Add an auto-increment integer at the end of an url when same alias name is used

<?php

// Get the current event
$e = &$modx->event;
$r = &$e->params['resource'];

// set new alias
$alias = $r->get('alias');
$id = $r->get('id');
$pagetitle = $r->get('pagetitle');


//here you need to check for existing aliases and create a new incremented one
//this needs some testing
$c = $modx->newQuery('modResource', array('alias' => $alias, 'id:!=' => $id));
if ($collection = $modx->getCollection('modResource', $c)) {
    foreach ($collection as $key => $object) {
        $existing[] = $object->get('alias');
    }

    $c = $modx->newQuery('modResource', array('pagetitle' => $pagetitle, 'id:!=' => $id));
    if ($collection = $modx->getCollection('modResource', $c)) {
        foreach ($collection as $key => $object) {
            $existing[] = $object->get('alias');
        }
    }

    $loop = true;
    $i = 0;
    while ($loop) {
        if ($i == 0) {
            $suffix = '';
        } else {
            $suffix = $i < 10 ? '-0' . $i : '-' . $i;
        }


        $newalias = $pagetitle . $suffix;
        $newalias = $r->cleanAlias($newalias);
        $loop = in_array($newalias, $existing);
        $i++;
    }

    $r->set('alias', $newalias);
}

$newalias = $r->cleanAlias($newalias);