search_api_attachments-8.x-1.0-beta16/src/Plugin/search_api_attachments/PythonPdf2txtExtractor.php

<?php

namespace Drupal\search_api_attachments\Plugin\search_api_attachments;

use Drupal\Core\Form\FormStateInterface;
use Drupal\file\Entity\File;
use Drupal\search_api_attachments\TextExtractorPluginBase;

/**
 * Provides python pdf2text extractor.
 *
 * @SearchApiAttachmentsTextExtractor(
 *   id = "python_pdf2txt_extractor",
 *   label = @Translation("Python Pdf2txt Extractor"),
 *   description = @Translation("Adds python Pdf2txt extractor support."),
 * )
 */
class PythonPdf2txtExtractor extends TextExtractorPluginBase {

  /**
   * Extract file with python Pdf2txt library.
   *
   * @param \Drupal\file\Entity\File $file
   *   A file object.
   *
   * @return string
   *   The text extracted from the file.
   */
  public function extract(File $file) {
    if (in_array($file->getMimeType(), $this->getPdfMimeTypes())) {
      $output = '';
      $filepath = $this->getRealpath($file->getFileUri());
      // Restore the locale.
      $python_path = $this->configuration['python_path'];
      $python_pdf2txt_script = realpath($this->configuration['python_pdf2txt_script']);
      $cmd = escapeshellcmd($python_path) . ' ' . escapeshellarg($python_pdf2txt_script) . ' -C -t text ' . escapeshellarg($filepath);

      // UTF-8 multibyte characters will be stripped by escapeshellargs() for
      // the default C-locale.
      // So temporarily set the locale to UTF-8 so that the filepath remains
      // valid.
      $backup_locale = setlocale(LC_CTYPE, '0');
      setlocale(LC_CTYPE, $backup_locale);
      // Support UTF-8 commands.
      // @see http://www.php.net/manual/en/function.shell-exec.php#85095
      shell_exec("LANG=en_US.utf-8");
      $output = shell_exec($cmd);
      if (is_null($output)) {
        throw new \Exception('Python Pdf2txt Extractor is not available.');
      }
      return $output;
    }
    else {
      return NULL;
    }
  }

  /**
   * {@inheritdoc}
   */
  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
    $form['python_path'] = [
      '#type' => 'textfield',
      '#title' => $this->t('Path to python executable'),
      '#description' => $this->t('Enter the path to python executable. Example: "python".'),
      '#default_value' => $this->configuration['python_path'],
      '#required' => TRUE,
    ];
    $form['python_pdf2txt_script'] = [
      '#type' => 'textfield',
      '#title' => $this->t('Full path to the python pdf2txt script'),
      '#description' => $this->t('Enter the full path to the python pdf2txt script. Example: "/usr/bin/pdf2txt.py".'),
      '#default_value' => $this->configuration['python_pdf2txt_script'],
      '#required' => TRUE,
    ];
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function validateConfigurationForm(array &$form, FormStateInterface $form_state) {
    $values = $form_state->getValue(['text_extractor_config']);
    $python_path = $values['python_path'];
    $python_pdf2txt_script = $values['python_pdf2txt_script'];

    // Check that the file exists.
    if (!file_exists($python_pdf2txt_script)) {
      $form_state->setError($form['text_extractor_config']['python_pdf2txt_script'], $this->t('The file %path does not exist.', ['%path' => $python_pdf2txt_script]));
    }
    // Check that the file is an executable Python Script.
    else {
      $cmd = escapeshellcmd($python_path) . ' ' . escapeshellarg($python_pdf2txt_script);
      exec($cmd, $output, $return_code);
      // $return_code = 1 if it fails. 100 instead.
      if ($return_code != 100) {
        $form_state->setError($form['text_extractor_config']['python_path'], '');
        $form_state->setError($form['text_extractor_config']['python_pdf2txt_script'], $this->t('Python Pdf2txt script file is not executable.'));
      }
    }
  }

  /**
   * {@inheritdoc}
   */
  public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
    $this->configuration['python_path'] = $form_state->getValue(['text_extractor_config', 'python_path']);
    $this->configuration['python_pdf2txt_script'] = $form_state->getValue([
      'text_extractor_config',
      'python_pdf2txt_script',
    ]);
    parent::submitConfigurationForm($form, $form_state);
  }

}