Symfony EntityType 默认值设置：会话数据与托管实体处理指南

use App\Entity\Etude;
use Symfony\Bridge\Doctrine\Form\Type\EntityType;
use Doctrine\ORM\EntityManagerInterface; // 注入或通过服务获取

// 假设 $entityManager 已经被注入到你的 FormType 或 Controller 中
// 假设 $selectedEtude 是一个从数据库中获取的托管 Etude 实体
$builder->add('etude', EntityType::class, [
    'label' => 'Étude',
    'class' => Etude::class,
    'required' => false,
    'data' => $selectedEtude, // 必须是托管实体
]);

// In your Controller
use App\Form\FilterActeType;
use Doctrine\ORM\EntityManagerInterface;
use Symfony\Component\HttpFoundation\Request;
use App\Entity\Etude; // 确保导入 Etude 实体类

class YourController extends AbstractController
{
    public function someAction(Request $request, PaginatorService $paginatorService, EntityManagerInterface $entityManager)
    {
        // ... 获取用户ID和路由
        $usrId = $this->getUser()->getId(); // 假设你有一个获取当前用户的方法
        $route = $request->attributes->get('_route');

        // 获取默认过滤器和会话过滤器
        $filters = array_merge(
            $defaultFilter, // 假设 $defaultFilter 已经定义
            $paginatorService->getFiltersFromSessionByContext($usrId, $route)
        );

        $preselectedEtude = null;
        if (isset($filters['etude']) && $filters['etude'] instanceof Etude) {
            // 从会话中获取的 Etude 实体是分离的，需要重新从数据库加载
            // 确保 Etude 实体有一个 getId() 方法
            $etudeId = $filters['etude']->getId();
            if ($etudeId) {
                // 使用 EntityManager 重新加载托管实体
                $preselectedEtude = $entityManager->getRepository(Etude::class)->find($etudeId);
            }
        }

        // 创建表单，并将托管实体作为选项传递
        $filter_form = $this->createForm(FilterActeType::class, null, [
            'filters' => $filters, // 仍然传递原始过滤器，FormType内部可能需要
            'preselected_etude' => $preselectedEtude, // 传递托管实体
        ]);

        // ... 表单处理和渲染
        if ($filter_form->isSubmitted() && $filter_form->isValid()) {
            // 处理表单数据
        }

        return $this->render('your_template.html.twig', [
            'filter_form' => $filter_form->createView(),
        ]);
    }
}

// In your FormType (e.g., FilterActeType)
namespace App\Form;

use App\Entity\Etude;
use Symfony\Bridge\Doctrine\Form\Type\EntityType;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Contracts\Translation\TranslatorInterface; // 假设需要翻译

class FilterActeType extends AbstractType
{
    private $translator;

    public function __construct(TranslatorInterface $translator)
    {
        $this->translator = $translator;
    }

    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $builder->add('etude', EntityType::class, [
            'label' => $this->translator->trans('Étude'),
            'class' => Etude::class,
            'required' => false,
            'attr' => ['dyn-form-data' => 'cabinet,createur,destinataire'],
            'data' => $options['preselected_etude'], // 使用控制器中加载的托管实体
        ]);
        // ... 其他字段
    }

    public function configureOptions(OptionsResolver $resolver): void
    {
        $resolver->setDefaults([
            // ... 其他默认选项
            'filters' => [], // 定义 filters 选项及其默认值
            'preselected_etude' => null, // 定义 preselected_etude 选项及其默认值
        ]);

        // 确保 preselected_etude 选项可以是 Etude 实体或 null
        $resolver->setAllowedTypes('preselected_etude', [Etude::class, 'null']);
    }

    // 原始的 getDataFromFilters 方法在此场景下不再直接用于 data 选项
    // private function getDataFromFilters(array $options, string $field) { ... }
}

$builder->add('etude', EntityType::class, [
    'label' => 'Étude',
    'class' => Etude::class,
    'required' => false,
    'choice_label' => 'libelle', // 显示给用户的文本
    'choice_value' => 'id',     // 作为 <option> value 的属性
]);

$builder->add('etude', EntityType::class, [
    'label' => 'Étude',
    'class' => Etude::class,
    'required' => false,
    'choice_label' => 'libelle',
    'choice_value' => function (?Etude $etude) {
        return $etude ? $etude->getId() : '';
    },
]);