Hiding Fields in newly created content based on configuration in existing node

Hi Quicksketch,
I'm thinking this will probably be in another module, although the functionality request is tied closely to NodeReferenceURL, and if it could be included in NodeReferenceURLwidget that'd be great.

More, I'm looking for ideas and tips from others who may have been in a similar situation, I imagine this is functionality that many others would like to have.

I'm asking for an easy way to specify fields to be hidden from display in a piece of content (A) that is referencing another piece of content (B) via Node Reference. There would be a new field that appears in the field listing of B when editing the node that could be configured (by those with the right permissions) that would allow for hiding/disabling any of the fields that appear in Content A. This would allow for different pieces of content (say Events (B)) to specify which fields are needed to be collected for registering for that event in the Event Registration content type (A).

I may write this myself but wanted to make sure I'm not duplicating effort.

OK, I found an easy way to do this, and I wanted to share it with others who might be wanting to do this.

Here is an example based on a CCK type 'event' and another type called 'event_registration'.
event_registration has the field field_reg_event which is a Node Reference to CCK types of 'event', and it uses Node Reference URL. The 'event_registration' CCK type has many fields in it, some of which are not relevant to a given event. To easily configure the fields to be hidden for a given event's event registration form:

1a. Add the field 'field_event_fields_to_hide' to the 'event' CCK type as a text field using the [Check boxes/radio buttons] Form element to edit the data.

1b. Make the Number of Values for this field set to 'Unlimited', and then
enter the names of the fields that you want to be able to hide
as they appear in the Name column of the [Manage Fields] tab of the CCK type.
You can come back and add other fields to this list as needed.

1c. Save this field. Optional: Set default value for this fields;
typically you'll want to default all fields to be hidden (checked)
and then uncheck the fields to make appear for the given event.

2. Add the following code to a custom module for the site. If there
is already a hook_form_alter() function, just add the code inside. Alter
the CCK names event and event_registration to your own specific CCK type
names, and set MODULE_NAME equal to the name of your module

/*
 * Implements hook_form_alter().
 */
function MODULE_NAME_form_alter(&$form, $form_state, $form_id){
 
  if($form_id == 'event_registration_node_form'){
 
      // hide fields based on configuration in the node that is referred to
      // first get values from the event node
      $action = explode('/',$form['#action']); 

      if($action[2] == 'add'){
        // get the referred nid from the form
        if(!isset($action[4]))
          return;
        $event_nid = $action[4];
      }else{
        // get the referred nid from data  
        $form_object = $form['#parameters'][2];
        $event_nid = $form_object->field_reg_event[0]['nid'];
      }

      if(strlen($event_nid)){
        $event = node_load($event_nid);
        foreach ($event->field_event_fields_to_hide AS $idx => $field_name_arr) {
          $fieldname = $field_name_arr['value'];
          unset($form[$fieldname]);
        }
      }else{
        drupal_set_message('referred node nid not found');
      }

   }

}

I don't think there is a way to include this functionality into this module, but if there was I think it'd be a nice addition. Perhaps the answer is to create another module to do this sort of thing so that no PHP coding would be needed.

I updated the code in the comment above to make this fix, thanks for posting your update, pauljp

Here is the PHP code to use to set the default values in the "fields_to_hide" field of the referenced node.

  $content_types = _content_type_info();
  $fields = $content_types['content types']['your_content_type_name_with_fields_to_hide']['fields'];
  $field_names=array();
  foreach ($fields AS $field_name=>$field) {
    $field_names[$field_name]=$field_name;
 }
 return $field_names;