ImagemagickEventSubscriber.php in ImageMagick 8.2

Namespace

Drupal\imagemagick\EventSubscriber

File

src/EventSubscriber/ImagemagickEventSubscriber.php

<?php

namespace Drupal\imagemagick\EventSubscriber;

use Drupal\Core\Config\ConfigFactoryInterface;
use Drupal\Core\File\FileSystemInterface;
use Drupal\imagemagick\Event\ImagemagickExecutionEvent;
use Drupal\imagemagick\ImagemagickExecArguments;
use Psr\Log\LoggerInterface;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;

/**
 * Imagemagick's module Event Subscriber.
 */
class ImagemagickEventSubscriber implements EventSubscriberInterface {

  /**
   * The logger service.
   *
   * @var \Psr\Log\LoggerInterface
   */
  protected $logger;

  /**
   * The configuration factory.
   *
   * @var \Drupal\Core\Config\ConfigFactoryInterface
   */
  protected $configFactory;

  /**
   * The mudule configuration settings.
   *
   * @var \Drupal\Core\Config\ImmutableConfig
   */
  protected $imagemagickSettings;

  /**
   * The file system service.
   *
   * @var \Drupal\Core\File\FileSystemInterface
   */
  protected $fileSystem;

  /**
   * Constructs an ImagemagickEventSubscriber object.
   *
   * @param \Psr\Log\LoggerInterface $logger
   *   A logger instance.
   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
   *   The config factory.
   * @param \Drupal\Core\File\FileSystemInterface $file_system
   *   The file system service.
   */
  public function __construct(LoggerInterface $logger, ConfigFactoryInterface $config_factory, FileSystemInterface $file_system) {
    $this->logger = $logger;
    $this->configFactory = $config_factory;
    $this->imagemagickSettings = $this->configFactory
      ->get('imagemagick.settings');
    $this->fileSystem = $file_system;
  }

  /**
   * {@inheritdoc}
   */
  public static function getSubscribedEvents() {
    return [
      ImagemagickExecutionEvent::ENSURE_SOURCE_LOCAL_PATH => 'ensureSourceLocalPath',
      ImagemagickExecutionEvent::POST_SAVE => 'postSave',
      ImagemagickExecutionEvent::PRE_CONVERT_EXECUTE => 'preConvertExecute',
      ImagemagickExecutionEvent::PRE_IDENTIFY_EXECUTE => 'preIdentifyExecute',
    ];
  }

  /**
   * Ensures source image URI to a local filesystem path.
   *
   * @param \Drupal\imagemagick\ImagemagickExecArguments $arguments
   *   The ImageMagick/GraphicsMagick execution arguments object.
   */
  protected function doEnsureSourceLocalPath(ImagemagickExecArguments $arguments) {

    // Early return if already set.
    if (!empty($arguments
      ->getSourceLocalPath())) {
      return;
    }
    $source = $arguments
      ->getSource();
    if (!file_valid_uri($source)) {

      // The value of $source is likely a file path already.
      $arguments
        ->setSourceLocalPath($source);
    }
    else {

      // If we can resolve the realpath of the file, then the file is local
      // and we can assign the actual file path.
      $path = $this->fileSystem
        ->realpath($source);
      if ($path) {
        $arguments
          ->setSourceLocalPath($path);
      }
      else {

        // We are working with a remote file, copy the remote source file to a
        // temp one and set the local path to it.
        $temp_path = $this->fileSystem
          ->tempnam('temporary://', 'imagemagick_');
        $this->fileSystem
          ->unlink($temp_path);
        $temp_path .= '.' . pathinfo($source, PATHINFO_EXTENSION);
        $path = file_unmanaged_copy($arguments
          ->getSource(), $temp_path, FILE_EXISTS_ERROR);
        $arguments
          ->setSourceLocalPath($this->fileSystem
          ->realpath($path));
        drupal_register_shutdown_function([
          static::class,
          'removeTemporaryRemoteCopy',
        ], $arguments
          ->getSourceLocalPath());
      }
    }
  }

  /**
   * Ensures destination image URI to a local filesystem path.
   *
   * @param \Drupal\imagemagick\ImagemagickExecArguments $arguments
   *   The ImageMagick/GraphicsMagick execution arguments object.
   */
  protected function doEnsureDestinationLocalPath(ImagemagickExecArguments $arguments) {
    $local_path = $arguments
      ->getDestinationLocalPath();

