Symfony中Doctrine MongoDB Bundle的DocumentType字段关联报错排查

问题背景 #

我希望在MongoDB中实现文档间的关联引用，了解到Doctrine MongoDB Bundle提供了DocumentType表单类型，作用类似ORM中的EntityType，但官方文档仅提及该类型存在，未提供示例及详细说明。实现过程中先后遇到两个错误：

第一个错误：

Symfony\Bridge\Doctrine\Form\Type\DoctrineType::getCachedIdReader(): Argument #1 ($manager) must be of type Doctrine\Persistence\ObjectManager, null given, called in /var/www/clim_rep/vendor/symfony/doctrine-bridge/Form/Type/DoctrineType.php on line 199

调整实现方式后出现第二个错误：

"Doctrine MongoDB Manager named 'Doctrine\ODM\MongoDB\DocumentManager' does not exist"

以下是我编写的ReportType类代码：

<?php
/**
 * ReportType - This class is responsible for creating the form for all Reports
 **/
declare(strict_types=1);

namespace App\Form;

use App\Document\Partner;
use App\Document\Report;
use App\Document\State;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\NumberType;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\Extension\Core\Type\DateType;
use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Symfony\Component\Form\FormEvent;
use Symfony\Component\Form\FormEvents;
use Symfony\Component\Form\Event\PreSubmitEvent;
use Doctrine\Bundle\MongoDBBundle\Form\Type\DocumentType;
use Doctrine\ODM\MongoDB\DocumentManager;
use Doctrine\Persistence\ObjectManager;

/**
 * ReportType
 * This class is responsible for creating the form for the rental entity.
 **/
class ReportType extends AbstractType
{
    /**
     * buildForm - This function is responsible for building the form for the rental entity.
     *
     * @param FormBuilderInterface $builder - The form builder interface
     * @param array                $options - The options for the form
     */
    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $today = new \DateTime();
        $builder
            ->add('name', TextType::class)
            ->add('date', TextType::class)
            ->add('author', TextType::class)
            ->add('report_type', TextType::class)
            ->add('description', TextType::class)
            ->add('partners', DocumentType::class, [
                'class' => Partner::class,
                'choice_label' => 'name',
                'expanded' => true,
                'multiple' => true,
                'document_manager' => DocumentManager::class,
            ])
//          ->add('states', DocumentType::class, [
//              'class' => State::class,
//              'choice_label' => 'name',
//              'expanded' => true,
//              'multiple' => true,
//          ])
            ->add('dews_region', TextType::class)
            ->add('climate_region', TextType::class);
    }

    /**
     * configureOptions - This function is responsible for setting the default options for the form.
     *
     * @param OptionsResolver $resolver - The options resolver
     * */
    public function configureOptions(OptionsResolver $resolver): void
    {
        $resolver->setDefaults(
            [
                'data_class' => Report::class,
                'entityManager' => null,
            ]
        );
    }
}

错误原因及修复方案 #

核心问题 #

1. 第一个错误是因为DocumentType未获取到有效的DocumentManager实例，传入了null值。
2. 第二个错误是因为document_manager选项传入了类名（DocumentManager::class），但该选项需要的是DocumentManager实例或配置中定义的管理器名称（字符串，比如默认的default）。

修复步骤 #

1. 移除错误的document_manager配置：
   若仅使用一个MongoDB DocumentManager，无需手动指定该选项，Bundle会自动注入默认管理器。若存在多个管理器，需传入管理器的配置名称（如'document_manager' => 'custom_mongo_manager'），而非类名。

2. 删除多余的entityManager默认配置：
   Form组件会自动处理Doctrine管理器的注入，configureOptions中设置的'entityManager' => null属于冗余配置，应移除。

修正后的代码 #

<?php
/**
 * ReportType - This class is responsible for creating the form for all Reports
 **/
declare(strict_types=1);

namespace App\Form;

use App\Document\Partner;
use App\Document\Report;
use App\Document\State;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;
use Doctrine\Bundle\MongoDBBundle\Form\Type\DocumentType;

/**
 * ReportType
 * This class is responsible for creating the form for the rental entity.
 **/
class ReportType extends AbstractType
{
    /**
     * buildForm - This function is responsible for building the form for the rental entity.
     *
     * @param FormBuilderInterface $builder - The form builder interface
     * @param array                $options - The options for the form
     */
    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $today = new \DateTime();
        $builder
            ->add('name', TextType::class)
            ->add('date', TextType::class)
            ->add('author', TextType::class)
            ->add('report_type', TextType::class)
            ->add('description', TextType::class)
            ->add('partners', DocumentType::class, [
                'class' => Partner::class,
                'choice_label' => 'name',
                'expanded' => true,
                'multiple' => true,
                // 移除错误的document_manager配置
            ])
            ->add('states', DocumentType::class, [
                'class' => State::class,
                'choice_label' => 'name',
                'expanded' => true,
                'multiple' => true,
            ])
            ->add('dews_region', TextType::class)
            ->add('climate_region', TextType::class);
    }

    /**
     * configureOptions - This function is responsible for setting the default options for the form.
     *
     * @param OptionsResolver $resolver - The options resolver
     * */
    public function configureOptions(OptionsResolver $resolver): void
    {
        $resolver->setDefaults(
            [
                'data_class' => Report::class,
                // 移除多余的entityManager配置
            ]
        );
    }
}

内容的提问来源于stack exchange，提问作者Tom Belknap