Symfony：如何在编辑表单中设置文件类型？

Question

当我想用 symfony 编辑表单中的“事件”时出现此错误：

“表单的视图数据应该是“Symfony\Component\HttpFoundation\File\File”，但它是一个“字符串”。您可以通过将“data_class”选项设置为 null 或添加将“字符串”转换为“Symfony\Component\HttpFoundation\File\File”实例的视图转换器。”

我遵循文档并将其添加到我的控制器中：

$event->setEventImage(
            new File($this->getParameter('images_dir').'/'.$event->getEventImage())
        );

但它并没有改变什么，我不明白为什么。

所以有我的实体：

  /**
     *
     * @ORM\Column (type="string")
     * @Assert\NotBlank(message="Merci de charger un fichier au format image.")
     * @Assert\File(mimeTypes={ "image/*" })
     */
    private $eventImage;
  public function getEventImage(): ?string
    {
        return $this->eventImage;
    }

    public function setEventImage(string $eventImage): self
    {
        $this->eventImage = $eventImage;

        return $this;
    }

还有我的控制器：

 #[Route('/{id}/edit', name: 'events_edit', methods: ['GET','POST'])]
    public function edit(Request $request, Events $event, SluggerInterface $slugger): Response
    {

        $event->setEventImage(
            new File($this->getParameter('images_dir').'/'.$event->getEventImage())
        );

        $form = $this->createForm(EventsType::class, $event);

        $form->handleRequest($request);

        if ($form->isSubmitted() && $form->isValid()) {

            /** @var UploadedFile $eventImage */
            $eventImage = $form->get('eventImage')->getData();

            // this condition is needed because the 'eventImage' field is not required
            // so the Image file must be processed only when a file is uploaded
            if ($eventImage) {
                $originalFilename = pathinfo($eventImage->getClientOriginalName(), PATHINFO_FILENAME);
                // this is needed to safely include the file name as part of the URL
                $safeFilename = $slugger->slug($originalFilename);
                $newFilename = $safeFilename . '-' . uniqid() . '.' . $eventImage->guessExtension();

                // Move the file to the directory where images are stored
                try {
                    $eventImage->move(
                        $this->getParameter('images_dir'),
                        $newFilename
                    );
                } catch (FileException $e) {
                    // ... handle exception if something happens during file upload
                }

                // updates the 'eventImage' property to store the image file name
                // instead of its contents
                $event->setEventImage($newFilename);
            }
            $this->getDoctrine()->getManager()->flush();

            return $this->redirectToRoute('events_index', [], Response::HTTP_SEE_OTHER);
        }

        return $this->renderForm('events/edit.html.twig', [
            'event' => $event,
            'form' => $form,
        ]);
    }

还有我的 EventsType ：

public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $builder
            ->add('title')
            ->add('subtitle')

            ->add('content', CKEditorType::class, [
                'label' => 'content',
                'required' => false,
            ])
            ->add('dateEvent', DateTimeType::class, [
                'widget' => 'single_text',
                'label' => 'Date d\'arrivée : '
            ])
            ->add('place')
            ->add('dateDead', DateType::class, [
                'widget' => 'single_text',
                'label' => 'Date limite d\'inscription : '
            ])
            ->add('numberPersonRestricted')
            ->add('eventImage', FileType::class, [
                'label' => 'Image (fichier image)',
                'required' => false,
                'constraints' => [
                    new File([
                        'maxSize' => '1024k',
                        'mimeTypes' => [
                            'image/*',
                        ],
                        'mimeTypesMessage' => 'Please upload a valid image',
                    ])
                ]
            ])
        ;
    }

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

Answer 1

        ->add('eventImage', FileType::class, [
            'label' => 'Image (fichier image)',
            'required' => false,
            'constraints' => [
                new File([
                    'maxSize' => '1024k',
                    'mimeTypes' => [
                        'image/*',
                    ],
                    'mimeTypesMessage' => 'Please upload a valid image',
                ])
            ]
            'data_class' => null
        ])

在您的表单类型中，您可以将参数 'data_class' => null（如上面的示例）添加到 eventImage 将删除警告并在您添加新文件时工作，但如果您不添加新文件进行编辑，它应该保持不变在你的 bd 中为 null。

要克服这个问题，以便能够在文件存在时预填充文件字段，可以执行诸如指向文件位置之类的操作。即保存在数据库中的文件的路径。

所以你正在做的是检查你的视图，看看是否存在数据库中存在的文件路径的文件，然后通过执行类似的操作来预填充它（不要忘记更改你的上传路径):

 {% if form.eventImage.vars.data %} <img src="{{ asset('/uploads/directory/' ~ form.eventImage.vars.data.filename) }}"/>{% endif %}