Drupal 7 Module Development

Node Access
This permission will inform our use of hook_node_access_records_alter().
hook_node_access_records_alter() is almost identical to hook_node_access_
records(). The function passes the &$grants array by reference, plus the $node
being acted upon.
/**
* Implement hook_node_access_records_alter().
*
* If a user saves content, make sure that an access record for the
* 'authenticated user' role should actually be stored.
*/
function role_access_extend_node_access_records_alter(&$grants, $node)
{
If we run a var_dump() on the typical $grants being passed to this function, we see
an array that should seem familiar:
array(2) {
[0]=>
array(6) {
["realm"]=> string(11) "role_access"
["gid"]=> int(2)
["grant_view"]=> int(1)
["grant_update"]=> int(1)
["grant_delete"]=> int(1)
["priority"]=> int(0)
}
[1]=>
array(6) {
["realm"]=> string(11) "role_access"
["gid"]=> int(5)
["grant_view"]=> int(1)
["grant_update"]=> int(1)
["grant_delete"]=> int(1)
["priority"]=> int(0)
}
}
What we need to do is make sure that the realm 'role_access' only returns grant id 2
if the user's role allows it. So we run a check for the user's permissions and modify
the $grants array as needed.
// We cannot use the global $user here; we want the creator/editor
of the content.
$account = user_load($node->uid);
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