Symfony2，文件上传 - 在编辑中删除旧文件并创建新文件

Question

我有References.php包括 Image 在内的工作实体，但我不知道如何在 Symfony2 中删除保存在此参考中的旧图像（如果存在）并创建新图像。因为现在，它并没有删除当前的图像，所以只在image_path这个实体中创建了一个新的并设置了新的。这是我尝试在preUpload方法上删除它，但它将当前文件设置为NULL然后什么都没有（所以我有错误 -你必须选择一个文件）

<?php

namespace Acme\ReferenceBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;
use Symfony\Component\HttpFoundation\File\UploadedFile;

/**
 * @ORM\Entity(repositoryClass="Acme\ReferenceBundle\Entity\ReferenceRepository")
 * @ORM\Table(name="`references`") 
 * @ORM\HasLifecycleCallbacks 
 */
class Reference
{
    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    private $id;              

    /**
     * @ORM\Column(type="string", length=200)    
     * @Assert\NotBlank(
     *      message = "Name cannot be blank"      
     * )    
     * @Assert\Length(
     *      min = "3",
     *      minMessage = "Name is too short"         
     * )     
     */     
    private $name;

    /**
     * @ORM\Column(type="string", length=200)    
     * @Assert\NotBlank(
     *      message = "Description cannot be blank"      
     * )    
     * @Assert\Length(
     *      min = "3",
     *      minMessage = "Description is too short"         
     * )     
     */     
    private $description;

    /**
     * @ORM\Column(type="string", length=200)
     * @Assert\Url(
     *      message = "URL is not valid"
     * )          
     */     
    private $url;

    /**
     * @ORM\ManyToMany(targetEntity="Material", inversedBy="references")
     * @Assert\Count(min = 1, minMessage = "Choose any material") 
     */
    private $materials;

    /**
     * @ORM\Column(type="text", length=255, nullable=false)
     * @Assert\NotNull(
     *      message = "You have to choose a file"
     * )     
     */
    private $image_path;

    /**
     * @Assert\File(
     *     maxSize = "5M",
     *     mimeTypes = {"image/jpeg", "image/gif", "image/png", "image/tiff"},
     *     maxSizeMessage = "Max size of file is 5MB.",
     *     mimeTypesMessage = "There are only allowed jpeg, gif, png and tiff images"
     * )
     */
    private $file;                  

    /**
     * Get id
     *
     * @return integer 
     */
    public function getId()
    {
        return $this->id;
    }

    /**
     * Set name
     *
     * @param string $name
     * @return Reference
     */
    public function setName($name)
    {
        $this->name = $name;

        return $this;
    }

    /**
     * Get name
     *
     * @return string 
     */
    public function getName()
    {
        return $this->name;
    }

    /**
     * Set description
     *
     * @param string $description
     * @return Reference
     */
    public function setDescription($description)
    {
        $this->description = $description;

        return $this;
    }

    /**
     * Get description
     *
     * @return string 
     */
    public function getDescription()
    {
        return $this->description;
    }

    /**
     * Set url
     *
     * @param string $url
     * @return Reference
     */
    public function setUrl($url)
    {
        $this->url = $url;

        return $this;
    }

    /**
     * Get url
     *
     * @return string 
     */
    public function getUrl()
    {
        return $this->url;
    }

    /**
     * Set materials
     *
     * @param string $materials
     * @return Reference
     */
    public function setMaterials($materials)
    {
        $this->materials = $materials;

        return $this;
    }

    /**
     * Get materials
     *
     * @return string 
     */
    public function getMaterials()
    {
        return $this->materials;
    }

    /**
     * Set image_path
     *
     * @param string $imagePath
     * @return Reference
     */
    public function setImagePath($imagePath)
    {
        $this->image_path = $imagePath;

        return $this;
    }

    /**
     * Get image_path
     *
     * @return string 
     */
    public function getImagePath()
    {
        return $this->image_path;
    }

    public function setFile(UploadedFile $file = null)
    {
        $this->file = $file;
    }

    /**
     * Get file.
     *
     * @return UploadedFile
     */
    public function getFile()
    {
        return $this->file;
    }

    /**
    * Called before saving the entity
    * 
    * @ORM\PrePersist()
    * @ORM\PreUpdate()
    */
    public function preUpload()
    {   
        $oldImage = $this->image_path;
        $oldImagePath = $this->getUploadRootDir().'/'.$oldImage;

        if (null !== $this->file) {
            if($oldImage && file_exists($oldImagePath)) unlink($oldImagePath); // not working correctly
            $filename = sha1(uniqid(mt_rand(), true));
            $this->image_path = $filename.'.'.$this->file->guessExtension();
        }
    }

