+<?php
+
+namespace Drupal\quickedit\Access;
+
+use Drupal\Core\Access\AccessResult;
+use Drupal\Core\Routing\Access\AccessInterface;
+use Drupal\Core\Session\AccountInterface;
+use Drupal\Core\Entity\EntityInterface;
+
+/**
+ * Access check for editing entity fields.
+ */
+class EditEntityFieldAccessCheck implements AccessInterface, EditEntityFieldAccessCheckInterface {
+
+ /**
+ * Checks Quick Edit access to the field.
+ *
+ * @param \Drupal\Core\Entity\EntityInterface $entity
+ * The entity containing the field.
+ * @param string $field_name
+ * The field name.
+ * @param string $langcode
+ * The langcode.
+ * @param \Drupal\Core\Session\AccountInterface $account
+ * The currently logged in account.
+ *
+ * @return \Drupal\Core\Access\AccessResultInterface
+ * The access result.
+ *
+ * @todo Use the $account argument: https://www.drupal.org/node/2266809.
+ */
+ public function access(EntityInterface $entity, $field_name, $langcode, AccountInterface $account) {
+ if (!$this->validateRequestAttributes($entity, $field_name, $langcode)) {
+ return AccessResult::forbidden();
+ }
+
+ return $this->accessEditEntityField($entity, $field_name);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function accessEditEntityField(EntityInterface $entity, $field_name) {
+ return $entity->access('update', NULL, TRUE)->andIf($entity->get($field_name)->access('edit', NULL, TRUE));
+ }
+
+ /**
+ * Validates request attributes.
+ */
+ protected function validateRequestAttributes(EntityInterface $entity, $field_name, $langcode) {
+ // Validate the field name and language.
+ if (!$field_name || !$entity->hasField($field_name)) {
+ return FALSE;
+ }
+ if (!$langcode || !$entity->hasTranslation($langcode)) {
+ return FALSE;
+ }
+
+ return TRUE;
+ }
+
+}