Programming new nodereference field

Hi All,

I'm trying to create a new type of nodereference field by which you can build a list of referenced nodes trough one suggest field. The referenced nodes are added via js to a table for nice viewing and to a hidden field to pass (the nids of) all referenced nodes after submitting. See the screenshot for a better understanding: http://www.wieni.be/noderefer_screen.jpg

All of this works fine, except the saving of the referenced nodes to the database. The values in my hidden field are not passed on. When I do a check in the action 'process form values' the parameter $items['nids'] is empty. Here are some parts of my code:

function noderefer_widget($op, &$node, $field, &$items) {
  if ($field['widget']['type']=="noderefer_select") {
  	
   switch ($op) {
    //... i took away some code here 
      case 'form':
            //... i took away some code here
         $form[$field['field_name']] = array('#tree' => TRUE);
	
         $form[$field['field_name']]['nids'] = array(
          '#type' => 'textfield',
          '#weight' => 10,
          '#default_value' => $items['default nids'],
          '#attributes' => array('class' => ($field['field_name'] ."-nids")),
         );
         
         return $form;
         break;
      case 'process form values':
	  drupal_set_message(var_export($items,true)); // <-- $items['nids'] is not there
           
      //... i took away some code here

So, if you're still following, the problem is that in alle examples I saw and also in the nodereference module itself, $items['nids'] just contains the values you filled in in the submit form. Except in my case, $items['nids'] does not exist or get striped along the way.

I realise using a hidden field to pass on nids might not be the.. cleaniest way to go so any suggestions on that matter are also greatly appreciated... thx!

Further reading about the _widget hook: http://www.drupalogy.com/api/function/hook_widget