class FileAccessControlHandler in Drupal 8

Provides a File access control handler.

Hierarchy

• class \Drupal\Core\Entity\EntityHandlerBase uses DependencySerializationTrait, StringTranslationTrait
  • class \Drupal\Core\Entity\EntityAccessControlHandler implements EntityAccessControlHandlerInterface
    • class \Drupal\file\FileAccessControlHandler

1 file declares its use of FileAccessControlHandler

FileTestAccessControlHandler.php in core/modules/file/tests/file_test/src/FileTestAccessControlHandler.php

File

core/modules/file/src/FileAccessControlHandler.php, line 16

Namespace

Drupal\file

class FileAccessControlHandler extends EntityAccessControlHandler {

  /**
   * {@inheritdoc}
   */
  protected function checkAccess(EntityInterface $entity, $operation, AccountInterface $account) {

    /** @var \Drupal\file\FileInterface $entity */
    if ($operation == 'download' || $operation == 'view') {
      if (\Drupal::service('stream_wrapper_manager')
        ->getScheme($entity
        ->getFileUri()) === 'public') {
        if ($operation === 'download') {
          return AccessResult::allowed();
        }
        else {
          return AccessResult::allowedIfHasPermission($account, 'access content');
        }
      }
      elseif ($references = $this
        ->getFileReferences($entity)) {
        foreach ($references as $field_name => $entity_map) {
          foreach ($entity_map as $referencing_entity_type => $referencing_entities) {

            /** @var \Drupal\Core\Entity\EntityInterface $referencing_entity */
            foreach ($referencing_entities as $referencing_entity) {
              $entity_and_field_access = $referencing_entity
                ->access('view', $account, TRUE)
                ->andIf($referencing_entity->{$field_name}
                ->access('view', $account, TRUE));
              if ($entity_and_field_access
                ->isAllowed()) {
                return $entity_and_field_access;
              }
            }
          }
        }
      }
      elseif ($entity
        ->getOwnerId() == $account
        ->id()) {

        // This case handles new nodes, or detached files. The user who uploaded
        // the file can access it even if it's not yet used.
        if ($account
          ->isAnonymous()) {

          // For anonymous users, only the browser session that uploaded the
          // file is positively allowed access to it. See file_save_upload().
          // @todo Implement \Drupal\Core\Entity\EntityHandlerInterface so that
          //   services can be more properly injected.
          $allowed_fids = \Drupal::service('session')
            ->get('anonymous_allowed_file_ids', []);
          if (!empty($allowed_fids[$entity
            ->id()])) {
            return AccessResult::allowed()
              ->addCacheContexts([
              'session',
              'user',
            ]);
          }
        }
        else {
          return AccessResult::allowed()
            ->addCacheContexts([
            'user',
          ]);
        }
      }
    }
    if ($operation == 'delete' || $operation == 'update') {
      $account = $this
        ->prepareUser($account);
      $file_uid = $entity
        ->get('uid')
        ->getValue();

      // Only the file owner can update or delete the file entity.
      if ($account
        ->id() == $file_uid[0]['target_id']) {
        return AccessResult::allowed();
      }
      return AccessResult::forbidden('Only the file owner can update or delete the file entity.');
    }

    // No opinion.
    return AccessResult::neutral();
  }

  /**
   * Wrapper for file_get_file_references().
   *
   * @param \Drupal\file\FileInterface $file
   *   The file object for which to get references.
   *
   * @return array
   *   A multidimensional array. The keys are field_name, entity_type,
   *   entity_id and the value is an entity referencing this file.
   *
   * @see file_get_file_references()
   */
  protected function getFileReferences(FileInterface $file) {
    return file_get_file_references($file, NULL, EntityStorageInterface::FIELD_LOAD_REVISION, NULL);
  }

  /**
   * {@inheritdoc}
   */
  protected function checkFieldAccess($operation, FieldDefinitionInterface $field_definition, AccountInterface $account, FieldItemListInterface $items = NULL) {

    // Deny access to fields that should only be set on file creation, and
    // "status" which should only be changed based on a file's usage.
    $create_only_fields = [
      'uri',
      'filemime',
      'filesize',
    ];

