Сниппет вывода дополнительных параметров

<form id="search-global-form" class="form-search" action="[[~[[+landing:default=`[[*id]]`]]]]" method="[[+method:default=`get`]]">
     
        <input type="text" class="input-big search-query" name="[[+searchIndex]]" id="[[+searchIndex]]" value="[[+searchValue]]" autocomplete="off" data-provide="typeahead"
        data-items="4" data-source='[ [[getPagetitles? &parents=`8,9`]] ]'/>
        <input type="hidden" name="id" value="[[+landing:default=[[*id]]]]" /> 
        <button type="submit" class="btn" value="">Search</button>
   
</form>

<?
/* getPagetitles snippet
use: [[getPagetitles? &parents=`parentsIDs`]] */
if (!$parents) return;
$res = $modx->getCollection('modResource',array('parent:IN' => explode(',', $parents)));
$output = '';
foreach ($res as $v) {
        $output.= '"'.$v->get('pagetitle').'",';
}; 
$output = substr($output,0,-1);
return $output;