Callback Function and $GLOBAL variable

[Farcaster]

I am writing a modification that adds a custom bbcode tag.

So, I have this that is being eval'd on the bbcode_create hook:

PHP Code:

if (!function_exists('handle_bbcode_roll'))
{

    function handle_bbcode_roll(&$parser, $text, $option)
    {

        // MOVED FROM IF (class_exists...
        $GLOBALS['dicehistory'] .= "$text";
        
        if (class_exists('vB_BbCodeParser_Wysiwyg') AND is_a($parser, 'vB_BbCodeParser_Wysiwyg'))
        {
            return $text;
        } else {
            
            
            return "<div><span class=\"die_description\">* $text *</span></div>";        
        }          
    }
}

$this->tag_list['option']['roll'] = array(
        'callback' => 'handle_external',
        'strip_empty' => false,
        'stop_parse' => true,
        'disable_smilies' => true,
        'disable_wordwrap' => true,
        'strip_space_after' => 1,
        'external_callback' => 'handle_bbcode_roll'
    ); 


Later in the postdata_presave, I am trying to access this $GLOBALS['dicehistory'], and I am getting nothing at all. It seems that I cannot access the global array from within the callback function. Can anyone tell me why this is and how I can pass something back to be accessed during postdata_presave? (Forget that this particular example is pretty meaningless.. I do have a reason for wanting to do this)