Вячеслав Варов

if (!function_exists('human_filesize')) {
    function human_filesize($bytes, $decimals = 2) {
      $sz = ['B','Kb','Mb','Gb','Tb','Pb'];
      $factor = floor((strlen($bytes) - 1) / 3);
      return sprintf("%.{$decimals}f", $bytes / pow(1024, $factor)) . ' ' .@$sz[$factor];
    }
}

<?php
switch($modx->event->name) { 
    case 'OnDocFormSave':
    if ($resource->get('class_key') == 'msProduct') {
        $template = $resource->get('template'); {
            if ($template == 15) {
                $old_price = $resource->get('old_price');
	            $sale_size = $resource->get('sale_size');
	            $resource->set('price', $old_price * (100 - $sale_size) / 100);
	            $resource->save();
            }
        }
    }
    break;
}

{set $res_array = '!msProducts' | snippet : [
    'parents' => $id,
    'limit' => 0,
    'return' => 'json'
]}
    {set $full_colors_array = '!sort3' | snippet : ['data' => $res_array, 'cols' => 6] | fromJSON}
     {foreach $full_colors_array as $res}
        <div class="kc-slide">
            <div class="kc-item-block">
              <div class="kc-item-image-wrap">
                <img class="kc-item-img" src="{$res.thumb}">
              </div>
              <div class="kc-item-name">{$res.pagetitle} </div>
            </div>
        </div>
    {/foreach}
    {set $full_colors_array = '!sort3' | snippet : ['data' => $res_array, 'cols' => 6] | fromJSON}

{set $res_array = '!msProducts' | snippet : [
    'parents' => $id,
    'limit' => 0,
    'return' => 'json'
]}
    {set $full_colors_array = '!sort3' | snippet : ['data' => $res_array, 'cols' => 6] | fromJSON}
     {foreach $full_colors_array as $res}
        <div class="kc-slide">
            <div class="kc-item-block">
              <div class="kc-item-image-wrap">
                <img class="kc-item-img" src="{$res.thumb}">
              </div>
              <div class="kc-item-name">{$res.pagetitle} </div>
            </div>
        </div>
    {/foreach}

{if $key | notin : $array} {* не выбивает синтаксическую ошибку, но не работает*} 
{if $key | not in : $array} {* выбивает синтаксическую ошибку*}

{if $key | in : $array}{else}выполняем{/if} {*ну такое*}

{set $condition = 1}
{switch $condition}
{case 0}
    ...
{case 1}
{case 2}
    не сработает   
{case default}
    ...
{/switch}