    // Early return if already set.
    if (!empty($local_path)) {
      return;
    }
    $destination = $arguments
      ->getDestination();
    if (!file_valid_uri($destination)) {

      // The value of $destination is likely a file path already.
      $arguments
        ->setDestinationLocalPath($destination);
    }
    else {

      // If we can resolve the realpath of the file, then the file is local
      // and we can assign its real path.
      $path = $this->fileSystem
        ->realpath($destination);
      if ($path) {
        $arguments
          ->setDestinationLocalPath($path);
      }
      else {

        // We are working with a remote file, set the local destination to
        // a temp local file.
        $temp_path = $this->fileSystem
          ->tempnam('temporary://', 'imagemagick_');
        $this->fileSystem
          ->unlink($temp_path);
        $temp_path .= '.' . pathinfo($destination, PATHINFO_EXTENSION);
        $arguments
          ->setDestinationLocalPath($this->fileSystem
          ->realpath($temp_path));
        drupal_register_shutdown_function([
          static::class,
          'removeTemporaryRemoteCopy',
        ], $arguments
          ->getDestinationLocalPath());
      }
    }
  }

  /**
   * Adds configured arguments at the beginning of the list.
   *
   * @param \Drupal\imagemagick\ImagemagickExecArguments $arguments
   *   The ImageMagick/GraphicsMagick execution arguments object.
   */
  protected function prependArguments(ImagemagickExecArguments $arguments) {

    // Add prepended arguments if needed.
    if ($prepend = $this->imagemagickSettings
      ->get('prepend')) {
      $arguments
        ->add($prepend, $this->imagemagickSettings
        ->get('prepend_pre_source') ? ImagemagickExecArguments::PRE_SOURCE : ImagemagickExecArguments::POST_SOURCE, 0);
    }
  }

  /**
   * Reacts to an image being parsed.
   *
   * Alters the settings before an image is parsed by the ImageMagick toolkit.
   *
   * ImageMagick does not support stream wrappers so this method allows to
   * resolve URIs of image files to paths on the local filesystem.
   * Modules can also decide to move files from remote systems to the local
   * file system to allow processing.
   *
   * @param \Drupal\imagemagick\Event\ImagemagickExecutionEvent $event
   *   Imagemagick execution event.
   *
   * @see \Drupal\imagemagick\Plugin\ImageToolkit\ImagemagickToolkit::parseFile()
   * @see \Drupal\imagemagick\ImagemagickExecArguments::getSource()
   * @see \Drupal\imagemagick\ImagemagickExecArguments::setSourceLocalPath()
   * @see \Drupal\imagemagick\ImagemagickExecArguments::getSourceLocalPath()
   */
  public function ensureSourceLocalPath(ImagemagickExecutionEvent $event) {
    $arguments = $event
      ->getExecArguments();
    $this
      ->doEnsureSourceLocalPath($arguments);
  }

  /**
   * Reacts to an image save.
   *
   * Alters an image after it has been converted by the ImageMagick toolkit.
   *
   * ImageMagick does not support remote file systems, so modules can decide
   * to move temporary files from the local file system to remote destination
   * systems.
   *
   * @param \Drupal\imagemagick\Event\ImagemagickExecutionEvent $event
   *   Imagemagick execution event.
   *
   * @see \Drupal\imagemagick\Plugin\ImageToolkit\ImagemagickToolkit::save()
   * @see \Drupal\imagemagick\ImagemagickExecArguments::getDestination()
   * @see \Drupal\imagemagick\ImagemagickExecArguments::getDestinationLocalPath()
   */
  public function postSave(ImagemagickExecutionEvent $event) {
    $arguments = $event
      ->getExecArguments();
    $destination = $arguments
      ->getDestination();
    if (!$this->fileSystem
      ->realpath($destination)) {

      // We are working with a remote file, so move the temp file to the final
      // destination, replacing any existing file with the same name.
      file_unmanaged_move($arguments
        ->getDestinationLocalPath(), $arguments
        ->getDestination(), FILE_EXISTS_REPLACE);
    }
  }

