API@RTK0.NET

1. drupal
   1. 7

Alter user access rules when trying to view, edit or delete a node.

Node access modules establish rules for user access to content. hook_node_grants() defines permissions for a user to view, edit or delete nodes by building a $grants array that indicates the permissions assigned to the user by each node access module. This hook is called to allow modules to modify the $grants array by reference, so the interaction of multiple node access modules can be altered or advanced business logic can be applied.

Parameters

&$grants The $grants array returned by hook_node_grants().

$account The user account requesting access to content.

$op The operation being performed, 'view', 'update' or 'delete'.

Developers may use this hook to either add additional grants to a user or to remove existing grants. These rules are typically based on either the permissions assigned to a user role, or specific attributes of a user account.

See also

hook_node_grants()

The resulting grants are then checked against the records stored in the {node_access} table to determine if the operation may be completed.

A module may deny all access to a user by setting $grants to an empty array.

hook_node_access_records()

hook_node_access_records_alter()

Related topics

Node access rights

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

Hooks

Allow modules to interact with the Drupal core.

Code

drupal/modules/node/node.api.php, line 377

<?php
function hook_node_grants_alter(&$grants, $account, $op) {
  // Our sample module never allows certain roles to edit or delete
  // content. Since some other node access modules might allow this
  // permission, we expressly remove it by returning an empty $grants
  // array for roles specified in our variable setting.

  // Get our list of banned roles.
  $restricted = variable_get('example_restricted_roles', array());

  if ($op != 'view' && !empty($restricted)) {
    // Now check the roles for this account against the restrictions.
    foreach ($restricted as $role_id) {
      if (isset($user->roles[$role_id])) {
        $grants = array();
      }
    }
  }
}
?>