Problems With Multiple File Upload In Symfony2

Question

I am making a Symfony2 application which needs to have a multiple image upload option. I have made the single file upload using the cookbook entry: How to handle File Uploads with Doctrine which works fine. I have implemented the lifecyclecallbacks for uploading and removing.

Now I need to turn this into a multiple upload system. I have read a few answers from Stack Overflow as well, but nothing seems to work.

Stack Overflow Question:

1. Multiple file upload with Symfony2
2. multiple file upload symfony 2

I have the following code at the moment:

File Entity:

<?php
namespace Webmuch\ProductBundle\Entity;

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


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

    /**
     * @ORM\Column(type="string", length=255, nullable=true)
     */
    public $path;

    /**
     * @Assert\File(maxSize="6000000")
     */
    public $file = array();

    public function __construct()
    {

    }

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

    /**
     * Set path
     *
     * @param string $path
     */
    public function setPath($path)
    {
        $this->path = $path;
    }

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


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

    public function getWebPath()
    {
        return null === $this->path ? null : $this->getUploadDir().'/'.$this->path;
    }

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

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

    /**
     * @ORM\PrePersist()
     * @ORM\PreUpdate()
     */
    public function preUpload()
    {
        if (null !== $this->file) {
            // do whatever you want to generate a unique name
            $this->path[] = uniqid().'.'.$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->path);

        unset($this->file);
    }

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

FileController:

<?php

namespace Webmuch\ProductBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Method;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Template;

use Webmuch\ProductBundle\Entity\File;


/**
 * File controller.
 *
 * @Route("/files")
 */
class FileController extends Controller
{
    /**
     * Lists all File entities.
     *
     * @Route("/", name="file_upload")
     * @Template()
     */
    public function uploadAction()
    {
        $file = new File();
        $form = $this->createFormBuilder($file)
            ->add('file','file',array(
                    "attr" => array(
                        "accept" => "image/*",
                        "multiple" => "multiple",
                    )
                ))
            ->getForm()
        ;

        if ($this->getRequest()->getMethod() === 'POST') {
            $form->bindRequest($this->getRequest());
                $em = $this->getDoctrine()->getEntityManager();

                $em->persist($file);
                $em->flush();

                $this->redirect($this->generateUrl('file_upload'));
        }

        return array('form' => $form->createView());
    }
}

and the upload.html.twig:

{% extends '::base.html.twig' %}

{% block body %}
<h1>Upload File</h1>

<form action="#" method="post" {{ form_enctype(form) }}>

    {{ form_widget(form.file) }} 

    <input type="submit" value="Upload" />
</form>
{% endblock %}

I don't know what to do to make this work as a multiple file upload system. I have kept the comments as they are from the tutorials I have followed so I can remember what is doing what.

UPDATE:

New Form Code:

$images_form = $this->createFormBuilder($file)
    ->add('file', 'file', array(
            "attr" => array(
                "multiple" => "multiple",
                "name" => "files[]",
            )
        ))
    ->getForm()
;

New Form Twig Code:

<form action="{{ path('file_upload') }}" method="post" {{ form_enctype(images_form) }}>

    {{ form_label(images_form.file) }}
    {{ form_errors(images_form.file) }}
    {{ form_widget(images_form.file, { 'attr': {'name': 'files[]'} }) }}

    {{ form_rest(images_form) }}
    <input type="submit" />
</form>

Answer 1

This is a known issue as referenced on GitHub.

As they say, you should append [] to the full_name attribute in your template :

{{ form_widget(images_form.file, { 'full_name': images_form.file.get('full_name') ~ '[]' }) }}