--- /dev/null
+<?php
+
+/**
+ * @file
+ * Defines a field type and its formatters and widgets.
+ */
+
+use Drupal\Core\Entity\FieldableEntityInterface;
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Entity\Exception\FieldStorageDefinitionUpdateForbiddenException;
+use Drupal\Core\Field\FieldDefinitionInterface;
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\field\FieldStorageConfigInterface;
+
+/**
+ * Implements hook_field_widget_info_alter().
+ */
+function field_test_field_widget_info_alter(&$info) {
+ $info['test_field_widget_multiple']['field_types'][] = 'test_field';
+ $info['test_field_widget_multiple']['field_types'][] = 'test_field_with_preconfigured_options';
+}
+
+/**
+ * Implements hook_field_storage_config_update_forbid().
+ */
+function field_test_field_storage_config_update_forbid(FieldStorageConfigInterface $field_storage, FieldStorageConfigInterface $prior_field_storage) {
+ if ($field_storage->getType() == 'test_field' && $field_storage->getSetting('unchangeable') != $prior_field_storage->getSetting('unchangeable')) {
+ throw new FieldStorageDefinitionUpdateForbiddenException("field_test 'unchangeable' setting cannot be changed'");
+ }
+}
+
+/**
+ * Sample 'default value' callback.
+ */
+function field_test_default_value(FieldableEntityInterface $entity, FieldDefinitionInterface $definition) {
+ return [['value' => 99]];
+}
+
+/**
+ * Implements hook_entity_field_access().
+ */
+function field_test_entity_field_access($operation, FieldDefinitionInterface $field_definition, AccountInterface $account, FieldItemListInterface $items = NULL) {
+ if ($field_definition->getName() == "field_no_{$operation}_access") {
+ return AccessResult::forbidden();
+ }
+
+ // Only grant view access to test_view_field fields when the user has
+ // 'view test_view_field content' permission.
+ if ($field_definition->getName() == 'test_view_field' && $operation == 'view') {
+ return AccessResult::forbiddenIf(!$account->hasPermission('view test_view_field content'))->cachePerPermissions();
+ }
+
+ return AccessResult::allowed();
+}