    /**
    * Called before entity removal
    *
    * @ORM\PostRemove()
    */
    public function removeUpload()
    {
        if ($file = $this->getAbsolutePath()) {
            unlink($file);
        }
    }

    /**
    * Called after entity persistence
    *
    * @ORM\PostPersist()
    * @ORM\PostUpdate()
    */
    public function upload()
    {
        // the file property can be empty if the field is not required
        if (null === $this->file) {
            return;
        }

        // use the original file name here but you should
        // sanitize it at least to avoid any security issues

        // move takes the target directory and then the
        // target filename to move to
        $this->file->move(
            $this->getUploadRootDir(),
            $this->image_path
        );

        // set the path property to the filename where you've saved the file
        $this->image_path = $this->file->getClientOriginalName();

        // clean up the file property as you won't need it anymore
        $this->file = null;
    }

    protected function getAbsolutePath()
    {
        return null === $this->image_path
            ? null
            : $this->getUploadRootDir().'/'.$this->image_path;
    }

    protected function getUploadRootDir()
    {
        // the absolute directory path where uploaded
        // documents should be saved
        return __DIR__.'/../../../../'.$this->getUploadDir();
    }

    protected function getUploadDir()
    {
        // get rid of the __DIR__ so it doesn't screw up
        // when displaying uploaded doc/image in the view.
        return 'uploads/references';
    }

    public function getWebPath()
    {
        return $this->getUploadDir().'/'.$this->image_path;
    }
    /**
     * Constructor
     */
    public function __construct()
    {
        $this->materials = new \Doctrine\Common\Collections\ArrayCollection();
    }

    /**
     * Add materials
     *
     * @param \Acme\ReferenceBundle\Entity\Material $materials
     * @return Reference
     */
    public function addMaterial(\Acme\ReferenceBundle\Entity\Material $materials)
    {
        $this->materials[] = $materials;

        return $this;
    }

    /**
     * Remove materials
     *
     * @param \Acme\ReferenceBundle\Entity\Material $materials
     */
    public function removeMaterial(\Acme\ReferenceBundle\Entity\Material $materials)
    {
        $this->materials->removeElement($materials);
    }
}

任何的想法？

Answer 1

所以我找到了解决方案。首先，我必须为文件上传创建一个 Assert 回调，因为我将NotNull()Assert 用于Reference实体。所以如果我选择任何文件并发送表单，我总是收到错误You have to choose a file。所以我的第一次编辑在这里：

use Symfony\Component\Validator\ExecutionContextInterface;      // <-- here

/**
 * @ORM\Entity(repositoryClass="Acme\ReferenceBundle\Entity\ReferenceRepository")
 * @ORM\Table(name="`references`") 
 * @ORM\HasLifecycleCallbacks 
 * @Assert\Callback(methods={"isFileUploadedOrExists"})       <--- and here
 */
class Reference
{
    // code
}

然后在我的代码中添加一个新方法：

public function isFileUploadedOrExists(ExecutionContextInterface $context)
{
    if(null === $this->image_path && null === $this->file)
        $context->addViolationAt('file', 'You have to choose a file', array(), null);   
}

我也删除NotNull了我的$image_path财产中的断言。

然后它工作成功 - 如果我选择了一个文件并提交了表格，参考是用图像创建的。但它还没有完成。我在这个问题中提出了我的问题 - 当然，删除旧图像并使用新路径创建新图像。

经过多次实验，我找到了有效且美观的解决方案。在我的控制器中，我在表单验证之前和用于删除旧图像之后添加了一个变量：

$oldImagePath = $reference->getImagePath(); // get path of old image

if($form->isValid())
{
    if ($form->get('file')->getData() !== null) { // if any file was updated
        $file = $form->get('file')->getData();
        $reference->removeFile($oldImagePath); // remove old file, see this at the bottom
        $reference->setImagePath($file->getClientOriginalName()); // set Image Path because preUpload and upload method will not be called if any doctrine entity will not be changed. It tooks me long time to learn it too.
    }
    $em->persist($reference);
    try {
        $em->flush();
    } catch (\PDOException $e) {
        //sth
    }

还有我的removeFile()方法：

public function removeFile($file)
{
    $file_path = $this->getUploadRootDir().'/'.$file;
    if(file_exists($file_path)) unlink($file_path);
}

最后，我删除$this->image_path = $this->file->getClientOriginalName();了upload()方法中的行，因为它会导致表单中的预览图像出现问题（如果您使用的话）。它将原始文件名设置为路径，但是如果您重新加载页面，您将看到图像的真实路径。删除此行将解决问题。

感谢大家发布答案，谁帮助我找到解决方案。