<?php
 
class Core {
      public $MySQLi;
      public $instance;
 
      public static function getInstance() {
         static $instance = null;
         if($instance == null) {
             $instance = new Core();
          }
         return $instance;
      }
 
     private function __construct() {
        require $_SERVER['DOCUMENT_ROOT'] . '/Core/Configuration.php';
        $this->MySQLi = new MySQLi($host, $user, $pass, $db);
          if ($this->MySQLi->connect_error) {
            echo 'ERROR MySQLi';
          }
      }
 
      private function __destruct() {
         $this->MySQLi->close();
      }
   }
 
   $heart = Core::getInstance();
 
?>
 

<?php
 
  class Templates {
    public static function show($theme, $file_html, $lang) {
        $file = $_SERVER['DOCUMENT_ROOT'] . '/Templates/' . $theme . '/' . $file_html . '.html';
        $open = fopen($file, 'r');
        $html = fread($open, filesize($file));
      foreach ($lang as $key => $value) {
        $html = str_replace('%' . $key . '%', $value, $html);
      }
      echo $html;
    }
  }
  $templates = new Templates();
 
?>