Как исправить ошибку «но новое значение должно быть массивом или экземпляром \ Traversable» в Symfony

Question

Я создаю приложение для управления багажом и рейсами с Symfony 4, я создал отношение " ManyToMany " между этими объектами.

Когда я хочу добавить новый багаж с пунктом назначения(путешествие) У меня есть эта ошибка:

У меня addVoyage и removeVoyage в моих классах Voyage и Bagage.

Вы найдете над моими классами Bagage.php , мою форму BagageType.php и мой контроллер BagageController.php

Bagage.php

<?php

namespace App\Entity;

use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;

/**
 * @ORM\Entity(repositoryClass="App\Repository\BagageRepository")
 */
class Bagage
{
    /**
     * @ORM\Id()
     * @ORM\GeneratedValue()
     * @ORM\Column(type="integer")
     */
    private $id;

    /**
     * @ORM\Column(type="string")
     * @Assert\Length(min=5, max=50)
     */
    private $nom;

    /**
     * @ORM\Column(type="json", nullable=true)
     */
    private $objets = [];

    /**
     * @ORM\Column(type="datetime")
     */
    private $dateCreation;

    /**
     * @ORM\ManyToMany(targetEntity="App\Entity\Voyage", mappedBy="bagages")
     */
    private $voyages;

    public function __construct()
    {
        $this->voyages = new ArrayCollection();
    }

    public function getId(): ?int
    {
        return $this->id;
    }

    public function getNom(): ?string
    {
        return $this->nom;
    }

    public function setNom(string $nom): self
    {
        $this->nom = $nom;

        return $this;
    }

    public function getObjets(): ?array
    {
        return $this->objets;
    }

    public function setObjets(?array $objets): self
    {
        $this->objets = $objets;

        return $this;
    }

    public function getDateCreation(): ?\DateTimeInterface
    {
        return $this->dateCreation;
    }

    public function setDateCreation(\DateTimeInterface $dateCreation): self
    {
        $this->dateCreation = $dateCreation;

        return $this;
    }

    /**
     * @return Collection|Voyage[]
     */
    public function getVoyages(): Collection
    {
        return $this->voyages;
    }

    public function addVoyage(Voyage $voyage): self
    {
        if (!$this->voyages->contains($voyage)) {
            $this->voyages[] = $voyage;
            $voyage->addBagage($this);
        }

        return $this;
    }

    public function removeVoyage(Voyage $voyage): self
    {
        if ($this->voyages->contains($voyage)) {
            $this->voyages->removeElement($voyage);
            $voyage->removeBagage($this);
        }

        return $this;
    }

}
?>

BagageType.php

<?php

namespace App\Form;

use App\Entity\Voyage;
use App\Entity\Bagage;
use Symfony\Bridge\Doctrine\Form\Type\EntityType;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;

class BagageType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('nom')
            ->add('voyages', EntityType::class, [
                'class' => Voyage::class,
                'choice_label' => 'lieu'
            ]);
    }

    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults([
            'data_class' => Bagage::class,
        ]);
    }
}
?>

BagageController.php

<?php
/**
     * @Route("/bagages/nouveau", name="bagage_creation")
     * @Route("/bagages/{id}/edit", name="bagage_edit")
     */
    public function form(Bagage $bagage = null, Request $request, ObjectManager $manager)
    {
        if(!$bagage){
            $bagage = new Bagage();
        }

        $form = $this->createForm(BagageType::class, $bagage);

        $form->handleRequest($request);

        if($form->isSubmitted() && $form->isValid()) {
            if(!$bagage->getId()){
                $bagage->setDateCreation(new \Datetime());
            }

            $manager->persist($bagage);
            $manager->flush();

            return $this->redirectToRoute('bagage_show', [
                'id' => $bagage->getId()
            ]);
        }

        return $this->render('bagages/create.html.twig', [
            //creation d'une vue pour twig pour afficher le formulaire
            'formBagage' => $form->createView(),
            'editMode' => $bagage->getId() !== null
        ]);
    }
?>

Не пропущен ли вызов addVoyage в моем контроллере?

EDIT

Voyage.php

<?php

namespace App\Entity;

use Doctrine\Common\Collections\ArrayCollection;
use Doctrine\Common\Collections\Collection;
use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;

/**
 * @ORM\Entity(repositoryClass="App\Repository\VoyageRepository")
 */
class Voyage
{
    /**
     * @ORM\Id()
     * @ORM\GeneratedValue()
     * @ORM\Column(type="integer")
     */
    private $id;

    /**
     * @ORM\Column(type="string", length=255)
     */
    private $lieu;

    /**
     * @ORM\ManyToMany(targetEntity="App\Entity\Bagage", inversedBy="voyages")
     */
    private $bagages;

    public function __construct()
    {
        $this->bagages = new ArrayCollection();
    }

    public function getId(): ?int
    {
        return $this->id;
    }

    public function getLieu(): ?string
    {
        return $this->lieu;
    }

    public function setLieu(string $lieu): self
    {
        $this->lieu = $lieu;

        return $this;
    }

    /**
     * @return Collection|Bagage[]
     */
    public function getBagages(): Collection
    {
        return $this->bagages;
    }

    public function addBagage(Bagage $bagage): self
    {
        if (!$this->bagages->contains($bagage)) {
            $this->bagages[] = $bagage;
        }

        return $this;
    }

    public function removeBagage(Bagage $bagage): self
    {
        if ($this->bagages->contains($bagage)) {
            $this->bagages->removeElement($bagage);
        }

        return $this;
    }
}

Answer 1

Похоже, вы должны установить атрибут multiple в значение true, делая значение поля массивом, а не одной сущностью.

        ->add('voyages', EntityType::class, [
            'class' => Voyage::class,
            'choice_label' => 'lieu',
            'multiple' => true,
        ]);