Thread Field Editing (editpost.php)

[FatalBreeze]

Hello!
I created a new field to the thread table which is called thread_challenge.
I've added a radio button select on newthread, and the poster of the thread can select either the thread is considered a challenge or not (i've accomplished this using the article given in the articles section).

My problem is with editpost: when someone edits the thread, even if he changes the selection of the radio button, the value doesn't change in the DB.

Important to mention: the value is stored in the DB as 1=true (thread is a challenge), 0 = false (thread in not a challenge)

I'll show you my plugins:
editpost_start

PHP Code:

$show['challenge'] = false;
if (in_array($vbulletin->userinfo['usergroupid'],array(6,68,20,5,14)) AND ($threadinfo['firstpostid'] == $postinfo['postid']))
{
 $show['challenge'] = true;
} 


editpost_update_start

PHP Code:

$vbulletin->input->clean_array_gpc('p', array('thread_challenge' => TYPE_UINT));
$edit['thread_challenge'] =& $vbulletin->GPC['thread_challenge']; 


editpost_update_thread

PHP Code:

if ($threadinfo['firstpostid'] == $postinfo['postid'])
{
    $threadman->set('thread_challenge',$edit['thread_challenge']);
} 


And i also get this lovely error on editing:

Fatal error: Field thread_challenge is not defined in $validfields in class vb_datamanager_thread in /includes/class_dm.php on line 485

Edit:
Cool! I fixed the entire problem with adding in the vB_DataManager_Thread class the following function:

PHP Code:

 function verify_thread_challenge(&$thread_challenge) {
  if($thread_challenge !=1 )
  {
   $thread_challenge = 0;
  }
  return true;
 } 


And I added in vB_DataManager_Thread_FirstPost class to the var $validfields:

PHP Code:

  'thread_challenge'        => array(TYPE_UINT, REQ_NO,    VF_METHOD), 


But i rather use hooks than just edit the code, is there a more elegant way to do it?