Symfony3 不会将文件转换为 UploadedFile答案

【问题标题】：Symfony3 wont convert file to UploadedFileSymfony3 不会将文件转换为 UploadedFile
【发布时间】：2017-02-06 23:48:19
【问题描述】：

我正在关注本教程http://symfony.com/doc/current/controller/upload_file.html，但 $file 没有被转换为 UploadedFile，它仍然是一个字符串：

var_dump($file);
/home/owner/Desktop/Workspace/Documentary/src/DW/DocumentaryBundle/Controller/Admin/DocumentaryController.php:103:string '/tmp/phpmmv1LP' (length=14)

类型错误：传递给 DW\DocumentaryBundle\Uploader\PosterUploader::upload() 的参数 1 必须是 Symfony\Component\HttpFoundation\File\UploadedFile 的实例，给定字符串，在 /home/owner/Desktop/Workspace 中调用/DocumentaryWIRE/src/DW/DocumentaryBundle/Controller/Admin/DocumentaryController.php 第 106 行

创建动作：

     /**
     * @param Request $request
     * @return Response
     */
    public function createAction(Request $request)
    {
        $documentary = new Documentary();

        $form = $this->createForm(DocumentaryType::class, $documentary);
        $form->handleRequest($request);

        if ($form->isSubmitted() && $form->isValid()) {
            $file = $documentary->getPoster();

            $posterUploader = $this->getPosterUploader();
            $fileName = $posterUploader->upload($file);

            $documentary->setPoster($fileName);

            $documentaryService = $this->getDocumentaryService();
            $documentaryService->save($documentary);
        }

        return $this->render('DocumentaryBundle:Admin:create.html.twig', array(
            'form' => $form->createView(),
        ));
    }

查看

{{ form_start(form) }}
{{ form_widget(form) }}
{{ form_end(form) }}

表格：

<?php

namespace DW\DocumentaryBundle\Form;

use DW\DocumentaryBundle\Entity\Documentary;
use Symfony\Bridge\Doctrine\Form\Type\EntityType;
use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\Extension\Core\Type\FileType;
use Symfony\Component\Form\Extension\Core\Type\IntegerType;
use Symfony\Component\Form\Extension\Core\Type\SubmitType;
use Symfony\Component\Form\Extension\Core\Type\TextareaType;
use Symfony\Component\Form\Extension\Core\Type\TextType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolver;

class DocumentaryType extends AbstractType
{
    /**
     * @param FormBuilderInterface $builder
     * @param array $options
     */
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('title', TextType::class)
            ->add('storyline', TextareaType::class)
            ->add('summary', TextareaType::class)
            ->add('year', IntegerType::class)
            ->add('length', IntegerType::class)
            ->add('status', TextType::class)
            ->add('views', IntegerType::class)
            ->add('shortUrl', TextType::class)
            ->add('videoId', TextType::class)
            ->add('videoSource', TextType::class)
            ->add('poster', FileType::class, [
                'label' => 'Poster'])
            ->add('category', EntityType::class, [
                'class' => 'CategoryBundle:Category',
                'choice_label' => 'name',
            ])
            ->add('submit', SubmitType::class);
    }

    /**
     * @param OptionsResolver $resolver
     */
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => Documentary::class,
        ));
    }

    /**
     * @return string
     */
    public function getName()
    {
        return "documentary";
    }
}

控制器：

<?php

namespace DW\DocumentaryBundle\Uploader;

use Symfony\Component\HttpFoundation\File\UploadedFile;

class PosterUploader
{
    /**
     * @var string
     */
    private $targetDir;

    /**
     * @param string $targetDir
     */
    public function __construct(string $targetDir)
    {
        $this->targetDir = $targetDir;
    }

    /**
     * @param UploadedFile $file
     * @return string
     */
    public function upload(UploadedFile $file)
    {
        $fileName = md5(uniqid()).'.'.$file->guessExtension();

        $file->move($this->targetDir, $fileName);

        return $fileName;
    }
}

【问题讨论】：

看看this answer和你的比较，看看差异（如果有的话），并相应地修改。
显然，Documentary 类的 getPosterUploader() 方法返回一个字符串。你能显示它的代码吗？

标签： php symfony

【解决方案1】：

文档没有错误！他们在示例中没有使用类型提示：

// src/AppBundle/Entity/Product.php
public function setBrochure($brochure)
{
    $this->brochure = $brochure;

    return $this;
}

当您使用string 类型提示时，将调用 UploadedFile::__toString()！所以检查你的实体。应该是这样的：

public function setPoster($poster)
{
   // ...
}

【讨论】：

有史以来最合乎逻辑的最佳答案。我怎么会错过那个小细节...谢谢！

【解决方案2】：

要从请求中获取文件，在 Symfony 中，您需要获取 $request->files。例如$request->files->get('file_name');。

【讨论】：

【解决方案3】：

文档有误，应该是：$file = $form->get('poster')->getData();

/**
     * @param Request $request
     * @return Response
     */
    public function createAction(Request $request)
    {
        $documentary = new Documentary();

        $form = $this->createForm(DocumentaryType::class, $documentary);
        $form->handleRequest($request);

        if ($form->isSubmitted() && $form->isValid()) {
            $file = $form->get('poster')->getData();

            $posterUploader = $this->getPosterUploader();
            $fileName = $posterUploader->upload($file);

            $documentary->setPoster($fileName);

            $documentaryService = $this->getDocumentaryService();
            $documentaryService->save($documentary);
        }

        return $this->render('DocumentaryBundle:Admin:create.html.twig', [
            'form' => $form->createView(),
        ]);
    }

【讨论】：