PHP error with Computed field

Question

here is my code:

$nid = $entity->field_empf_number['und']['0']['nid'];  
$result = db_query("SELECT MAX(entity_id) FROM field_data_field_empf_number WHERE field_empf_number_nid = $nid")->fetchField();  
if (isset($result)){  
  $n = $result ;  
  $node = node_load($n);  
  $node->field_empf_stat['und']['0']['value'] = 'off';  //list field  
  node_save($node);  
}  
$entity_field[0]['value'] = $result;`

when add new node (if there is previous node i mean the if statement return true ) this error message show up:

Fatal error: Maximum function nesting level of '100' reached, aborting! in C:\wamp\www\finance\includes\database\database.inc on line 429

I googled but i did not found any answers.

Answer 1

Try to change the node_save($node) to drupal_register_shutdown_function('node_save', $node). It will remove the old node saving process from the actual node saving. But I don't think, that type of code should have place within a computed field. The computed field good to modify the same field. It isn't designed for modifying other data of your system. These code should be in a custom module in hook_node_presave().

Answer 2

The code for the computed field should preferrably be placed in your module, not in your database. This will make your code much easier to debug so the abovementioned errors won't happen.

Use the computed field hook - here is a nice (tutorial).

Here are some code examples.