Symfony FieldsetType using anonymous functions instead of arrays

README.md

Inspired by: https://github.com/adamquaile/AdamQuaileFieldsetBundle.

This example is using an anonymous function instead of an array to pass the sub types to the FieldsetType from your FormBuilder.

ExampleFormType.php

<?php

namespace Acme\DemoBundle\Form\Type;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Component\Validator\Constraints as Assert;

class ExampleFormType extends AbstractType
{
    /**
     * @param FormBuilderInterface $builder
     * @param array $options
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('testFieldset', 'fieldset', [
            'legend' => 'Test Fieldset!',
            'types' => function(FormBuilderInterface $builder) {
                $builder->add('testField', 'text', [
                    'label' => 'A test field in the fieldset'
                    'attr' => [
                        'class' => 'another-test-class',
                    ],
                ]);
            }
        ]);
    }

    /**
     * @param OptionsResolver $resolver
     */
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([
            'attr' => [
                'novalidate' => 'novalidate',
                'id' => 'form-example-form',
            ],
        ]);
    }

    /**
     * @return string
     */
    public function getName()
    {
        return 'example';
    }
}

FieldsetType.php

<?php

namespace Acme\DemoBundle\Form\Type;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\FormInterface;
use Symfony\Component\Form\FormView;
use Symfony\Component\OptionsResolver\OptionsResolver;

class FieldsetType extends AbstractType
{
    /**
     * @param FormBuilderInterface $builder
     * @param array $options
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        // execute the callable with our FormBuilder passed as an argument
        $options['types']($builder);
    }

    /**
     * @param FormView $view
     * @param FormInterface $form
     * @param array $options
     */
    public function buildView(FormView $view, FormInterface $form, array $options)
    {
        if (false !== $options['legend']) {
            $view->vars['legend'] = $options['legend'];
        }
    }

    /**
     * @param OptionsResolver $resolver
     */
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([
            'legend' => false,
            'virtual' => true,
            'types' => null,
        ])
        ->setAllowedTypes([
            'types' => 'callable',
        ])
        ->setRequired([
            'types',
        ]);
    }

    /**
     * @return string
     */
    public function getName()
    {
        return 'fieldset';
    }
}