"Inherit Selected Template" in Revolution?

<?php
if ($mode != modSystemEvent::MODE_NEW) return;

/* Get parent ID */
$parentId = $resource->get('parent');

/* Get the TV object */
$tvObj = $modx->getObject('modTemplateVar', array('name' => 'ChildTemplate'));



/* Act only if there is a parent ID (i.e., doc is not at the root) and the TV object exists */
 
if ($tvObj) {

    /* Get value of TV for parent */
        if ($parentId) {

            /* Get the TV's value for that ancestor */
            $tv = $tvObj->renderOutput($parentId);

            if ($tv) {
                /* $tv is set -- use it for current resource's template value */
                if (is_numeric($tv)) {
                    /* It's a number -- user it */
                    $tid = $tv;
                } else {
                    /* It's a template name -- get the ID */
                    $t = $modx->getObject('modTemplate', array('templatename' => $tv));

                    if ($t) {
                        $tid = $t->get('id');
                    }
                }
                if($tid){
                    $resource->set('template', $tid);
                    $resource->save();                
                }
             }
        }
}

$tv = $tvObj->renderOutput($parentId);

$tv = $tvObj->getValue($parentId);