規格とかのcollection系に項目追加するサンプル

HogeServiceProvider.php

<?php

namespace Plugin\Hoge\ServiceProvider;

use Eccube\Entity\ProductClass;
use Eccube\Event\EccubeEvents;
use Eccube\Event\EventArgs;
use Eccube\Event\TemplateEvent;
use Silex\Application as BaseApplication;
use Silex\ServiceProviderInterface;
use Symfony\Component\Form\AbstractTypeExtension;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\Form\FormEvent;
use Symfony\Component\Form\FormEvents;

class HogeServiceProvider implements ServiceProviderInterface
{
    public function register(BaseApplication $app)
    {
        $app['form.type.extensions'] = $app->share($app->extend('form.type.extensions', function ($extensions) use ($app) {
            $extensions[] = new ProductClassHogeExtension();

            return $extensions;
        }));

        $app['eccube.event.dispatcher']->addListener(EccubeEvents::ADMIN_PRODUCT_PRODUCT_CLASS_INDEX_CLASSES, function (EventArgs $event) {
            // ここではとくになにもしない
            $builder = $event->getArgument('builder');
        });

        //
        $app['eccube.event.dispatcher']->addListener('Admin/Product/product_class.twig', function (TemplateEvent $event) {
            $source = $event->getSource();

            $search = '<th id="result_box__header_class_category1';
            $replace = '<th>ほげ</th>'.$search;
            $source = str_replace($search, $replace, $source);

            $search = '<td id="result_box__class_category1';
            $replace = '<td>
                            {{ form_widget(product_class_form.koumoku) }}
                            {{ form_errors(product_class_form.koumoku) }}
                        </td>'.$search;
            $source = str_replace($search, $replace, $source);

            $event->setSource($source);
        });
    }

    public function boot(BaseApplication $app)
    {
    }
}

class ProductClassHogeExtension extends AbstractTypeExtension
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder->add('koumoku', 'text', array(
            'required' => false,
            'mapped' => false,
        ));

        $builder->addEventListener(FormEvents::POST_SET_DATA, function (FormEvent $event) {
            /** @var ProductClass $data */
            $data = $event->getData();
            if (is_null($data)) {
                return;
            }

            if ($data->getId()) {
                // product classに紐づくデータ取得
                // $app['repository']->find($date->getId())

                $form = $event->getForm();
                // 紐付いているデータをセットする
                $form['koumoku']->setData('ほげほげ');
            }
        });
    }

    public function getExtendedType()
    {
        return 'admin_product_class';
    }
}