class File

1. 9.x drupal/core/vendor/symfony/http-foundation/Symfony/Component/HttpFoundation/File/File.php \Symfony\Component\HttpFoundation\File\File
2. 9.x drupal/core/modules/file/lib/Drupal/file/Plugin/views/field/File.php \Drupal\file\Plugin\views\field\File
3. 9.x drupal/core/modules/file/lib/Drupal/file/Plugin/views/wizard/File.php \Drupal\file\Plugin\views\wizard\File
4. 9.x drupal/core/modules/file/lib/Drupal/file/Plugin/Core/Entity/File.php \Drupal\file\Plugin\Core\Entity\File

DirectoryTest::testFileCheckDirectoryHandling in drupal/core/modules/system/lib/Drupal/system/Tests/File/DirectoryTest.php

Test directory handling functions.

DirectoryTest::testFileCreateNewFilepath in drupal/core/modules/system/lib/Drupal/system/Tests/File/DirectoryTest.php

This will take a directory and path, and find a valid filepath that is not taken by another file.

DirectoryTest::testFileDestination in drupal/core/modules/system/lib/Drupal/system/Tests/File/DirectoryTest.php

This will test the filepath for a destination based on passed flags and whether or not the file exists.

FileFieldDisplayTest::getInfo in drupal/core/modules/file/lib/Drupal/file/Tests/FileFieldDisplayTest.php

FileFieldPathTest::getInfo in drupal/core/modules/file/lib/Drupal/file/Tests/FileFieldPathTest.php

... See full list

class File extends FieldPluginBase {

  /**
   * Constructor to provide additional field to add.
   */
  public function init(ViewExecutable $view, &$options) {
    parent::init($view, $options);
    if (!empty($options['link_to_file'])) {
      $this->additional_fields['uri'] = 'uri';
    }
  }
  protected function defineOptions() {
    $options = parent::defineOptions();
    $options['link_to_file'] = array(
      'default' => FALSE,
      'bool' => TRUE,
    );
    return $options;
  }

  /**
   * Provide link to file option
   */
  public function buildOptionsForm(&$form, &$form_state) {
    $form['link_to_file'] = array(
      '#title' => t('Link this field to download the file'),
      '#description' => t("Enable to override this field's links."),
      '#type' => 'checkbox',
      '#default_value' => !empty($this->options['link_to_file']),
    );
    parent::buildOptionsForm($form, $form_state);
  }

  /**
   * Render whatever the data is as a link to the file.
   *
   * Data should be made XSS safe prior to calling this function.
   */
  function render_link($data, $values) {
    if (!empty($this->options['link_to_file']) && $data !== NULL && $data !== '') {
      $this->options['alter']['make_link'] = TRUE;
      $this->options['alter']['path'] = file_create_url($this
        ->get_value($values, 'uri'));
    }
    return $data;
  }
  function render($values) {
    $value = $this
      ->get_value($values);
    return $this
      ->render_link($this
      ->sanitizeValue($value), $values);
  }

}