Q:

ContextErrorException when uploading file through VichUploaderBundle

I am trying to upload a file based on the VichUploaderBundle.
I got this error when implementing it:
ContextErrorException: Catchable Fatal Error: Argument 1 passed to Minn\AdsBundle\Entity\MotorsAdsFile::setFile() must be an instance of Symfony\Component\HttpFoundation\File\File, string given,... 

I know that the problem is the Class of the given argument in the method setFile(). But, this I have found in the documentation on github.
So, this is what I have done & I hope I will solve the problem!
configuration of the bundle
vich_uploader:
    db_driver: orm # or mongodb or propel or phpcr
    mappings:
        motors_files:
            uri_prefix:         /files/motors
            upload_destination: %kernel.root_dir%/../web/files/motors
            namer: vich_uploader.namer_origname
            delete_on_remove: true

Definition of my File entity
<?php

namespace Minn\AdsBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\HttpFoundation\File\File;
use Symfony\Component\Validator\Constraints as Assert;
use Vich\UploaderBundle\Mapping\Annotation as Vich;

/**
 * @ORM\Entity
 * @Vich\Uploadable
 */
class MotorsAdsFile {

    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    public $id;

    /**
     * @Assert\File(
     *     maxSize="5M",
     *     mimeTypes={"image/png", "image/jpeg"}
     * )
     * @Vich\UploadableField(mapping="motors_files", fileNameProperty="file")
     * note: This is not a mapped field of entity metadata, just a simple property.
     * @var File $file
     */
    protected $file;

    /**
     * @ORM\Column(type="string", length=255, name="name")
     * @var string $name
     */
    protected $name;

    /**
     * If manually uploading a file (i.e. not using Symfony Form) ensure an instance
     * of 'UploadedFile' is injected into this setter to trigger the  update. If this
     * bundle's configuration parameter 'inject_on_load' is set to 'true' this setter
     * must be able to accept an instance of 'File' as the bundle will inject one here
     * during Doctrine hydration.
     *
     * @param File|\Symfony\Component\HttpFoundation\File\UploadedFile $file
     */
    public function setFile(File $file) {
        $this->file = $file;
    }

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

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

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

}

Twig part for the form
<form action="{{ path('minn_ads_motors_test6') }}" {{ form_enctype(form) }} method="POST">
    {{ form_widget(form) }}
    <div>
        <input type="submit" value="do it with VICH" />
    </div>
</form>

my action() in my controller
public function motorstest6Action(Request $request) {
    $document = new MotorsAdsFile();
    $form = $this->createFormBuilder($document)
            ->add('name')
            ->add('file')
            ->getForm();

    $form->handleRequest($request);

    if ($form->isValid()) {
        $em = $this->getDoctrine()->getManager();
        $em->persist($document);
        $em->flush();

        return $this->redirect($this->generateUrl('minn_ads_default_index'));
    }
    return $this->render('MinnAdsBundle:Motors:adddoc1.html.twig', array(
                'form' => $form->createView()));
}

A:

Your entity isn't configured properly. In order for this bundle to work, the entity must have two fields to represent the file: one to store the File object (not mapped by doctrine) and another one to store its name (as a string, mapped by doctrine).
Your entity only has the first field.
Here is how you should have defined it:
<?php

namespace Minn\AdsBundle\Entity;

use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\HttpFoundation\File\File;
use Symfony\Component\Validator\Constraints as Assert;
use Vich\UploaderBundle\Mapping\Annotation as Vich;

/**
 * @ORM\Entity
 * @Vich\Uploadable
 */
class MotorsAdsFile {

    /**
     * @ORM\Id
     * @ORM\Column(type="integer")
     * @ORM\GeneratedValue(strategy="AUTO")
     */
    public $id;

    /**
     * @Assert\File(
     *     maxSize="5M",
     *     mimeTypes={"image/png", "image/jpeg"}
     * )
     * @Vich\UploadableField(mapping="motors_files", fileNameProperty="filename")
     * note: This is not a mapped field of entity metadata, just a simple property.
     * @var File $file
     */
    protected $file;

    /**
     * @ORM\Column(type="string", length=255, name="filename")
     * @var string $filename
     */
    protected $filename;

    /**
     * @ORM\Column(type="string", length=255, name="name")
     * @var string $name
     */
    protected $name;

    /**
     * If manually uploading a file (i.e. not using Symfony Form) ensure an instance
     * of 'UploadedFile' is injected into this setter to trigger the  update. If this
     * bundle's configuration parameter 'inject_on_load' is set to 'true' this setter
     * must be able to accept an instance of 'File' as the bundle will inject one here
     * during Doctrine hydration.
     *
     * @param File|\Symfony\Component\HttpFoundation\File\UploadedFile $file
     */
    public function setFile(File $file) {
        $this->file = $file;
    }

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

    /**
     * @param string $filenname
     */
    public function setFilename($filename) {
        $this->filename = $filename;
    }

    /**
     * @return string
     */
    public function getFilename() {
        return $this->file;
    }

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

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

Note the new filename field and the new value for the filenameProperty option in the UploadableField annotation.

