vich uploader bundleのassetの改良版

services.yml

services:
    app_bundle.twig.vich_uri_extension:
        class: AppBundle\Twig\Excetsion\VichUriExtension
        arguments:
            - "@vich_uploader.templating.helper.uploader_helper"
        calls:
            - [setRequest, ["@request_stack"]]
        tags:
            - { name: twig.extension }  

VichUriExtension.php

<?php
/**
 * Created by PhpStorm.
 * User: polidog
 * Date: 2016/05/26
 */

namespace AppBundle\Twig\Excetsion;


use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\RequestStack;
use Vich\UploaderBundle\Templating\Helper\UploaderHelper;

/**
 * Class VichUriExtension
 */
class VichUriExtension extends \Twig_Extension
{
    /**
     * @var UploaderHelper $helper
     */
    private $helper;

    /**
     * @var Request
     */
    private $request;

    /**
     * Constructs a new instance of UploaderExtension.
     *
     * @param UploaderHelper $helper
     */
    public function __construct(UploaderHelper $helper)
    {
        $this->helper = $helper;
    }

    /**
     * @param RequestStack $requestStack
     * @return $this
     */
    public function setRequest(RequestStack $requestStack)
    {
        $this->request = $requestStack->getCurrentRequest();
        return $this;
    }



    public function getName()
    {
        return 'vich_uri';
    }


    /**
     * Returns a list of twig functions.
     *
     * @return array An array
     */
    public function getFunctions()
    {
        $names = array(
            'vich_uri' => 'asset'
        );

        $funcs = array();
        foreach ($names as $twig => $local) {
            $funcs[$twig] = new \Twig_SimpleFunction($twig,[$this, $local]);
        }

        return $funcs;
    }

    public function asset($obj, $fieldName, $className = null)
    {
        return $this->request->getUriForPath($this->helper->asset($obj, $fieldName, $className));
    }
}