node_query_node_access_alter

Versions

7

node_query_node_access_alter(QueryAlterableInterface $query)

Implement hook_query_TAG_alter().

Related topics

Node access rights

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

Code

modules/node/node.module, line 2654

<?php
function node_query_node_access_alter(QueryAlterableInterface $query) {
  // Skip the extra expensive alterations if site has no node access control
  // modules.
  if (!node_access_view_all_nodes()) {
    // Prevent duplicate records.
    $query->distinct();
    // The recognized operations are 'view', 'update', 'delete'.
    if (!$op = $query->getMetaData('op')) {
      $op = 'view';
    }
    // Skip the extra joins and conditions for node admins.
    if (!user_access('bypass node access')) {
      // The node_access table has the access grants for any given node.
      $access_alias = $query->join('node_access', 'na', 'na.nid = n.nid');
      $or = db_or();
      // If any grant exists for the specified user, then user has access to the
      // node for the specified operation.
      foreach (node_access_grants($op, $query->getMetaData('account')) as $realm => $gids) {
        foreach ($gids as $gid) {
          $or->condition(db_and()
            ->condition("{$access_alias}.gid", $gid)
            ->condition("{$access_alias}.realm", $realm)
          );
        }
      }

      if (count($or->conditions())) {
        $query->condition($or);
      }

      $query->condition("{$access_alias}.grant_$op", 1, '>=');
    }
  }
}
?>

Login or register to post comments