function node_query_node_access_alter

node_query_node_access_alter(AlterableInterface $query)

Implements hook_query_TAG_alter().

This is the hook_query_alter() for queries tagged with 'node_access'. It adds node access checks for the user account given by the 'account' meta-data (or current user if not provided), for an operation given by the 'op' meta-data (or 'view' if not provided; other possible values are 'update' and 'delete').

Queries tagged with 'node_access' that are not against the {node} table must add the base table as metadata. For example:

  $query
    ->addTag('node_access')
    ->addMetaData('base_table', 'taxonomy_index');

Related topics

Node access rights

The node access system determines who can do what to which nodes.

File

core/modules/node/node.module, line 1023

The core module that allows content to be submitted to the site.

Code

function node_query_node_access_alter(AlterableInterface $query) {
  // Read meta-data from query, if provided.
  if (!$account = $query->getMetaData('account')) {
    $account = \Drupal::currentUser();
  }
  if (!$op = $query->getMetaData('op')) {
    $op = 'view';
  }

  // If $account can bypass node access, or there are no node access modules,
  // or the operation is 'view' and the $account has a global view grant
  // (such as a view grant for node ID 0), we don't need to alter the query.
  if ($account->hasPermission('bypass node access')) {
    return;
  }
  if (!count(\Drupal::moduleHandler()->getImplementations('node_grants'))) {
    return;
  }
  if ($op == 'view' && node_access_view_all_nodes($account)) {
    return;
  }

  $tables = $query->getTables();
  $base_table = $query->getMetaData('base_table');
  // If the base table is not given, default to one of the node base tables.
  if (!$base_table) {
    /** @var \Drupal\Core\Entity\Sql\DefaultTableMapping $table_mapping */
    $table_mapping = \Drupal::entityTypeManager()->getStorage('node')->getTableMapping();
    $node_base_tables = $table_mapping->getTableNames();

    foreach ($tables as $table_info) {
      if (!($table_info instanceof SelectInterface)) {
        $table = $table_info['table'];
        // Ensure that 'node' and 'node_field_data' are always preferred over
        // 'node_revision' and 'node_field_revision'.
        if ($table == 'node' || $table == 'node_field_data') {
          $base_table = $table;
          break;
        }
        // If one of the node base tables are in the query, add it to the list
        // of possible base tables to join against.
        if (in_array($table, $node_base_tables)) {
          $base_table = $table;
        }
      }
    }

    // Bail out if the base table is missing.
    if (!$base_table) {
      throw new Exception(t('Query tagged for node access but there is no node table, specify the base_table using meta data.'));
    }
  }

  // Update the query for the given storage method.
  \Drupal::service('node.grant_storage')->alterQuery($query, $tables, $op, $account, $base_table);

  // Bubble the 'user.node_grants:$op' cache context to the current render
  // context.
  $request = \Drupal::requestStack()->getCurrentRequest();
  $renderer = \Drupal::service('renderer');
  if ($request->isMethodSafe() && $renderer->hasRenderContext()) {
    $build = ['#cache' => ['contexts' => ['user.node_grants:' . $op]]];
    $renderer->render($build);
  }
}