PHP Current class loader

Plugin.php

<?php
namespace ddd;

if(!class_exists('Plugin')){
  class Plugin{

    function __construct(){
      $this->loadCore();
    }

    private function loadCore(){
      $this->loadWpCore();
      $this->loadClass();
      $this->loadShortcode();
      $this->loadAction();
    }


    private function loadWpCore(){
      $dir = dirname(__FILE__).'/../wp-core/';
      if (is_dir($dir))
      {
        if ($dh  = opendir($dir))
        {
          while ($filename = readdir($dh))
          {
            if (strstr($filename,'.php') )
              require_once($dir.$filename);
          }
        }
        else
        {
          echo " can't open dir <br>";
        }
      }
      else
      {
        echo $dir.' incorect path to dir<br>';
      }
    }//loadWpCore

    private function loadClass(){
      $dir = dirname(__FILE__).'/../class/';
      if (is_dir($dir))
      {
        if ($dh  = opendir($dir))
        {
          while ($filename = readdir($dh))
          {
            if (strstr($filename,'.php') )
              require_once($dir.$filename);
          }
        }
        else
        {
          echo " can't open dir <br>";
        }
      }
      else
      {
        echo $dir.' incorect path to dir<br>';
      }
    }//loadClass

    private function loadShortcode(){

      $dir = dirname(__FILE__).'/../shortcode/';
      if (is_dir($dir))
      {
        if ($dh  = opendir($dir))
        {
          while ($filename = readdir($dh))
          {
            if (strstr($filename,'.php') )
              require_once($dir.$filename);
          }
        }
        else
        {
          echo " can't open dir <br>";
        }
      }
      else
      {
        echo $dir.' incorect path to dir<br>';
      }
    }//loadShortcode

    private function loadAction(){
      $dir = dirname(__FILE__).'/../action/';
      if (is_dir($dir))
      {
        if ($dh  = opendir($dir))
        {
          while ($filename = readdir($dh))
          {
            if (strstr($filename,'.php') )
              require_once($dir.$filename);
          }
        }
        else
        {
          echo " can't open dir <br>";
        }
      }
      else
      {
        echo $dir.' incorect path to dir<br>';
      }
    }//loadAction

  }//Plugin

  new Plugin();

}


?>