    // The operation is 'edit' when the entity is being created or updated.
    // Determine if the entity is being updated by checking if it is new.
    $field_name = $field_definition
      ->getName();
    if ($operation === 'edit' && $items && ($entity = $items
      ->getEntity()) && !$entity
      ->isNew() && in_array($field_name, $create_only_fields, TRUE)) {
      return AccessResult::forbidden();
    }

    // Regardless of whether the entity exists access should be denied to the
    // status field as this is managed via other APIs, for example:
    // - \Drupal\file\FileUsage\FileUsageBase::add()
    // - \Drupal\file\Plugin\EntityReferenceSelection\FileSelection::createNewEntity()
    if ($operation === 'edit' && $field_name === 'status') {
      return AccessResult::forbidden();
    }
    return parent::checkFieldAccess($operation, $field_definition, $account, $items);
  }

  /**
   * {@inheritdoc}
   */
  protected function checkCreateAccess(AccountInterface $account, array $context, $entity_bundle = NULL) {

    // The file entity has no "create" permission because by default Drupal core
    // does not allow creating file entities independently. It allows you to
    // create file entities that are referenced from another entity
    // (e.g. an image for a article). A contributed module is free to alter
    // this to allow file entities to be created directly.
    return AccessResult::neutral();
  }

}

Members

Name	Modifiers	Type	Description	Overrides
DependencySerializationTrait::$_entityStorages	protected	property	An array of entity type IDs keyed by the property name of their storages.
DependencySerializationTrait::$_serviceIds	protected	property	An array of service IDs keyed by property name used for serialization.
DependencySerializationTrait::__sleep	public	function		1
DependencySerializationTrait::__wakeup	public	function		2
EntityAccessControlHandler::$accessCache	protected	property	Stores calculated access check results.
EntityAccessControlHandler::$entityType	protected	property	Information about the entity type.
EntityAccessControlHandler::$entityTypeId	protected	property	The entity type ID of the access control handler instance.
EntityAccessControlHandler::$viewLabelOperation	protected	property	Allows to grant access to just the labels.	5
EntityAccessControlHandler::access	public	function	Checks access to an operation on a given entity or entity translation. Overrides EntityAccessControlHandlerInterface::access	1
EntityAccessControlHandler::createAccess	public	function	Checks access to create an entity. Overrides EntityAccessControlHandlerInterface::createAccess	1
EntityAccessControlHandler::fieldAccess	public	function	Checks access to an operation on a given entity field. Overrides EntityAccessControlHandlerInterface::fieldAccess
EntityAccessControlHandler::getCache	protected	function	Tries to retrieve a previously cached access value from the static cache.
EntityAccessControlHandler::prepareUser	protected	function	Loads the current account object, if it does not exist yet.
EntityAccessControlHandler::processAccessHookResults	protected	function	We grant access to the entity if both of these conditions are met:
EntityAccessControlHandler::resetCache	public	function	Clears all cached access checks. Overrides EntityAccessControlHandlerInterface::resetCache
EntityAccessControlHandler::setCache	protected	function	Statically caches whether the given user has access.
EntityAccessControlHandler::__construct	public	function	Constructs an access control handler instance.	5
EntityHandlerBase::$moduleHandler	protected	property	The module handler to invoke hooks on.	2
EntityHandlerBase::moduleHandler	protected	function	Gets the module handler.	2
EntityHandlerBase::setModuleHandler	public	function	Sets the module handler for this handler.
FileAccessControlHandler::checkAccess	protected	function	Performs access checks. Overrides EntityAccessControlHandler::checkAccess	1
FileAccessControlHandler::checkCreateAccess	protected	function	Performs create access checks. Overrides EntityAccessControlHandler::checkCreateAccess
FileAccessControlHandler::checkFieldAccess	protected	function	Default field access as determined by this access control handler. Overrides EntityAccessControlHandler::checkFieldAccess
FileAccessControlHandler::getFileReferences	protected	function	Wrapper for file_get_file_references().
StringTranslationTrait::$stringTranslation	protected	property	The string translation service.	1
StringTranslationTrait::formatPlural	protected	function	Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals	protected	function	Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation	protected	function	Gets the string translation service.
StringTranslationTrait::setStringTranslation	public	function	Sets the string translation service to use.	2
StringTranslationTrait::t	protected	function	Translates a string to the current language or to a given language.