node_access_test_language.module

<?php

/**
 * @file
 * Test module with a language-aware node access implementation.
 *
 * The module adds a 'private' field to page nodes that allows each translation
 * of the node to be marked as private (viewable only by administrators).
 */
use Drupal\Core\Entity\EntityInterface;

/**
 * Implements hook_node_grants().
 *
 * This module defines a single grant realm. All users belong to this group.
 */
function node_access_test_language_node_grants($account, $op) {
  $grants['node_access_language_test'] = array(
    7888,
  );
  return $grants;
}

/**
 * Implements hook_node_access_records().
 */
function node_access_test_language_node_access_records(EntityInterface $node) {
  $grants = array();

  // Create grants for each translation of the node.
  foreach ($node
    ->getTranslationLanguages() as $langcode => $language) {

    // If the translation is not marked as private, grant access.
    $grants[] = array(
      'realm' => 'node_access_language_test',
      'gid' => 7888,
      'grant_view' => empty($node->field_private[$langcode][0]['value']) ? 1 : 0,
      'grant_update' => 0,
      'grant_delete' => 0,
      'priority' => 0,
      'langcode' => $langcode,
    );
  }
  return $grants;
}

/**
 * Implements hook_enable().
 *
 * Creates the 'private' field, which allows the node to be marked as private
 * (restricted access) in a given translation.
 */
function node_access_test_language_enable() {
  $field_private = array(
    'field_name' => 'field_private',
    'type' => 'list_boolean',
    'cardinality' => 1,
    'translatable' => TRUE,
    'settings' => array(
      'allowed_values' => array(
        0 => 'Not private',
        1 => 'Private',
      ),
    ),
  );
  $field_private = field_create_field($field_private);
  $instance = array(
    'field_name' => $field_private['field_name'],
    'entity_type' => 'node',
    'bundle' => 'page',
    'widget' => array(
      'type' => 'options_buttons',
    ),
  );
  $instance = field_create_instance($instance);
}

/**
 * Implements hook_disable().
 */
function node_access_test_language_disable() {
  field_delete_instance(field_read_instance('node', 'field_private', 'page'));
}