CacheBustingWorker for Assetic 1.1.1

CacheBustingWorker.php

<?php

/**
 * This file is part of IBMS
 *
 * (c) Infinite Networks Pty Ltd <http://www.infinite.net.au>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Ibms\Helper;

use Assetic\Asset\AssetCollectionInterface;
use Assetic\Asset\AssetInterface;
use Assetic\Factory\Worker\CacheBustingWorker as BaseCacheBustingWorker;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Copied from Assetic due to limitations of its design which are not
 * fixed until Assetic 1.2
 */
class CacheBustingWorker extends BaseCacheBustingWorker
{
    private $container;
    private $separator;

    public function __construct(ContainerInterface $container, $separator = '-')
    {
        $this->container = $container;
        $this->separator = $separator;
    }

    public function process(AssetInterface $asset)
    {
        if (!$path = $asset->getTargetPath()) {
            // no path to work with
            return;
        }

        if (!$search = pathinfo($path, PATHINFO_EXTENSION)) {
            // nothing to replace
            return;
        }

        $replace = $this->separator.$this->getHash($asset).'.'.$search;
        if (preg_match('/'.preg_quote($replace, '/').'$/', $path)) {
            // already replaced
            return;
        }

        $asset->setTargetPath(
            preg_replace('/\.'.preg_quote($search, '/').'$/', $replace, $path)
        );
    }

    protected function getHash(AssetInterface $asset)
    {
        $hash = hash_init('sha1');

        hash_update($hash, $this->getAm()->getLastModified($asset));

        if ($asset instanceof AssetCollectionInterface) {
            foreach ($asset as $i => $leaf) {
                $sourcePath = $leaf->getSourcePath();
                hash_update($hash, $sourcePath ?: $i);
            }
        }

        return substr(hash_final($hash), 0, 7);
    }

    private function getAm()
    {
        return $this->container->get('assetic.asset_manager');
    }
}

config_prod.yml

services:
    assetic.factory_worker.cache_buster:
        class: Ibms\Helper\CacheBustingWorker
        arguments:
            - @service_container
        tags:
            - { name: assetic.factory_worker }