clearCahe

<?php
//mgr events
if($modx->context->key == "mgr"){
    switch($modx->event->name){
        case "OnBeforeCacheUpdate":
            if (!$obj = $modx->getObject('modSystemSetting', array('key' => 'site_file_version'))) {
                $obj = $modx->newObject('modSystemSetting');
                $obj->fromArray(array(
                    'key' => 'site_file_version',
                    'xtype' => 'textfield',
                    'namespace' => 'core',
                    'area' => 'site',
                    'editedon' => null,
                ), '', TRUE);
            }
            $obj->set('value',substr(md5(time()), 0, 12));
            $obj->save();
            break;
    }
    return;
}