class PDFPreviewGenerator in PDFPreview 8

Generates PDF Previews.

Hierarchy

• class \Drupal\pdfpreview\PDFPreviewGenerator

2 files declare their use of PDFPreviewGenerator

PDFPreviewFormatter.php in src/Plugin/Field/FieldFormatter/PDFPreviewFormatter.php

PDFPreviewGeneratorTest.php in tests/src/Unit/PDFPreviewGeneratorTest.php

1 string reference to 'PDFPreviewGenerator'

pdfpreview.services.yml in ./pdfpreview.services.yml

pdfpreview.services.yml

1 service uses PDFPreviewGenerator

pdfpreview.generator in ./pdfpreview.services.yml

Drupal\pdfpreview\PDFPreviewGenerator

File

src/PDFPreviewGenerator.php, line 15

Namespace

Drupal\pdfpreview

class PDFPreviewGenerator {

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

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

  /**
   * The transliteration service.
   *
   * @var \Drupal\Component\Transliteration\TransliterationInterface
   */
  protected $transliteration;

  /**
   * The toolkit manager service.
   *
   * @var \Drupal\Core\ImageToolkit\ImageToolkitManager
   */
  protected $toolkitManager;

  /**
   * The language manager service.
   *
   * @var \Drupal\Core\Language\LanguageManagerInterface
   */
  protected $languageManager;

  /**
   * Constructs a PDFPreviewGenerator object.
   *
   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
   *   The config factory.
   * @param \Drupal\Core\File\FileSystemInterface $file_system
   *   The file system service.
   * @param \Drupal\Component\Transliteration\TransliterationInterface $transliteration
   *   The transliteration service.
   * @param \Drupal\Core\ImageToolkit\ImageToolkitManager $toolkit_manager
   *   The image toolkit plugin manager service..
   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
   *   The language manager service.
   */
  public function __construct(ConfigFactoryInterface $config_factory, FileSystemInterface $file_system, TransliterationInterface $transliteration, ImageToolkitManager $toolkit_manager, LanguageManagerInterface $language_manager) {
    $this->configFactory = $config_factory;
    $this->fileSystem = $file_system;
    $this->transliteration = $transliteration;
    $this->toolkitManager = $toolkit_manager;
    $this->languageManager = $language_manager;
  }

  /**
   * Gets the preview image if it exists, or creates it if it doesnt.
   *
   * @param \Drupal\file\Entity\File $file
   *   The file to generate a preview for.
   */
  public function getPDFPreview(File $file) {
    $destination_uri = $this
      ->getDestinationURI($file);

    // Check if a preview already exists.
    if (file_exists($destination_uri)) {

      // Check if the existing preview is older than the file itself.
      if (filemtime($file
        ->getFileUri()) <= filemtime($destination_uri)) {

        // The existing preview can be used, nothing to do.
        return $destination_uri;
      }
      else {

        // Delete the existing but out-of-date preview.
        $this
          ->deletePDFPreview($file);
      }
    }
    if ($this
      ->createPDFPreview($file, $destination_uri)) {
      return $destination_uri;
    }
  }

  /**
   * Deletes the preview image for a file.
   *
   * @param \Drupal\file\Entity\File $file
   *   The file to delete the preview for.
   */
  public function deletePDFPreview(File $file) {
    $uri = $this
      ->getDestinationURI($file);
    $this->fileSystem
      ->delete($uri);
    image_path_flush($uri);
  }

  /**
   * Deletes the preview image for a file when the file is updated.
   *
   * @param \Drupal\file\Entity\File $file
   *   The file to delete the preview for.
   */
  public function updatePDFPreview(File $file) {

    /** @var \Drupal\file\Entity\File $original */
    $original = $file->original;
    if ($file
      ->getFileUri() != $original
      ->getFileUri() || filesize($file
      ->getFileUri()) != filesize($original
      ->getFileUri())) {
      $this
        ->deletePDFPreview($original);
    }
  }

