FormServiceProvider

The FormServiceProvider provides a service for building forms in your application with the Symfony2 Form component.

Parameters

• form.secret: This secret value is used for generating and validating the CSRF token for a specific page. It is very important for you to set this value to a static randomly generated value, to prevent hijacking of your forms. Defaults to md5(__DIR__).

Services

• form.factory: An instance of FormFactory, that is used for build a form.
• form.csrf_provider: An instance of an implementation of the CsrfProviderInterface, defaults to a DefaultCsrfProvider.

Registering

use Silex\Provider\FormServiceProvider;

$app->register(new FormServiceProvider());

Note

If you don’t want to create your own form layout, it’s fine: a default one will be used. But you will have to register the translation provider as the default form layout requires it.

If you want to use validation with forms, do not forget to register the Validator provider.

Note

The Symfony Form Component and all its dependencies (optional or not) comes with the “fat” Silex archive but not with the regular one.

If you are using Composer, add it as a dependency to your composer.json file:

"require": {
    "symfony/form": "2.1.*"
}

If you are going to use the validation extension with forms, you must also add a dependency to the symfony/config and `symfony/translation components:

"require": {
    "symfony/validator": "2.1.*",
    "symfony/config": "2.1.*",
    "symfony/translation": "2.1.*"
}

The Symfony Form Component relies on the PHP intl extension. If you don’t have it, you can install the Symfony Locale Component as a replacement:

"require": {
    "symfony/locale": "2.1.*"
}

If you want to use forms in your Twig templates, make sure to install the Symfony Twig Bridge:

"require": {
    "symfony/twig-bridge": "2.1.*"
}

Usage

The FormServiceProvider provides a form.factory service. Here is a usage example:

$app->match('/form', function (Request $request) use ($app) {
    // some default data for when the form is displayed the first time
    $data = array(
        'name' => 'Your name',
        'email' => 'Your email',
    );

    $form = $app['form.factory']->createBuilder('form', $data)
        ->add('name')
        ->add('email')
        ->add('gender', 'choice', array(
            'choices' => array(1 => 'male', 2 => 'female'),
            'expanded' => true,
        ))
        ->getForm();

    if ('POST' == $request->getMethod()) {
        $form->bind($request);

        if ($form->isValid()) {
            $data = $form->getData();

            // do something with the data

            // redirect somewhere
            return $app->redirect('...');
        }
    }

    // display the form
    return $app['twig']->render('index.twig', array('form' => $form->createView()));
});

And here is the index.twig form template (requires symfony/twig- bridge):

<form action="#" method="post">
    {{ form_widget(form) }}

    <input type="submit" name="submit" />
</form>

If you are using the validator provider, you can also add validation to your form by adding constraints on the fields:

use Symfony\Component\Validator\Constraints as Assert;

$app->register(new Silex\Provider\ValidatorServiceProvider());
$app->register(new Silex\Provider\TranslationServiceProvider(), array(
    'translator.messages' => array(),
));

$form = $app['form.factory']->createBuilder('form')
    ->add('name', 'text', array(
        'constraints' => array(new Assert\NotBlank(), new Assert\MinLength(5))
    ))
    ->add('email', 'text', array(
        'constraints' => new Assert\Email()
    ))
    ->add('gender', 'choice', array(
        'choices' => array(1 => 'male', 2 => 'female'),
        'expanded' => true,
        'constraints' => new Assert\Choice(array(1, 2)),
    ))
    ->getForm();

You can register form extensions by extending form.extensions:

$app['form.extensions'] = $app->share($app->extend('form.extensions', function ($extensions) use ($app) {
    $extensions[] = new YourTopFormExtension();

    return $extensions;
}));

Traits

Silex\Application\FormTrait adds the following shortcuts:

• form: Creates a FormBuilder instance.

$app->form($data);

For more information, consult the Symfony2 Forms documentation.