Get new value of entity field after Doctrine flush - symfony

Question

I'm trying to resize an image after persisting an entity with Doctrine. In my Entity code, I'm setting a field to a specific value before the flush and the update :
/**
* #ORM\PrePersist()
* #ORM\PreUpdate()
*/
public function preUpload()
{
if (null !== $this->getFile()) {
// do whatever you want to generate a unique name
$filename = sha1(uniqid(mt_rand(), true));
$this->image = $filename.'.png';
}
}
So the image field is supposed to be updated.
Then in my controller, I'd like to do my resize job:
if ($form->isValid())
{
$em->persist($activite);
$em->flush();
//resize the image
$img_path = $activite->getImage();
resizeImage($img_path);
}
However, at this point in the code, the value of $activite->image is still null. How can I get the new value?
(Everything is saved well in the database.)

Answer 1

The EntityManager has a refresh() method to update your entity with the latest values from database.
$em->refresh($entity);

Answer 2

I found my error.
Actually, I was following this tutorial: http://symfony.com/doc/current/cookbook/doctrine/file_uploads.html
and at some point they give this code to set the file:
public function setFile(UploadedFile $file = null)
{
$this->file = $file;
// check if we have an old image path
if (isset($this->path)) {
// store the old name to delete after the update
$this->temp = $this->path;
$this->path = null;
} else {
$this->path = 'initial';
}
}
And then after the upload, in the first version (with the random filename), they do :
$this->file = null;
But then in the second version, this code is replace by:
$this->setFile(null);
My problem is that I've tried the two versions to finally come back to the first. However, I forgot to change the line to set the file to null and so everytime my path field was reset to null.
Sorry for this absurdity and thanks for your help.