  /**
   * Creates a preview image of the first page of a PDF file.
   *
   * @param \Drupal\file\Entity\File $file
   *   The file to generate a preview for.
   * @param string $destination
   *   The URI where the preview should be created.
   *
   * @return bool
   *   TRUE if the preview was successfully generated, FALSE is otherwise.
   */
  protected function createPDFPreview(File $file, $destination) {
    $file_uri = $file
      ->getFileUri();
    $local_path = $this->fileSystem
      ->realpath($file_uri);
    $config = $this->configFactory
      ->get('pdfpreview.settings');

    /** @var \Drupal\imagemagick\Plugin\ImageToolkit\ImagemagickToolkit $toolkit */
    $toolkit = $this->toolkitManager
      ->createInstance('imagemagick');
    $directory = $this->fileSystem
      ->dirname($destination);
    $this->fileSystem
      ->prepareDirectory($directory, FileSystemInterface::CREATE_DIRECTORY);
    $toolkit
      ->arguments()
      ->add('-background white');
    $toolkit
      ->arguments()
      ->add('-flatten');
    $toolkit
      ->arguments()
      ->add('-resize ' . $toolkit
      ->arguments()
      ->escape($config
      ->get('size')));
    $toolkit
      ->arguments()
      ->add('-quality ' . $toolkit
      ->arguments()
      ->escape($config
      ->get('quality')));
    if ($config
      ->get('type') == 'png') {
      $toolkit
        ->arguments()
        ->setDestinationFormat('PNG');
    }
    else {
      $toolkit
        ->arguments()
        ->setDestinationFormat('JPG');
    }
    $toolkit
      ->arguments()
      ->setSourceFormat('PDF');
    $toolkit
      ->arguments()
      ->setSourceLocalPath($local_path);
    $toolkit
      ->arguments()
      ->setSourceFrames('[0]');
    return $toolkit
      ->save($destination);
  }

  /**
   * Gets the destination URI of the file.
   *
   * @param \Drupal\file\Entity\File $file
   *   The file that is being converted.
   *
   * @return string
   *   The destination URI.
   */
  protected function getDestinationURI(File $file) {
    $config = $this->configFactory
      ->get('pdfpreview.settings');
    $scheme = $this->configFactory
      ->get('system.file')
      ->get('default_scheme');
    $langcode = $this->languageManager
      ->getCurrentLanguage()
      ->getId();
    $output_path = $scheme . '://' . $config
      ->get('path');
    if ($config
      ->get('filenames') == 'human') {
      $filename = $this->fileSystem
        ->basename($file
        ->getFileUri(), '.pdf');
      $filename = $this->transliteration
        ->transliterate($filename, $langcode);
      $filename = $file
        ->id() . '-' . $filename;
    }
    else {
      $filename = md5('pdfpreview' . $file
        ->id());
    }
    if ($config
      ->get('type') == 'png') {
      $extension = '.png';
    }
    else {
      $extension = '.jpg';
    }
    return $output_path . '/' . $filename . $extension;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
PDFPreviewGenerator::$configFactory	protected	property	Config factory.
PDFPreviewGenerator::$fileSystem	protected	property	The file system service.
PDFPreviewGenerator::$languageManager	protected	property	The language manager service.
PDFPreviewGenerator::$toolkitManager	protected	property	The toolkit manager service.
PDFPreviewGenerator::$transliteration	protected	property	The transliteration service.
PDFPreviewGenerator::createPDFPreview	protected	function	Creates a preview image of the first page of a PDF file.
PDFPreviewGenerator::deletePDFPreview	public	function	Deletes the preview image for a file.
PDFPreviewGenerator::getDestinationURI	protected	function	Gets the destination URI of the file.
PDFPreviewGenerator::getPDFPreview	public	function	Gets the preview image if it exists, or creates it if it doesnt.
PDFPreviewGenerator::updatePDFPreview	public	function	Deletes the preview image for a file when the file is updated.
PDFPreviewGenerator::__construct	public	function	Constructs a PDFPreviewGenerator object.