node_access

Definition

node_access($op, $node = NULL, $uid = NULL)
modules/node.module, line 2374

Description

Determine whether the current user may perform the given operation on the specified node.

Parameters

$op The operation to be performed on the node. Possible values are:

"view"
"update"
"delete"
"create"

$node The node object (or node array) on which the operation is to be performed, or node type (e.g. 'forum') for "create" operation.

$uid The user ID on which the operation is to be performed.

Return value

TRUE if the operation may be performed.

Name	Description
Node access rights	The node access system determines who can do what to which nodes.

Code

<?php
function node_access($op, $node = NULL, $uid = NULL) {
  // Convert the node to an object if necessary:
  if ($op != 'create') {
    $node = (object)$node;
  }
  // If the node is in a restricted format, disallow editing.
  if ($op == 'update' && !filter_access($node->format)) {
    return FALSE;
  }

  if (user_access('administer nodes')) {
    return TRUE;
  }

  if (!user_access('access content')) {
    return FALSE;
  }

  // Can't use node_invoke(), because the access hook takes the $op parameter
  // before the $node parameter.
  $access = module_invoke(node_get_base($node), 'access', $op, $node);
  if (!is_null($access)) {
    return $access;
  }

  // If the module did not override the access rights, use those set in the
  // node_access table.
  if ($op != 'create' && $node->nid && $node->status) {
    $grants = array();
    foreach (node_access_grants($op, $uid) as $realm => $gids) {
      foreach ($gids as $gid) {
        $grants[] = "(gid = $gid AND realm = '$realm')";
      }
    }

    $grants_sql = '';
    if (count($grants)) {
      $grants_sql = 'AND ('. implode(' OR ', $grants) .')';
    }

    $sql = "SELECT COUNT(*) FROM {node_access} WHERE (nid = 0 OR nid = %d) $grants_sql AND grant_$op >= 1";
    $result = db_query($sql, $node->nid);
    return (db_result($result));
  }
  return FALSE;
}
?>