Translating snippet from Evo to Revo: Am I doing it right?

$doc = $this->modx->getPageInfo($id, 0, 'type,published,hidemenu,deleted' );

$resource = $this->modx->getObject('modResource', $id);
$doc = $resource->get('type,published,hidemenu,deleted');

  function GetTVArray()
  {
  // Gets an array of all template variables
    $table = $this->modx->getFullTableName('site_tmplvars');
    $tvs = $this->modx->db->select('name', $table);
    // TODO: make it so that it only pulls those that apply to the current template
    $dbfields = array();
    while ( $dbfield = $this->modx->db->getRow( $tvs ) )
    {
      $dbfields[] = $dbfield['name'];
    }
    return $dbfields;
  }

$doc = $resource->get(array('type','published','hidemenu','deleted'));

/* assuming you have the ID of the template */
$c = $modx->newQuery('modTemplateVar');
$c->innerJoin('modTemplateVarTemplate','TemplateVarTemplates');
$c->where(array(
    'TemplateVarTemplates.templateid' => $templateId,
));
$c->sortby('TemplateVarTemplates.rank','ASC');
$tvs = $modx->getObject('modTemplateVar',$c);

$names = array();
foreach ($tvs as $tv) {
   $names[] = $tv->get('name');
}
$names = array_unique($names);

    $siblings = $this->modx->getAllChildren($parentId, 'menuindex', 'ASC', 'id');

    $c = $modx->newQuery('modResource');
    $c->where(array(
       'parent' => $parentId,
    ));
    $c->sortby('menuindex','ASC');
    $siblings = $modx->resource->getMany('Children',$c);

  function GetSiblingId( $id )
  {
    global $modx;
    // Gets the next sibling.
    // Returns -1 if one doesn't exist

    $siblingId = -1;

    // If the document is the document root, then it has no siblings
    if ( $id == 0 )
    {
      return -1;
    }

    // Get the parent document id
    $parentId = $this->GetParentId( $id );

    // Get the immediate siblings (and the current document)
    $c = $modx->newQuery('modResource');
    $c->where(array(
       'parent' => $parentId,
    ));
    $c->sortby('menuindex','ASC');
    $siblings = $modx->resource->getMany(array('Children','id'),$c);
    echo "GetSiblingId: ";
    print_r($siblings);

    // Calculate the number of siblings
    $nSiblings = count( $siblings ) - 1;

    $currentIndex = -1;
    // Find the current document in the list of siblings
    foreach ( $siblings as  $index => $sibling )
    {
      if ( $sibling['id'] == $id )
      {
        $currentIndex = $index;
        break;
      }
    }
    if ($currentIndex == -1)
    {
      return $siblingId;
    }

    switch ( $this->rel )
    {
      case 'prev':
        if ( $currentIndex > 0 )
        {
          $siblingId = $siblings[$currentIndex-1]['id'];
          return $siblingId;
        }
        break;
      case 'next':
        if ( $currentIndex < $nSiblings )
        {
          $siblingId = $siblings[$currentIndex+1]['id'];
          return $siblingId;
        }
        break;
      default:
        return $siblingId;
    }
    return $siblingId;
  }

  function GetParentId( $id )
  {
    // Gets the id of the parent.
    // If the document is the root, and so has no parent, -1 is returned
    if ( $id <= 0 ) {
      return -1;
    }
    $resource = $this->modx->getObject('modResource', $id);
    $currentDoc = $resource->get('parent');

    return $currentDoc['parent'];
  }

$parent = $modx->resource->getOne('Parent);
$siblings = $parent->getMany('Children',$c);

$modx->getCollection('modResource',$c);