OptiPngFilter.php

<?php

/*
 * This file is part of the Assetic package, an OpenSky project.
 *
 * (c) 2010-2012 OpenSky Project Inc
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace Assetic\Filter;

use Assetic\Asset\AssetInterface;
use Assetic\Exception\FilterException;
use Symfony\Component\Process\ProcessBuilder;

/**
 * Runs assets through OptiPNG.
 *
 * @link   http://optipng.sourceforge.net/
 * @author Kris Wallsmith <kris.wallsmith@gmail.com>
 */
class OptiPngFilter implements FilterInterface {
  private $optipngBin;
  private $level;

  /**
   * Constructor.
   *
   * @param string $optipngBin Path to the optipng binary
   */
  public function __construct($optipngBin = '/usr/bin/optipng') {
    $this->optipngBin = $optipngBin;
  }
  public function setLevel($level) {
    $this->level = $level;
  }
  public function filterLoad(AssetInterface $asset) {
  }
  public function filterDump(AssetInterface $asset) {
    $pb = new ProcessBuilder(array(
      $this->optipngBin,
    ));
    if (null !== $this->level) {
      $pb
        ->add('-o')
        ->add($this->level);
    }
    $pb
      ->add('-out')
      ->add($output = tempnam(sys_get_temp_dir(), 'assetic_optipng'));
    unlink($output);
    $pb
      ->add($input = tempnam(sys_get_temp_dir(), 'assetic_optipng'));
    file_put_contents($input, $asset
      ->getContent());
    $proc = $pb
      ->getProcess();
    $code = $proc
      ->run();
    if (0 < $code) {
      unlink($input);
      throw FilterException::fromProcess($proc)
        ->setInput($asset
        ->getContent());
    }
    $asset
      ->setContent(file_get_contents($output));
    unlink($input);
    unlink($output);
  }

}