Version 1

[yaffs-website] / web / core / modules / file / src / FileAccessControlHandler.php

diff --git a/web/core/modules/file/src/FileAccessControlHandler.php b/web/core/modules/file/src/FileAccessControlHandler.php
new file mode 100644 (file)
index 0000000..f4bda3c
--- /dev/null
+++ b/web/core/modules/file/src/FileAccessControlHandler.php
@@ -0,0 +1,131 @@
+<?php
+
+namespace Drupal\file;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Entity\EntityAccessControlHandler;
+use Drupal\Core\Entity\EntityInterface;
+use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Session\AccountInterface;
+
+/**
+ * Provides a File access control handler.
+ */
+class FileAccessControlHandler extends EntityAccessControlHandler {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function checkAccess(EntityInterface $entity, $operation, AccountInterface $account) {
+    /** @var \Drupal\file\FileInterface $entity */
+    if ($operation == 'download' || $operation == 'view') {
+      if (\Drupal::service('file_system')->uriScheme($entity->getFileUri()) === 'public') {
+        // Always allow access to file in public file system.
+        return AccessResult::allowed();
+      }
+      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[$entity->id()])) {
+            return AccessResult::allowed();
+          }
+        }
+        else {
+          return AccessResult::allowed();
+        }
+      }
+    }
+
+    if ($operation == 'delete' || $operation == 'update') {
+      $account = $this->prepareUser($account);
+      $file_uid = $entity->get('uid')->getValue();
+      // Only the file owner can delete and update the file entity.
+      if ($account->id() == $file_uid[0]['target_id']) {
+        return AccessResult::allowed();
+      }
+      return AccessResult::forbidden();
+    }
+
+    // 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.
+    // @todo Update comment to mention REST module when
+    //   https://www.drupal.org/node/1927648 is fixed.
+    return AccessResult::neutral();
+  }
+
+}