Symfony2 - Undefined property in entity for file upload - symfony

Question

I am getting the following error when trying to upload a file, it's odd because I've used the same code on other projects without any problems/errors.
What am I missing here?
Notice: Undefined property: Acme\DemoBundle\Entity\Article::$file in /var/www/html/InsideFight/src/Acme/DempBundle/Entity/Article.php line 277
The problem line is:
if (null !== $this->file) {
I do not have any file upload code in my controller it's being handled in the entity.
Entity
public $file;
public function getUploadDir()
{
return 'images/';
}
public function getUploadRootDir()
{
return __DIR__ . '/../../../../web/' . $this->getUploadDir();
}
public function getWebPath()
{
return null === $this->image ? null : $this->getUploadDir() . '/' . $this->image;
}
public function getAbsolutePath()
{
return null === $this->image ? null : $this->getUploadRootDir() . '/' . $this->image;
}
/**
* #ORM\PrePersist()
* #ORM\PreUpdate()
*/
public function preUpload()
{
if (null !== $this->file) {
$this->image = uniqid() . '.' . $this->file->guessExtension();
}
}
/**
* #ORM\PostPersist()
* #ORM\PostUpdate()
*/
public function upload()
{
if (null === $this->file) {
return;
}
// If there is an error when moving the file, an exception will
// be automatically thrown by move(). This will properly prevent
// the entity from being persisted to the database on error
$this->file->move($this->getUploadRootDir(), $this->image);
unset($this->file);
}
/**
* #ORM\PostRemove()
*/
public function removeUpload()
{
if ($file = $this->getAbsolutePath()) {
unlink($file);
}
}

Answer 1

Thats because you do unset($this->file);. Change it to $this->file = null.

Answer 2

Include the following namespace.
use Symfony\Component\HttpFoundation\File\UploadedFile;
Make the file variable private and create a temp file variable.
private $file;
private $tempFile
Then create getter and setter methods for $file.
public function getFile()
{
return $this->file;
}
public function setFile(UploadedFile $file = null)
{
$this->file = $file;
if (isset($this->image)) {
// store the old name to delete after the update
$this->tempfile = $this->image;
$this->image = null;
} else {
$this->image = 'initial';
}
}
Then, modify preUpload and upload functions.
public function upload()
{
if (null === $this->getFile()) {
return;
}
// if there is an error when moving the file, an exception will
// be automatically thrown by move(). This will properly prevent
// the entity from being persisted to the database on error
$this->getFile()->move($this->getUploadRootDir(), $this->image);
// check if we have an old image
if (isset($this->tempFile)) {
// delete the old image
unlink($this->getUploadRootDir() . '/' . $this->tempFile);
// clear the temp image path
$this->tempFile = null;
}
$this->file = null;
}
public function preUpload()
{
if (null !== $this->getFile()) {
// generate a unique name
$filename = uniqid();
$this->image = $filename . '.' . $this->getFile()->guessExtension();
}
}