Compress output html afterRender view cakephp 3

AppView.php

<?php

namespace App\View;

use Cake\View\View;
use Cake\Event\Event;

class AppView extends View
{

    public function initialize() {
        $this->eventManager()->on('View.afterLayout', [$this, 'afterLayout']);
    }

    public function afterLayout(Event $event) {
        $pageHtml =  $event->subject()->Blocks->get('content');

        $pageHtmlCompressed = $this->sanitize_output($pageHtml);

        $event->subject()->Blocks->set('content', $pageHtmlCompressed);
    }

    public function sanitize_output($buffer) {

        $search = array(
            '/\>[^\S ]+/s',  // strip whitespaces after tags, except space
            '/[^\S ]+\</s',  // strip whitespaces before tags, except space
            '/(\s)+/s',       // shorten multiple whitespace sequences
            '<!--(.*?)-->'
        );

        $replace = array(
            '>',
            '<',
            '\\1'
        );

        $buffer = preg_replace($search, $replace, $buffer);
        $buffer = str_replace('<>', '', $buffer);

        return $buffer;
    }
}