Symfony 2 forms+validator demonstration.php

<?php

use Symfony\Components\Form\Form;
use Symfony\Components\Form\FieldGroup;
use Symfony\Components\Form\ChoiceField;
use Symfony\Components\Form\TextField;
use Symfony\Components\Form\CheckboxField;
use Symfony\Components\Form\NumberField;
use Symfony\Components\Form\PasswordField;
use Symfony\Components\Form\DoubleTextField;
use Symfony\Components\Validator\Validator;
use Symfony\Components\Validator\ConstraintValidatorFactory;
use Symfony\Components\Validator\Constraints\Min;
use Symfony\Components\Validator\Constraints\Max;
use Symfony\Components\Validator\Constraints\MinLength;
use Symfony\Components\Validator\Constraints\MaxLength;
use Symfony\Components\Validator\Constraints\AssertType;
use Symfony\Components\Validator\Constraints\Email;
use Symfony\Components\Validator\Constraints\Choice;
use Symfony\Components\Validator\Constraints\Valid;
use Symfony\Components\Validator\Mapping\ClassMetadataFactory;
use Symfony\Components\Validator\Mapping\ClassMetadata;
use Symfony\Components\Validator\Mapping\Loader\LoaderChain;
use Symfony\Components\Validator\Mapping\Loader\StaticMethodLoader;
use Symfony\Components\Validator\Mapping\Loader\XmlFileLoader;
use Symfony\Components\Validator\MessageInterpolator\XliffMessageInterpolator;
use Symfony\Foundation\UniversalClassLoader;

// path pointing to Symfony 2
define('SYMFONY_DIR', __DIR__);

require_once SYMFONY_DIR.'/src/Symfony/Foundation/UniversalClassLoader.php';


class User
{
  public $firstName;
  public $lastName;
  public $email;
  public $married = false;
  public $age = 3;
  public $gender = 'male';
  public $address;

  public static function loadValidatorMetadata(ClassMetadata $metadata)
  {
    $metadata->addPropertyConstraint('firstName', new MinLength(2));
    $metadata->addPropertyConstraint('lastName', new MinLength(2));
    $metadata->addPropertyConstraint('email', new Email());
    $metadata->addPropertyConstraint('age', new Min(6));
    $metadata->addPropertyConstraint('gender', new Choice(array('choices' => self::getGenders())));
    $metadata->addPropertyConstraint('address', new Valid());
  }

  public static function getGenders()
  {
    return array('male', 'female');
  }
}

class Address
{
  public $street;
  public $zipCode;
  public $city;

  public static function loadValidatorMetadata(ClassMetadata $metadata)
  {
    $metadata->addPropertyConstraint('street', new MinLength(6));
    $metadata->addPropertyConstraint('zipCode', new MinLength(4));
    $metadata->addPropertyConstraint('zipCode', new MaxLength(5));
    $metadata->addPropertyConstraint('zipCode', new AssertType('numeric'));
    $metadata->addPropertyConstraint('city', new MinLength(3));
  }
}

class UserAdmin
{
  public $user;
  public $hasAddress;
  public $address;

  public static function loadValidatorMetadata(ClassMetadata $metadata)
  {
    $metadata->addPropertyConstraint('user', new Valid());
    $metadata->addPropertyConstraint('address', new Valid());
  }

  public function __construct(User $user)
  {
    $this->user = $user;
    $this->hasAddress = ($this->user->address !== null);
    $this->address = $this->hasAddress ? $this->user->address : new Address();
  }
  
  public function persist()
  {
    $this->user->address = $this->hasAddress ? $this->address : null;

    // etc
    var_dump($this->user);
  }
}


\Locale::setDefault('de_AT');

// initialize autoloader
$loader = new UniversalClassLoader();
$loader->registerNamespace('Symfony', SYMFONY_DIR.'/src');
$loader->register();

// initialize validator
$metadataFactory = new ClassMetadataFactory(new LoaderChain(array(
  new StaticMethodLoader('loadValidatorMetadata'),
  new XmlFileLoader(SYMFONY_DIR.'/src/Symfony/Components/Form/Resources/config/validation.xml'),
)));
$validatorFactory = new ConstraintValidatorFactory();
$messageInterpolator = new XliffMessageInterpolator(SYMFONY_DIR.'/src/Symfony/Components/Validator/Resources/i18n/messages.en.xml');
$validator = new Validator($metadataFactory, $validatorFactory, $messageInterpolator);

// Note: the above code will be taken care of by the Symfony 2 core

// create new business object
$user = new User();
$userAdmin = new UserAdmin($user);

// create form to interact with the business object
$form = new Form('admin', $userAdmin, $validator);

$userGroup = new FieldGroup('user');
$userGroup->add(new TextField('firstName'));
$userGroup->add(new TextField('lastName'));
$userGroup->add(new DoubleTextField('email'));
$userGroup->add(new CheckboxField('married'));
$userGroup->add(new NumberField('age'));
$userGroup->add(new ChoiceField('gender', array('choices' => array_combine(User::getGenders(), User::getGenders()))));

$addressGroup = new FieldGroup('address');
$addressGroup->add(new TextField('street'));
$addressGroup->add(new TextField('zipCode'));
$addressGroup->add(new TextField('city'));

$form->add($userGroup);
$form->add(new CheckboxField('hasAddress'));
$form->add($addressGroup);

// bind POST data to the form
if (isset($_POST['admin']))
{
  $form->bind($_POST['admin']);

  if ($form->isValid())
  {
    $userAdmin->persist();
  }
}

?>

<form action="#" method="post">
  <?php echo $form->renderErrors() ?>
  <?php echo $form->render() ?>
  <input type="submit" value="Submit" />
</form>

The validator will most probably be created by the DIC and injected into the controller. When creating a form, you can thus simply refer to the controller property.

I will have a look at your project. Let me know if you find any more limitations or bugs.