Email:')
		->setRequired('Please enter your email.');

	$form->addPassword('password', 'Password:')
		->setRequired('Please enter password.')
		->addRule($form::MinLength, 'Password must be at least %d characters', 8);

	$form->addSubmit('send', 'Register');

	$form->onSuccess[] = $this->registrationFormSucceeded(...);
	return $form;
}

private function registrationFormSucceeded(Form $form, \stdClass $data): void
{
	// $data->name, $data->email, $data->password
	$this->flashMessage('Registration successful.');
	$this->redirect('Home:');
}

Render in template:

Copy{control registrationForm}

Create and Edit Pattern

Unified form for both creating and editing records:

Copyclass ProductPresenter extends BasePresenter
{
	public function __construct(
		private ProductFacade $facade,
	) {}

	public function renderEdit(int $id = null): void
	{
		$this->template->product = $id
			? $this->facade->getProduct($id)
			: null;
	}

	protected function createComponentProductForm(): Form
	{
		$form = new Form;
		$form->addText('name', 'Name:')
			->setRequired();
		$form->addTextArea('description', 'Description:');
		$form->addInteger('price', 'Price:')
			->setRequired()
			->addRule($form::Min, 'Price must be positive', 1);
		$form->addSubmit('send', 'Save');
		$form->onSuccess[] = $this->productFormSucceeded(...);
		return $form;
	}

	private function productFormSucceeded(Form $form, \stdClass $data): void
	{
		$id = $this->getParameter('id');
		if ($id) {
			$this->facade->update($id, (array) $data);
			$this->flashMessage('Product updated.');
		} else {
			$this->facade->create((array) $data);
			$this->flashMessage('Product created.');
		}
		$this->redirect('default');
	}
}

Template with edit check:

Copy{block content}
<h1>{if $product}Edit: {$product->name}{else}New Product{/if}</h1>

{form productForm}
	{if $product}
		{$form['name']->setDefaultValue($product->name)}
		{$form['description']->setDefaultValue($product->description)}
		{$form['price']->setDefaultValue($product->price)}
	{/if}
	<table>
		<tr>
			<td>{label name}{input name}</td>
		</tr>
		<tr>
			<td>{label description}{input description}</td>
		</tr>
		<tr>
			<td>{label price}{input price}</td>
		</tr>
	</table>
	{input send}
{/form}
{/block}

Form Reuse with Factory

For forms used in multiple places, create a factory:

Copyfinal class ProductFormFactory
{
	public function __construct(
		private FormFactory $formFactory,
	) {}

	public function create(callable $onSuccess): Form
	{
		$form = $this->formFactory->create();
		$form->addText('name', 'Name:')
			->setRequired();
		$form->addTextArea('description', 'Description:');
		$form->addInteger('price', 'Price:')
			->setRequired();
		$form->addSubmit('send');
		$form->onSuccess[] = function (Form $form, \stdClass $data) use ($onSuccess) {
			$onSuccess($data);
		};
		return $form;
	}
}

Use in presenter:

Copypublic function __construct(
	private ProductFormFactory $productFormFactory,
) {}

protected function createComponentProductForm(): Form
{
	return $this->productFormFactory->create(
		function (\stdClass $data): void {
			$this->facade->save($data);
			$this->redirect('default');
		},
	);
}

Common Form Controls

For complete control reference, see controls.md.

Basic Validation

Copy$form->addText('name')
	->setRequired('Name is required.')
	->addRule($form::MinLength, 'At least %d characters', 3)
	->addRule($form::MaxLength, 'Maximum %d characters', 100);

$form->addEmail('email')
	->setRequired()
	->addRule($form::Email, 'Invalid email format.');

$form->addInteger('age')
	->addRule($form::Range, 'Age must be between %d and %d', [18, 120]);

$form->addPassword('password')
	->setRequired()
	->addRule($form::MinLength, 'At least %d characters', 8);

$form->addPassword('password2')
	->setRequired()
	->addRule($form::Equal, 'Passwords must match', $form['password']);

For complete validation reference, see validation.md.

Conditional Validation

Copy$form->addCheckbox('newsletter', 'Subscribe to newsletter');

$form->addEmail('email')
	->addConditionOn($form['newsletter'], $form::Equal, true)
		->setRequired('Email required for newsletter.');

Form Rendering

Default rendering:

Copy{control productForm}

Manual rendering:

Copy{form productForm}
<table>
	<tr>
		<th>{label name /}</th>
		<td>{input name} {inputError name}</td>
	</tr>
	<tr>
		<th>{label email /}</th>
		<td>{input email} {inputError email}</td>
	</tr>
</table>
{input send}
{/form}

With Bootstrap:

Copy{form productForm class => 'form-horizontal'}
<div class="mb-3">
	{label name class => 'form-label' /}
	{input name class => 'form-control'}
	{inputError name class => 'invalid-feedback'}
</div>
{/form}

For complete rendering reference, see rendering.md.

Form Events

Copy// Before rendering (modify form)
$form->onRender[] = function (Form $form): void {
	// Add CSS classes, modify controls
};

// After successful validation
$form->onSuccess[] = function (Form $form, \stdClass $data): void {
	// Process valid data
};

// After any submission (valid or invalid)
$form->onSubmit[] = function (Form $form): void {
	// Logging, analytics
};

// Custom validation after rules pass
$form->onValidate[] = function (Form $form): void {
	if ($this->isBlocked($form->getValues()->email)) {
		$form->addError('This email is blocked.');
	}
};

Error Handling

Copyprivate function productFormSucceeded(Form $form, \stdClass $data): void
{
	try {
		$this->facade->save($data);
		$this->redirect('default');
	} catch (DuplicateEntryException) {
		$form['email']->addError('Email already exists.');
	} catch (\Exception $e) {
		$form->addError('An error occurred.');
	}
}

Anti-Patterns to Avoid

• Don't put business logic in form handlers - use services/facades
• Don't create forms in action methods - use createComponent* factory
• Don't validate twice - use form validation, not manual checking
• Don't skip setRequired() - always validate required fields

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Online Documentation

For detailed information, fetch from doc.nette.org:

• Forms - complete forms guide
• Controls - all form controls
• Validation - validation rules
• Rendering - rendering options