  /**
   * Fires before the 'identify' command is executed.
   *
   * It allows to change file paths for source and destination image files,
   * and/or to alter the command line arguments that are passed to the binaries.
   * The toolkit provides methods to prepend, add, find, get and reset
   * arguments that have already been set by image effects.
   *
   * In addition to arguments that are passed to the binaries command line for
   * execution, it is possible to push arguments to be used only by the toolkit
   * or the event subscribers. You can add/get/find such arguments by specifying
   * ImagemagickExecArguments::INTERNAL as the argument $mode in the methods.
   *
   * @param \Drupal\imagemagick\Event\ImagemagickExecutionEvent $event
   *   Imagemagick execution event.
   *
   * @see http://www.imagemagick.org/script/command-line-processing.php#output
   *
   * @see \Drupal\imagemagick\ImagemagickExecArguments
   * @see \Drupal\imagemagick\Plugin\FileMetadata\ImagemagickIdentify::identify()
   */
  public function preIdentifyExecute(ImagemagickExecutionEvent $event) {
    $arguments = $event
      ->getExecArguments();
    $this
      ->prependArguments($arguments);
  }

  /**
   * Fires before the 'convert' command is executed.
   *
   * It allows to change file paths for source and destination image files,
   * and/or to alter the command line arguments that are passed to the binaries.
   * The toolkit provides methods to prepend, add, find, get and reset
   * arguments that have already been set by image effects.
   *
   * In addition to arguments that are passed to the binaries command line for
   * execution, it is possible to push arguments to be used only by the toolkit
   * or the event subscribers. You can add/get/find such arguments by specifying
   * ImagemagickExecArguments::INTERNAL as the argument $mode in the methods.
   *
   * ImageMagick automatically converts the target image to the format denoted
   * by the file extension. However, since changing the file extension is not
   * always an option, you can specify an alternative image format via
   * $arguments->setDestinationFormat('format'), where 'format' is a string
   * denoting an Imagemagick supported format, or via
   * $arguments->setDestinationFormatFromExtension('extension'), where
   * 'extension' is a string denoting an image file extension.
   *
   * When the destination format is set, it is passed to ImageMagick's convert
   * binary with the syntax "[format]:[destination]".
   *
   * @param \Drupal\imagemagick\Event\ImagemagickExecutionEvent $event
   *   Imagemagick execution event.
   *
   * @see http://www.imagemagick.org/script/command-line-processing.php#output
   * @see http://www.imagemagick.org/Usage/files/#save
   *
   * @see \Drupal\imagemagick\ImagemagickExecArguments
   * @see \Drupal\imagemagick\Plugin\ImageToolkit\ImagemagickToolkit::convert()
   */
  public function preConvertExecute(ImagemagickExecutionEvent $event) {
    $arguments = $event
      ->getExecArguments();
    $this
      ->prependArguments($arguments);
    $this
      ->doEnsureDestinationLocalPath($arguments);

    // Change output image resolution to 72 ppi, if specified in settings.
    if (empty($arguments
      ->find('/^\\-density/')) && ($density = (int) $this->imagemagickSettings
      ->get('advanced.density'))) {
      $arguments
        ->add("-density {$density} -units PixelsPerInch");
    }

    // Apply color profile.
    if ($profile = $this->imagemagickSettings
      ->get('advanced.profile')) {
      if (file_exists($profile)) {
        $arguments
          ->add('-profile ' . $arguments
          ->escape($profile));
      }
    }
    elseif ($colorspace = $this->imagemagickSettings
      ->get('advanced.colorspace')) {

      // Do not hi-jack settings made by effects.
      if (empty($arguments
        ->find('/^\\-colorspace/'))) {
        $arguments
          ->add('-colorspace ' . $arguments
          ->escape($colorspace));
      }
    }

    // Change image quality.
    if (empty($arguments
      ->find('/^\\-quality/'))) {
      $arguments
        ->add('-quality ' . $this->imagemagickSettings
        ->get('quality'));
    }
  }

  /**
   * Removes a temporary file created during operations on a remote file.
   *
   * Used with drupal_register_shutdown_function().
   *
   * @param string $path
   *   The temporary file realpath.
   */
  public static function removeTemporaryRemoteCopy($path) {
    if (file_exists($path)) {
      file_unmanaged_delete($path);
    }
  }

}

Classes

Name	Description
ImagemagickEventSubscriber	Imagemagick's module Event Subscriber.